JP5311712B2 - Anthracene derivative and light emitting element and light emitting device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a luminescent substance resistant to repeated oxidation reaction, and to provide a light-emitting element resistant to repeated reductive reaction as well. <P>SOLUTION: The luminescent substance is an anthracene derivative of the general formula(1)( wherein, R<SP>1</SP>is H or a 1-4C alkyl; R<SP>2</SP>is H, a 1-4C alkyl or 6-12C aryl; R<SP>3</SP>is H, a 1-4C alkyl or 6-12C aryl; Ph<SP>1</SP>is phenyl; and X<SP>1</SP>is a 6-15C arylene group ). <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to an anthracene derivative, and particularly to an anthracene derivative that can be used as a material for manufacturing a light-emitting element.

  In recent years, many light-emitting elements used for displays and the like have a structure in which a layer containing a light-emitting substance is sandwiched between a pair of electrodes. In such a light emitting element, light is emitted when excitons formed by recombination of electrons injected from one electrode and holes injected from the other electrode return to the ground state.

  In the field of light-emitting elements, in order to obtain a light-emitting element that has good light emission efficiency and chromaticity or can prevent quenching, various studies have been conducted on substances that are materials for manufacturing the light-emitting element. .

  For example, Patent Document 1 discloses an organic EL element material having high light emission efficiency and long life.

  By the way, in a light emitting element, a current flows between electrodes by exchanging holes or electrons. At this time, the luminescent material or the like that has received holes or electrons, that is, the oxidized or reduced luminescent material or the like may not return to neutrality but may change to a different property or structure. And if the change of the property and structure of such a luminescent substance is accumulated, the characteristic of a light emitting element may also change.

  Therefore, there is a demand for the development of a luminescent material whose properties are not easily changed by oxidation or reduction.

JP 2001-131541 A

  An object of the present invention is to provide a substance that is resistant to repeated oxidation reactions and can be used as a material for a light-emitting element. It is another object of the present invention to provide a light-emitting element and a light-emitting device in which a reduction in operating characteristics of the light-emitting element due to a change in characteristics of a substance due to repeated oxidation reactions is reduced.

  One aspect of the present invention is an anthracene derivative represented by the general formula (1).

In the general formula (1), R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ² represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. R ³ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. Ph ¹ represents a phenyl group. The phenyl group may have a substituent or may be unsubstituted. X ¹ represents an arylene group having 6 to 15 carbon atoms. The arylene group may have a substituent or may be unsubstituted.

  One aspect of the present invention is an anthracene derivative represented by the general formula (2).

In the general formula (2), R ⁴ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ^{5 to} R ⁸ represent hydrogen or an aromatic ring in which R ⁵ and R ⁶ , R ⁷ and R ⁸ are bonded to each other. R ⁹ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. R ¹⁰ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. Ph ² represents a phenyl group. The phenyl group may have a substituent or may be unsubstituted.

  One aspect of the present invention is an anthracene derivative represented by General Formula (3).

In General Formula (3), R ¹¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms. R ¹² represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. R ¹³ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. Ph ³ represents a phenyl group. The phenyl group may have a substituent or may be unsubstituted.

  One aspect of the present invention is an anthracene derivative represented by General Formula (4).

In General Formula (4), R ¹⁴ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. R ¹⁵ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted. Ph ⁴ represents a phenyl group. The phenyl group may have a substituent or may be unsubstituted.

  One aspect of the present invention is an anthracene derivative represented by General Formula (5).

In the general formula (5), R ¹⁶ represents hydrogen or an alkyl group having 1 to 4 carbon atoms.

  One aspect of the present invention is an anthracene derivative represented by General Formula (6).

In the general formula (6), ^{X 2} represents an arylene group having 6 to 15 carbon atoms. The arylene group may have a substituent or may be unsubstituted.

  One aspect of the present invention is an anthracene derivative represented by General Formula (7).

In General Formula (7), R ¹⁷ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted.

  One aspect of the present invention is an anthracene derivative represented by General Formula (8).

In General Formula (8), R ¹⁸ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. The aryl group may have a substituent or may be unsubstituted.

  One embodiment of the present invention is a light-emitting element including a layer containing an anthracene derivative represented by any one of general formulas (1) to (8) between electrodes.

  One embodiment of the present invention is a light-emitting device using a light-emitting element including an anthracene derivative represented by any one of general formulas (1) to (8).

  One embodiment of the present invention is a light-emitting device including a light-emitting element including an anthracene derivative represented by any one of general formulas (1) to (8) in a pixel portion.

  One embodiment of the present invention is an electronic device on which a light-emitting device including a light-emitting element including an anthracene derivative represented by any one of general formulas (1) to (8) is mounted.

  By implementing the present invention, a substance that has excellent resistance to repeated oxidation reactions and can be used as a material for manufacturing a light-emitting element can be obtained. In addition, by carrying out the present invention, it has excellent resistance to repeated oxidation reactions and also has excellent resistance to repeated reduction reactions, and can be used as a material for manufacturing a light-emitting element. A substance can be obtained.

  By implementing the present invention, a light-emitting element that can reduce deterioration in element characteristics that can be caused by a substance used for forming a layer provided between electrodes repeating an oxidation reaction can be obtained. In addition, a light-emitting element that can exhibit stable light emission for a long period of time can be obtained with little change in characteristics of the light-emitting element due to a change in properties of the light-emitting substance due to repeated oxidation reactions.

  Hereinafter, one embodiment of the present invention will be described. However, the present invention can be implemented in many different modes, and those skilled in the art can easily understand that the modes and details can be variously changed without departing from the spirit and scope of the present invention. Is done. Therefore, the present invention is not construed as being limited to the description of the embodiment.

(Embodiment 1)
One embodiment of the anthracene derivative of the present invention will be described.

  Examples of the anthracene derivative of the present invention include anthracene derivatives represented by structural formulas (1) to (40).

  These anthracene derivatives include, for example, a compound A containing an anthracene such as 9,10-dibromoarylanthracene in the skeleton and a compound B containing an arylaminocarbazole in the skeleton as represented by the following synthesis scheme (a-1). Obtained by a coupling reaction. The method for synthesizing the anthracene derivative of the present invention is not limited to the synthesis method described here, and may be synthesized by other synthesis methods.

In the synthesis scheme (a-1), R ¹⁹ represents hydrogen or tert-butyl. R ²⁰ is any one selected from hydrogen, methyl, ethyl, alkyl groups having 1 to 4 carbon atoms such as tert-butyl, and aryl groups having 1 to 12 carbon atoms such as phenyl, biphenyl and naphthyl. Represents a group. The aryl group may have a substituent or may be unsubstituted. Ph ⁵ represents a phenyl group. The phenyl group may have a substituent or may be unsubstituted. X ³ represents an arylene group having 6 to 15 carbon atoms such as phenylene, naphthylene, anthrylene, 9,9-dimethylfluorene-2,7-diyl.

  Here, as represented by the synthesis scheme (a-2), compound A can be obtained using dibromoarene (compound C) and a compound containing anthraquinone in the skeleton as main raw materials. In the compound B, as represented by the synthesis scheme (a-3), after the hydrogen at the 3-position of the compound containing carbazole in the skeleton is substituted with bromo, the bromo is further substituted with an amino group. It is obtained by reacting.

  In this embodiment, 9,10-bis (bromoaryl) anthracene is used as the compound A containing an anthracene skeleton, but 9,10-bis (iodoaryl) anthracene or the like may be used in addition to this. 9,10-bis (iodoaryl) anthracene can be obtained by changing 1,5-diiodonaphthalene or 2,7-diiodo-9,9-dimethylfluorene instead of compound C in the synthesis represented by the synthesis scheme (a-2). Is obtained by using a gyrodelane. In addition, 1,5-diiodonaphthalene, 2,7-diiodo-9,9-dimethylfluorene, etc. are obtained by synthesizing as follows. First, 1,5-diiodonaphthalene is obtained by converting the amino group contained in 1,5-diaminonaphthalene to a diazonium salt using sodium nitrite and concentrated sulfuric acid, and replacing it with iodine using potassium iodide. . In addition, 2,7-diiodo-9,9-dimethylfluorene is obtained by iodination of fluorene at positions 2 and 7 using orthoperiodic acid, followed by aqueous sodium hydroxide in dimethyl sulfoxide (abbreviation: DMSO), It can be obtained by dimethylation at the 9-position using benzyltrimethylammonium chloride or iodomethane.

  The anthracene derivative of the present invention as described above has resistance to repeated oxidation reactions. Moreover, it may be resistant to repeated oxidation reactions and may be resistant to repeated reduction reactions. Moreover, the anthracene derivative of the present invention described above can exhibit blue light emission. Therefore, it can be used as a light-emitting substance for manufacturing a blue light-emitting element. In addition, the anthracene derivative of the present invention described above has a large energy gap between the HOMO level and the LUMO level. Therefore, it can be used as a so-called host for making a light emitting substance exhibiting a red to blue emission color into a dispersed state. By using the anthracene derivative of the present invention as a light-emitting substance or host, a light-emitting element in which a change in host properties due to repeated oxidation reaction is small and an increase in driving voltage accompanying accumulation of light emission time is reduced is obtained. be able to.

(Embodiment 2)
An embodiment of a light-emitting element using the anthracene derivative of the present invention as a light-emitting substance is described with reference to FIGS.

  FIG. 1 shows a light-emitting element having a light-emitting layer 113 between the first electrode 101 and the second electrode 102. The light emitting layer 113 contains an anthracene derivative of the present invention represented by any one of the general formulas (1) to (8) and the structural formulas (1) to (40).

  In such a light-emitting element, holes injected from the first electrode 101 side and electrons injected from the second electrode 102 side recombine in the light-emitting layer 113 to excite the anthracene derivative of the present invention. Put it in a state. The excited anthracene derivative of the present invention emits light when returning to the ground state. Thus, the anthracene derivative of the present invention functions as a light emitting substance.

  Here, in the light-emitting layer 113, the anthracene derivative of the present invention represented by any one of the general formulas (1) to (8) and the structural formulas (1) to (40) has the anthracene derivative of the present invention. A layer dispersed and contained in a layer made of a substance having an energy gap larger than the energy gap is preferable. Accordingly, it is possible to prevent the light emission from the anthracene derivative of the present invention from being quenched due to the concentration. Note that the energy gap is an energy gap between the LUMO level and the HOMO level.

There is no particular limitation on a substance used for dispersing the anthracene derivative of the present invention, but anthracene derivatives such as 2-tert-butyl-9,10-di (2-naphthyl) anthracene (abbreviation: t-BuDNA) In addition to carbazole derivatives such as 4,4′-di (N-carbazolyl) biphenyl (abbreviation: CBP), bis [2- (2-hydroxyphenyl) pyridinato] zinc (abbreviation: Znpp ₂ ), bis [2- ( 2-hydroxyphenyl) benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ) and other metal complexes are preferable. One or two or more substances may be selected from these substances and mixed so that the anthracene derivative of the present invention is in a dispersed state. Such a layer in which a plurality of compounds are mixed can be formed by a co-evaporation method. Here, co-evaporation refers to a vapor deposition method in which raw materials are vaporized from a plurality of vapor deposition sources provided in one processing chamber, the vaporized raw materials are mixed in a gas phase state, and deposited on an object to be processed.

  There is no particular limitation on the first electrode 101 and the second electrode 102. Indium tin oxide (ITO), indium tin oxide containing silicon oxide, or indium oxide containing 2 to 20 wt% zinc oxide is used. In addition, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd ) Or the like. In addition to aluminum, an alloy of magnesium and silver, an alloy of aluminum and lithium, or the like can be used to form the first electrode 101. Note that there is no particular limitation on a method for forming the first electrode 101 and the second electrode 102, and the first electrode 101 and the second electrode 102 can be formed using, for example, a sputtering method or an evaporation method. Note that in order to extract the emitted light to the outside, one or both of the first electrode 101 and the second electrode 102 is made of indium tin oxide or the like, or silver, aluminum, or the like is several nm to several It is preferable to form the film so as to have a thickness of 10 nm so that visible light can be transmitted.

Further, a hole transport layer 112 may be provided between the first electrode 101 and the light emitting layer 113 as shown in FIG. Here, the hole transport layer is a layer having a function of transporting holes injected from the first electrode 101 side to the light-emitting layer 113. In this manner, by providing the hole transport layer 112, the distance between the first electrode 101 and the light-emitting layer 113 can be increased. As a result, due to the metal contained in the first electrode 101, It is possible to prevent the light emission from being quenched. The hole transport layer is preferably formed using a substance having a high hole transport property, and particularly preferably formed using a substance having a hole mobility of 1 × 10 ⁻⁶ cm ² / Vs or higher. Note that a substance having a high hole-transport property has a higher hole mobility than an electron, and the ratio of the hole mobility to the electron mobility (= hole mobility / electron mobility) is 100. Larger than the substance. Specific examples of a substance that can be used to form the hole-transport layer 112 include 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4, 4′-bis [N- (3-methylphenyl) -N-phenylamino] biphenyl (abbreviation: TPD), 4,4 ′, 4 ″ -tris (N, N-diphenylamino) triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 4,4′-bis {N- [4- ( N, N-di-m-tolylamino) phenyl] -N-phenylamino} biphenyl (abbreviation: DNTPD), 1,3,5-tris [N, N-di (m-tolyl) amino] benzene (abbreviation: m -MTDAB), 4,4 ', 4''- Squirrel (N- carbazolyl) triphenylamine (abbreviation: TCTA), phthalocyanine _{(abbreviation:} H 2 Pc), copper phthalocyanine (abbreviation: CuPc), or vanadyl phthalocyanine (abbreviation: VOPc), and the like. Further, the hole transport layer 112 may be a layer having a multilayer structure formed by combining two or more layers made of the substances described above.

Further, an electron transport layer 114 may be provided between the second electrode 102 and the light emitting layer 113 as shown in FIG. Here, the electron transporting layer is a layer having a function of transporting electrons injected from the second electrode 102 to the light emitting layer 113. In this manner, by providing the electron transport layer 114, the distance between the second electrode 102 and the light-emitting layer 113 can be increased, and as a result, light is emitted due to the metal contained in the second electrode 102. Can be prevented from quenching. The electron transport layer is preferably formed using a substance having a high electron transport property, and particularly preferably formed using a substance having an electron mobility of 1 × 10 ⁻⁶ cm ² / Vs or higher. Note that a substance having a high electron-transport property has higher electron mobility than holes, and the ratio of the electron mobility to the hole mobility (= electron mobility / hole mobility) is 100 or more. Also refers to a large substance. Specific examples of a substance that can be used for forming the electron-transport layer 114 include tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq _3). ), Bis (10-hydroxybenzo [h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), bis [2- In addition to metal complexes such as (2-hydroxyphenyl) benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ) 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (approximately) Name: PBD), 1,3-bis [5- (p-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4- tert-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 4,4-bis (5-methylbenzoxa) And sol-2-yl) stilbene (abbreviation: BzOs). Further, the electron transport layer 114 may be a multilayer structure formed by combining two or more layers made of the above-described substances.

Note that the hole transport layer 112 and the electron transport layer 114 may be formed using a bipolar substance in addition to the substances described above. A bipolar substance is the ratio of the mobility of one carrier to the mobility of the other carrier when the mobility of one of the electrons or holes is compared with the mobility of the other carrier. A substance whose value is 100 or less, preferably 10 or less. Examples of the bipolar substance include 2,3-bis (4-diphenylaminophenyl) quinoxaline (abbreviation: TPAQn). Among bipolar substances, it is particularly preferable to use a substance having a hole and electron mobility of 1 × 10 ⁻⁶ cm ² / Vs or more. Alternatively, the hole transport layer 112 and the electron transport layer 114 may be formed using the same bipolar substance.

Further, a hole injection layer 111 may be provided between the first electrode 101 and the hole transport layer 112 as shown in FIG. The hole injection layer 111 is a layer having a function of assisting injection of holes from the first electrode 101 to the hole transport layer 112. By providing the hole injection layer 111, the difference in ionization potential between the first electrode 101 and the hole transport layer 112 is reduced, and holes are easily injected. The hole injection layer 111 has a lower ionization potential than the substance forming the hole transport layer 112 and a higher ionization potential than the substance forming the first electrode 101, or the hole transport layer 112. It is preferable to use a substance whose energy band is bent when it is provided as a 1 to 2 nm thin film between the first electrode 101 and the first electrode 101. Specific examples of a substance that can be used to form the hole-injecting layer 111 include phthalocyanine-based compounds such as phthalocyanine (abbreviation: H ₂ Pc) and copper phthalocyanine (CuPc), or poly (ethylenedioxythiophene) / Examples thereof include a polymer such as a poly (styrenesulfonic acid) aqueous solution (PEDOT / PSS). That is, the hole injection layer 111 is selected by selecting a substance having a hole transporting property such that the ionization potential in the hole injection layer 111 is relatively smaller than the ionization potential in the hole transport layer 112. Can be formed. Note that in the case where the hole-injection layer 111 is provided, the first electrode 101 is preferably formed using a substance having a high work function such as indium tin oxide.

  Further, an electron injection layer 115 may be provided between the second electrode 102 and the electron transport layer 114 as shown in FIG. Here, the electron injection layer 115 is a layer having a function of assisting injection of electrons from the second electrode 102 to the electron transport layer 114. By providing the electron injection layer 115, the difference in electron affinity between the second electrode 102 and the electron transport layer 114 is reduced, and electrons are easily injected. The electron injection layer 115 is a substance having a higher electron affinity than the substance forming the electron transport layer 114 and a lower electron affinity than the substance forming the second electrode 102, or the electron transport layer 114 and the second transport layer 114. It is preferable to use a substance whose energy band is bent when it is provided as a 1 to 2 nm thin film between the electrode 102 and the electrode 102. Specific examples of a substance that can be used to form the electron injection layer 115 include alkali metal or alkaline earth metal, alkali metal fluoride, alkaline earth metal fluoride, alkali metal oxide, and alkaline earth. Examples thereof include inorganic substances such as metal oxides. In addition to inorganic substances, substances that can be used to form the electron transport layer 114 such as BPhen, BCP, p-EtTAZ, TAZ, and BzOs are also used for forming the electron transport layer 114 from these substances. By selecting a substance having a higher electron affinity than the substance, the substance can be used as a substance for forming the electron injection layer 115. That is, the electron injection layer 115 is formed by selecting a substance having an electron transporting property such that the electron affinity in the electron injection layer 115 is relatively larger than the electron affinity in the electron transport layer 114. Can do. Note that in the case where the electron injecting layer 115 is provided, the first electrode 101 is preferably formed using a substance having a low work function such as aluminum.

  In the light-emitting element of the present invention described above, the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, the electron transport layer 114, and the electron injection layer 115 are formed by an evaporation method, an inkjet method, or a coating method, respectively. Or any other method. Further, the first electrode 101 or the second electrode 102 may be formed by any method such as a sputtering method or an evaporation method.

  Further, a hole generation layer may be provided instead of the hole injection layer 111, or an electron generation layer may be provided instead of the electron injection layer 115.

  Here, the hole generation layer is a layer that generates holes. A hole generating layer can be formed by mixing a substance having a higher hole mobility than an electron and a substance having an electron accepting property with respect to a substance having a higher hole mobility than the electron. . Alternatively, the hole generating layer can be formed by mixing at least one substance selected from bipolar substances and a substance that exhibits an electron accepting property with respect to the bipolar substance. Here, as a substance having a higher mobility of holes than electrons, a substance similar to the substance that can be used to form the hole-transport layer 112 can be used. In addition, a bipolar substance such as TPAQn can be used as the bipolar substance. In addition, among substances having higher mobility of holes than electrons and bipolar substances, it is particularly preferable to use a substance containing triphenylamine in the skeleton. By using a substance containing triphenylamine in the skeleton, holes are more easily generated. As the substance exhibiting electron accepting properties, it is preferable to use a metal oxide such as molybdenum oxide, vanadium oxide, ruthenium oxide, or rhenium oxide.

The electron generating layer is a layer that generates electrons. An electron generating layer can be formed by mixing a substance having a higher electron mobility than a hole and a substance having an electron donating property with respect to a substance having a higher electron mobility than the hole. The electron generating layer can also be formed by mixing at least one substance selected from bipolar substances and a substance that exhibits an electron donating property with respect to the bipolar substance. Here, as a substance having higher electron mobility than holes, a substance similar to the substance that can be used to form the electron-transport layer 114 can be used. As for the bipolar substance, the bipolar substance described above such as TPAQn can be used. In addition, as a substance exhibiting electron donating property, a substance selected from alkali metals and alkaline earth metals, specifically lithium oxide (Li ₂ O), calcium oxide (CaO), sodium oxide ( At least one substance selected from Na ₂ O), potassium oxide (K ₂ O), magnesium oxide (MgO), and the like can also be used as the substance exhibiting electron donating properties. Further, an alkali metal fluoride, an alkaline earth metal fluoride, specifically, at least one substance selected from lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ₂ ), and the like is also an electron. It can be used as a substance exhibiting donating properties. Further, at least one substance selected from alkali metal nitride, alkaline earth metal nitride, and the like, specifically, calcium nitride, magnesium nitride, and the like can also be used as the substance exhibiting electron donating properties.

  Since the light-emitting element of the present invention having the above-described configuration uses the anthracene derivative of the present invention, there is little change in characteristics of the light-emitting element due to a change in the properties of the light-emitting substance due to repeated oxidation reactions, Stable light emission can be exhibited. In addition, since the light-emitting element of the present invention having the above-described structure uses the anthracene derivative of the present invention, it can emit light efficiently.

(Embodiment 3)
The anthracene derivative of the present invention can be contained in a light emitting layer together with a light emitting substance, and can be used as a so-called host for making the light emitting substance into a dispersed state. In this embodiment, an embodiment of a light-emitting element using the anthracene derivative of the present invention as a host will be described with reference to FIGS.

  FIG. 2 illustrates a light-emitting element having a light-emitting layer 213 between the first electrode 201 and the second electrode 202. A hole injection layer 211 and a hole transport layer 212 are provided between the first electrode 201 and the light emitting layer 213, and an electron transport layer 214 and an electron are disposed between the second electrode 202 and the light emitting layer 213. An injection layer 215 is provided. Note that there is no particular limitation on the stacked structure of the light-emitting element, and whether or not the hole injection layer 211, the hole transport layer 212, the electron transport layer 214, the electron injection layer 215, and other layers are provided. May be appropriately selected. As for the hole injection layer 211, the hole transport layer 212, the electron transport layer 214, and the electron injection layer 215, the hole injection layer 111, the hole transport layer 112, the electron transport layer 114, and the electron transport layer 114 described in Embodiment 2, respectively. Since the structure may be the same as that of the electron injection layer 115, description on these layers is omitted in this embodiment. Further, the first electrode 201 and the second electrode 202 may be the same as the first electrode 101 and the second electrode 102 described in Embodiment 1, respectively, and thus description thereof is omitted.

  In the light-emitting element of this embodiment mode, the light-emitting layer 213 contains the anthracene derivative of the present invention and a light-emitting substance having an emission spectrum peak in a band of 450 nm to 700 nm, preferably 480 nm to 600 nm. More specifically, the luminescent material is included so as to be dispersed in a layer comprising the anthracene derivative of the present invention. In this manner, by using a combination of these substances and the anthracene derivative of the present invention, a light-emitting element that can hardly extract light emitted from the host and can selectively extract light emitted from the light-emitting substance can be obtained. .

  Moreover, the anthracene derivative of the present invention is resistant to repeated oxidation reactions. Moreover, it may be resistant to repeated oxidation reactions and may be resistant to repeated reduction reactions. Therefore, in particular, in a light-emitting element that emits light when the host is excited and the generated excitation energy is transferred to the light-emitting substance, there is little change in the properties of the host due to repeated oxidation reactions, and the emission time is accumulated. A light-emitting element in which an increase in drive voltage accompanying the reduction is reduced can be obtained.

(Embodiment 4)
The light-emitting element of the present invention described in Embodiments 2 and 3 has resistance to repeated oxidation reactions (and may have resistance to repeated reduction reactions), and emits light in a good state for a long time. Therefore, by using the light-emitting element of the present invention, a light-emitting device that can provide a good display image or the like for a long period of time can be obtained.

  In this embodiment, a circuit configuration and a driving method of a light-emitting device having a display function will be described with reference to FIGS.

  FIG. 3 is a schematic view of a light emitting device to which the present invention is applied as viewed from above. In FIG. 3, a pixel portion 6511, a source signal line driver circuit 6512, a write gate signal line driver circuit 6513, and an erase gate signal line driver circuit 6514 are provided over a substrate 6500. The source signal line drive circuit 6512, the write gate signal line drive circuit 6513, and the erase gate signal line drive circuit 6514 are each an FPC (flexible printed circuit) 6503 which is an external input terminal via a wiring group. Connected. The source signal line driver circuit 6512, the writing gate signal line driver circuit 6513, and the erasing gate signal line driver circuit 6514 receive a video signal, a clock signal, a start signal, a reset signal, and the like from the FPC 6503, respectively. . A printed wiring board (PWB) 6504 is attached to the FPC 6503. Note that the driver circuit portion is not necessarily provided over the same substrate as the pixel portion 6511 as described above. For example, an IC chip mounted on an FPC on which a wiring pattern is formed (TCP) or the like is used. It may be used and provided outside the substrate.

  In the pixel portion 6511, a plurality of source signal lines extending in the column direction are arranged side by side in the row direction. In addition, current supply lines are arranged side by side in the row direction. In the pixel portion 6511, a plurality of gate signal lines extending in the row direction are arranged side by side in the column direction. In the pixel portion 6511, a plurality of sets of circuits including light-emitting elements are arranged.

  FIG. 4 is a diagram illustrating a circuit for operating one pixel. The circuit illustrated in FIG. 4 includes a first transistor 901, a second transistor 902, and a light emitting element 903.

  Each of the first transistor 901 and the second transistor 902 is a three-terminal element including a gate electrode, a drain region, and a source region, and has a channel region between the drain region and the source region. Here, since the source region and the drain region vary depending on the structure and operating conditions of the transistor, it is difficult to limit which is the source region or the drain region. Therefore, in this embodiment, regions functioning as a source or a drain are referred to as a first electrode and a second electrode, respectively.

  The gate signal line 911 and the writing gate signal line driving circuit 913 are provided so as to be electrically connected or disconnected by a switch 918. The gate signal line 911 and the erasing gate signal line driver circuit 914 are provided so as to be electrically connected or disconnected by a switch 919. The source signal line 912 is provided so as to be electrically connected to either the source signal line driver circuit 915 or the power source 916 by the switch 920. The gate of the first transistor 901 is electrically connected to the gate signal line 911. The first electrode of the first transistor is electrically connected to the source signal line 912, and the second electrode is electrically connected to the gate electrode of the second transistor 902. The first electrode of the second transistor 902 is electrically connected to the current supply line 917, and the second electrode is electrically connected to one electrode included in the light-emitting element 903. Note that the switch 918 may be included in the write gate signal line driver circuit 913. The switch 919 may also be included in the erase gate signal line driver circuit 914. Further, the switch 920 may also be included in the source signal line driver circuit 915.

  There is no particular limitation on the arrangement of transistors, light-emitting elements, and the like in the pixel portion, but they can be arranged as shown in the top view of FIG. In FIG. 5, the first electrode of the first transistor 1001 is connected to the source signal line 1004, and the second electrode is connected to the gate electrode of the second transistor 1002. The first electrode of the second transistor is connected to the current supply line 1005, and the second electrode is connected to the electrode 1006 of the light emitting element. Part of the gate signal line 1003 functions as a gate electrode of the first transistor 1001.

  Next, a driving method will be described. FIG. 6 is a diagram for explaining the operation of a frame over time. In FIG. 6, the horizontal direction represents the passage of time, and the vertical direction represents the number of scanning stages of the gate signal line.

  When image display is performed using the light emitting device of the present invention, the screen rewriting operation is repeatedly performed during the display period. The number of rewrites is not particularly limited, but is preferably at least about 60 times per second so that a person viewing the image does not feel flicker. Here, a period during which one screen (one frame) is rewritten is referred to as one frame period.

As shown in FIG. 6, one frame is time-divided into four subframes 501, 502, 503, and 504 including a writing period 501a, 502a, 503a, and 504a and a holding period 501b, 502b, 503b, and 504b. . A light emitting element to which a signal for emitting light is given is in a light emitting state in the holding period. The ratio of the length of the holding period in each subframe is as follows: first subframe 501: second subframe 502: third subframe 503: fourth subframe 504 = 2 ³ : 2 ² : 2 ¹ : 2 ⁰ = 8: 4: 2: 1. As a result, 4-bit gradation can be expressed. However, the number of bits and the number of gradations are not limited to those described here. For example, eight subframes may be provided so that 8-bit gradation can be performed.

  An operation in one frame will be described. First, in the subframe 501, the write operation is performed in order from the first row to the last row. Therefore, the start time of the writing period differs depending on the row. From the row in which the writing period 501a ends, the storage period 501b is started in order. In the holding period, the light-emitting element to which a signal for emitting light is given is in a light-emitting state. Further, the processing proceeds to the next subframe 502 in order from the row in which the holding period 501b ends, and the writing operation is performed in order from the first row to the last row as in the case of the subframe 501. The operation as described above is repeated until the holding period 504b of the subframe 504 ends. When the operation in the subframe 504 is completed, the process proceeds to the next frame. Thus, the accumulated time of the light emission in each subframe is the light emission time of each light emitting element in one frame. Various display colors having different brightness and chromaticity can be formed by changing the light emission time for each light emitting element and combining them in various ways within one pixel.

  When it is desired to forcibly end the holding period in the row that has already finished writing and has shifted to the holding period before the writing up to the last row is completed as in the subframe 504, after the holding period 504b. It is preferable to provide an erasing period 504c and control to forcibly enter a non-light emitting state. Then, the row that is forcibly set to the non-light-emitting state is kept in the non-light-emitting state for a certain period (this period is referred to as a non-light-emitting period 504d). Then, immediately after the writing period of the last row is completed, the writing period of the next subframe (or frame) is started in order from the first row. Accordingly, it is possible to prevent the writing period of the subframe 504 and the writing period of the next subframe from overlapping.

  In this embodiment, the subframes 501 to 504 are arranged in order from the longest holding period. However, the subframes 501 to 504 are not necessarily arranged as in the present embodiment. For example, the subframes 501 to 504 may be arranged in order from the shortest holding period. Alternatively, a long holding period and a short holding period may be arranged at random. In addition, the subframe may be further divided into a plurality of frames. That is, the gate signal line may be scanned a plurality of times during the period when the same video signal is applied.

  Here, the operation of the circuit shown in FIG. 4 in the writing period and the erasing period will be described.

  First, the operation in the writing period will be described. In the writing period, the gate signal line 911 in the n-th row (n is a natural number) is electrically connected to the writing gate signal line driving circuit 913 via the switch 918 and is connected to the erasing gate signal line driving circuit 914. Is disconnected. The source signal line 912 is electrically connected to the source signal line driver circuit through the switch 920. Here, a signal is input to the gate of the first transistor 901 connected to the gate signal line 911 in the n-th row (n is a natural number), and the first transistor 901 is turned on. At this time, video signals are simultaneously input to the source signal lines from the first column to the last column. Note that the video signals input from the source signal lines 912 in each column are independent from each other. A video signal input from the source signal line 912 is input to the gate electrode of the second transistor 902 through the first transistor 901 connected to each source signal line. At this time, a current value supplied from the current supply line 917 to the light-emitting element 903 is determined by a signal input to the second transistor 902. Then, depending on the current value, the light emitting element 903 determines light emission or non-light emission. For example, in the case where the second transistor 902 is a p-channel transistor, the light-emitting element 903 emits light by inputting a low level signal to the gate electrode of the second transistor 902. On the other hand, in the case where the second transistor 902 is an n-channel transistor, the light-emitting element 903 emits light when a high level signal is input to the gate electrode of the second transistor 902.

  Next, the operation in the erasing period will be described. In the erasing period, the gate signal line 911 in the n-th row (n is a natural number) is electrically connected to the erasing gate signal line driving circuit 914 via the switch 919, and is connected to the writing gate signal line driving circuit 913. Not connected. The source signal line 912 is electrically connected to the power source 916 through the switch 920. Here, a signal is input to the gate of the first transistor 901 connected to the gate signal line 911 in the n-th row, and the first transistor 901 is turned on. At this time, the erase signal is simultaneously input to the source signal lines from the first column to the last column. The erase signal input from the source signal line 912 is input to the gate electrode of the second transistor 902 through the first transistor 901 connected to each source signal line. At this time, current supplied from the current supply line 917 to the light-emitting element 903 is blocked by a signal input to the second transistor 902. Then, the light emitting element 903 is forced to emit no light. For example, in the case where the second transistor 902 is a p-channel transistor, the light-emitting element 903 does not emit light when a high level signal is input to the gate electrode of the second transistor 902. On the other hand, in the case where the second transistor 902 is an n-channel transistor, the light emitting element 903 does not emit light by inputting a low level signal to the gate electrode of the second transistor 902.

  In the erasing period, for the nth row (n is a natural number), a signal for erasing is input by the operation as described above. However, as described above, the nth row may be an erasing period and the other row (mth row (m is a natural number)) may be a writing period. In such a case, it is necessary to input a signal for erasure to the n-th row and a signal for writing to the m-th row using the source signal line in the same column. It is preferable to operate as described above.

  The gate signal line 911 and the erasing gate signal line driving circuit 914 are immediately disconnected after the light emitting element 903 in the n-th row does not emit light by the operation in the erasing period described above. The switch 920 is switched to connect the source signal line 912 and the source signal line driver circuit 915. Then, the source signal line and the source signal line driver circuit 915 are connected, and the gate signal line 911 and the writing gate signal line driver circuit 913 are connected. Then, a signal is selectively input from the writing gate signal line driving circuit 913 to the m-th signal line, the first transistor is turned on, and the source signal line driving circuit 915 receives the final signal from the first column. A signal for writing is input to the source signal lines up to the column. By this signal, the m-th row light emitting element emits light or does not emit light.

Immediately after the writing period for the m-th row is completed as described above, the erasing period for the (n + 1) -th row is started. For this purpose, the gate signal line 911 and the writing gate signal line driving circuit 913 are disconnected, and the switch 920 is switched to connect the source signal line to the power source 916. Further, the gate signal line 911 and the writing gate signal line driving circuit 913 are disconnected, and the gate signal line 911 is connected to the erasing gate signal line driving circuit 914. Then, a signal is selectively input from the erasing gate signal line driving circuit 914 to the gate signal line of the (n + 1) th row to turn on the signal to the first transistor, and an erasing signal is input from the power supply 916. In this way, immediately after the erasing period of the (n + 1) th row is completed, the writing period of the (m + 1) th row is started. Thereafter, similarly, the erasing period and the writing period may be repeated until the erasing period of the last row is operated.

  In this embodiment, the mode in which the m-th writing period is provided between the n-th erasing period and the (n + 1) -th erasing period has been described. An m-th writing period may be provided between the period and the n-th erasing period.

  In this embodiment, when the non-light emission period 504d is provided as in the subframe 504, the erasing gate signal line driver circuit 914 and one gate signal line are disconnected from each other, and the write gate The operation of connecting the signal line driver circuit 913 and the other gate signal lines is repeated. Such an operation may be performed particularly in a frame in which a non-light emitting period is not provided.

(Embodiment 5)
A circuit having a function of controlling light emission and non-light emission of the light emitting element is not necessarily limited to that shown in FIG. For example, a circuit as shown in FIG. 7 may be used.

  In FIG. 7, a first transistor 2101, a second transistor 2103, an erasing diode 2111, and a light emitting element 2104 are arranged. The source and drain of the first transistor 2101 are connected to the signal line 2105 and the gate of the second transistor 2103, respectively. The gate of the first transistor 2101 is connected to the first gate line 2107. The source and the drain of the second transistor 2103 are connected to the power supply line 2106 and the light-emitting element 2104, respectively. The erasing diode 2111 is connected to the gate of the second transistor 2103 and the second gate line 2117.

  The storage capacitor 2102 has a function of holding the gate potential of the second transistor 2103. Therefore, although connected between the gate of the second transistor 2103 and the power supply line 2106, the position where the storage capacitor 2102 is provided is not limited thereto. It is only necessary that the gate potential of the second transistor 2103 be held. In the case where the gate potential of the second transistor 2103 can be held using the gate capacitance of the second transistor 2103 or the like, the storage capacitor 2102 may be omitted.

  As an operation method, the first gate line 2107 is selected, the first transistor 2101 is turned on, and a signal is input from the signal line 2105 to the storage capacitor 2102. Then, the current of the second transistor 2103 is controlled in accordance with the signal, and current flows from the first power supply line 2106 through the light emitting element 2104 to the second power supply line 2108.

  When the signal is to be erased, the second gate line 2117 is selected (here, set to a high potential), the erasing diode 2111 is turned on, and a current flows from the second gate line 2117 to the gate of the second transistor 2103. Make it flow. As a result, the second transistor 2103 is turned off. Then, no current flows from the first power supply line 2106 to the second power supply line 2108 through the light emitting element 2104. As a result, a non-lighting period can be created and the length of the lighting period can be freely controlled.

  When it is desired to hold the signal, the second gate line 2117 is not selected (here, set to a low potential). Then, the erasing diode 2111 is turned off, so that the gate potential of the second transistor 2103 is held.

  The erasing diode 2111 may be anything as long as it has a rectifying property. A PN-type diode, a PIN-type diode, a Schottky diode, or a Zener-type diode may be used.

  Alternatively, a transistor may be used by diode connection (gate and drain connected). A P-channel type may be used.

(Embodiment 6)
One mode of a cross-sectional view of a light-emitting device including the light-emitting element of the present invention is described with reference to FIGS.

  In FIG. 8, a transistor 11 provided for driving the light emitting element 12 of the present invention is surrounded by a dotted line. The light emitting element 12 is the light emitting element of the present invention having the light emitting layer 15 between the first electrode 13 and the second electrode 14. The drain of the transistor 11 and the first electrode 13 are electrically connected by a wiring 17 penetrating the first interlayer insulating films 16a, 16b, and 16c. The light emitting element 12 is separated from another light emitting element provided adjacent thereto by a partition wall layer 18. The light-emitting device of the present invention having such a structure is provided over the substrate 10 in this embodiment.

  Note that the transistor 11 illustrated in FIG. 8 is a top-gate transistor in which a gate electrode is provided on the opposite side of the substrate with a semiconductor layer as a center. However, the structure of the transistor 11 is not particularly limited, and may be, for example, a bottom gate type. In the case of a bottom gate, the semiconductor layer forming a channel may be formed with a protective film (channel protection type), or the semiconductor layer forming the channel may be partially concave ( Channel etch type).

  Further, the semiconductor layer included in the transistor 11 may be either crystalline or non-crystalline. Moreover, a semi-amorphous etc. may be sufficient.

The semi-amorphous semiconductor is as follows. A semiconductor having an intermediate structure between amorphous and crystalline (including single crystal and polycrystal) and having a third state that is stable in terms of free energy, has a short-range order, and has a lattice distortion. It contains a crystalline region. Further, at least a part of the region in the film contains crystal grains of 0.5 to 20 nm. The Raman spectrum is shifted to the lower wavenumber side than 520 cm ⁻¹ . In X-ray diffraction, diffraction peaks of (111) and (220) that are derived from the Si crystal lattice are observed. In order to terminate dangling bonds (dangling bonds), hydrogen or halogen is contained at least 1 atomic% or more. It is also called a so-called microcrystalline semiconductor (microcrystal semiconductor). It is formed by glow discharge decomposition (plasma CVD) of a gas such as SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , or SiF ₄ . These gases may be diluted with H ₂ , or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, and Ne. The dilution rate is in the range of 2 to 1000 times. The pressure is generally in the range of 0.1 Pa to 133 Pa, and the power supply frequency is 1 MHz to 120 MHz, preferably 13 MHz to 60 MHz. The substrate heating temperature may be 300 ° C. or less, preferably 100 to 250 ° C. As an impurity element in the film, impurities of atmospheric components such as oxygen, nitrogen, and carbon are desirably 1 × 10 ²⁰ / cm ³ or less, In particular, the oxygen concentration is 5 × 10 ¹⁹ / cm ³ or less, preferably 1 × 10 ¹⁹ / cm ³ or less.

  Further, specific examples of the crystalline semiconductor layer include those made of single crystal or polycrystalline silicon, silicon germanium, or the like. These may be formed by laser crystallization, or may be formed by crystallization by a solid phase growth method using nickel or the like, for example.

  Note that in the case where the semiconductor layer is formed of an amorphous material, for example, amorphous silicon, the transistor 11 and other transistors (transistors constituting a circuit for driving a light emitting element) are all configured by N-channel transistors. It is preferable that the light-emitting device have a structured circuit. Other than that, a light-emitting device having a circuit including any one of an N-channel transistor and a P-channel transistor, or a light-emitting device including a circuit including both transistors may be used.

  Further, the first interlayer insulating film 16 may be a multilayer as shown in FIGS. 8A and 8C, or may be a single layer. The first interlayer insulating film 16a is made of an inorganic material such as silicon oxide or silicon nitride, and the first interlayer insulating film 16b has a skeleton structure formed of a bond of acrylic or siloxane (silicon (Si) and oxygen (O). , Hydrogen, or a compound having an organic group such as an alkyl group as a substituent), and a self-flattening material such as silicon oxide that can be coated and formed. Further, the first interlayer insulating film 16c is made of a silicon nitride film containing argon (Ar). In addition, there is no limitation in particular about the substance which comprises each layer, You may use things other than what was described here. Moreover, you may further combine the layer which consists of substances other than these. As described above, the first interlayer insulating films 16a, 16b, and 16c may be formed using both an inorganic material and an organic material, or may be formed of any one of an inorganic film and an organic film.

  The partition layer 18 preferably has a shape in which the radius of curvature continuously changes at the edge portion. The partition layer 18 is formed using acrylic, siloxane, resist, silicon oxide, or the like. The partition wall layer 18 may be formed of any one of an inorganic film and an organic film, or may be formed using both.

  8A and 8C, only the first interlayer insulating films 16a, 16b, and 16c are provided between the transistor 11 and the light emitting element 12, but as shown in FIG. 8B. In addition to the first interlayer insulating film 16 (16a, 16b), the second interlayer insulating film 19 may be provided. In the light emitting device shown in FIG. 8B, the first electrode 13 penetrates through the second interlayer insulating film 19 and is connected to the wiring 17.

  Similar to the first interlayer insulating film 16, the second interlayer insulating films 19a and 19b may be a multilayer or a single layer. The second interlayer insulating film 19a is made of a material having self-flatness such as acrylic, siloxane, or silicon oxide that can be coated. Further, the second interlayer insulating film 19b is made of a silicon nitride film containing argon (Ar). In addition, there is no limitation in particular about the substance which comprises each layer, You may use things other than what was described here. Moreover, you may further combine the layer which consists of substances other than these. As described above, the second interlayer insulating films 19a and 19b may be formed using both inorganic or organic materials, or may be formed of any one of an inorganic film and an organic film.

  In the light-emitting element 12, when each of the first electrode and the second electrode is formed using a light-transmitting substance, the first electrode and the second electrode are represented by the white arrows in FIG. Light emission can be extracted from both the electrode 13 side and the second electrode 14 side. In addition, in the case where only the second electrode 14 is formed using a light-transmitting substance, light emission is extracted only from the second electrode 14 side as represented by a white arrow in FIG. 8B. be able to. In this case, it is preferable that the first electrode 13 is made of a material having a high reflectivity, or a film (reflective film) made of a material having a high reflectivity is provided below the first electrode 13. In addition, in the case where only the first electrode 13 is formed using a light-transmitting substance, light emission is extracted only from the first electrode 13 side as represented by a white arrow in FIG. 8C. be able to. In this case, it is preferable that the second electrode 14 is made of a highly reflective material, or a reflective film is provided above the second electrode 14.

  The light-emitting element 12 may have a configuration in which the first electrode 13 functions as an anode and the second electrode 14 functions as a cathode, or the first electrode 13 functions as a cathode, and the second The electrode 14 may function as an anode. However, in the former case, the transistor 11 is a P-channel transistor, and in the latter case, the transistor 11 is an N-channel transistor.

(Embodiment 7)
Note that as described in Embodiments 4 to 6, the light-emitting element of the present invention may be used as a pixel of an active matrix light-emitting device that is connected to a transistor and emits light or does not emit light in response to a signal from the transistor. Alternatively, as shown in FIG. 46, a passive light-emitting device that drives a light-emitting element without particularly providing a driving element such as a transistor may be used.

  FIG. 46 is a perspective view of a passive light-emitting device manufactured by applying the present invention. In FIG. 46, an electrode 1902 and an electrode 1906 are provided between a substrate 1901 and a substrate 1907. The electrode 1902 and the electrode 1906 are provided so as to intersect. Further, a light emitting layer 1905 (indicated by a broken line so that the arrangement of 1902, 1904, etc. can be seen) is provided between the electrode 1902 and the electrode 1906. Note that a hole-transport layer, an electron-transport layer, or the like may be provided between the light-emitting layer 1905 and the electrode 1902 or between the light-emitting layer 1905 and the electrode 1906. A partition wall layer 1904 is provided at an end portion of the electrode 1902. In this manner, the barrier rib layer 1904 is covered. A passive light emitting device can also be driven with low power consumption by including the light emitting element of the present invention that operates at a low driving voltage.

(Embodiment 8)
By mounting the light-emitting device of the present invention, an excellent electronic display can be performed over a long period of time, and an electronic device with less misidentification of information due to display image disturbance can be obtained.

  One mode of an electronic device mounted with a light-emitting device to which the present invention is applied is shown in FIG.

  FIG. 9A illustrates a laptop personal computer manufactured by applying the present invention, which includes a main body 5521, a housing 5522, a display portion 5523, a keyboard 5524, and the like. A personal computer can be completed by incorporating a light-emitting device having the light-emitting element of the present invention as a display portion.

  FIG. 9B illustrates a cellular phone manufactured by applying the present invention, which includes a main body 5552 which includes a display portion 5551, an audio output portion 5554, an audio input portion 5555, operation switches 5556 and 5557, an antenna 5553, and the like. Has been. A telephone can be completed by incorporating a light-emitting device having the light-emitting element of the present invention as a display portion.

  FIG. 9C illustrates a television set manufactured by applying the present invention, which includes a display portion 5531, a housing 5532, a speaker 5533, and the like. A television receiver can be completed by incorporating a light-emitting device having the light-emitting element of the present invention as a display portion.

  As described above, the light-emitting device of the present invention is suitable for use as a display portion of various electronic devices.

  Note that although a laptop personal computer is described in this embodiment mode, a light-emitting device including the light-emitting element of the present invention may be mounted on a mobile phone, a car navigation device, a camera, a lighting device, or the like. .

(Synthesis Example 1)
In this synthesis example, a method for synthesizing an anthracene represented by the structural formula (1) will be described.
[Step 1]
A method for synthesizing 9,10-bis (4-bromophenyl) -2-tert-butylanthracene will be described.

  Under a nitrogen stream, a 1.58 mol / L butyllithium hexane solution (13.4 mL) was added dropwise to a dry ether solution (200 mL) containing 5.0 g of 1,4-dibromobenzene at −78 ° C. After completion of dropping, the mixture was stirred at the same temperature for 1 hour. A dry ether solution (40 mL) of 2-tert-butylanthraquinone (2.80 g) was added dropwise at −78 ° C., and then the reaction solution was slowly warmed to room temperature. After stirring at room temperature overnight, water was added and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over magnesium sulfate, filtered and concentrated, and the residue was purified by silica gel chromatography (developing solvent, hexane-ethyl acetate) to obtain the compound at a weight of 5.5 g.

The obtained compound was measured by a nuclear magnetic resonance method ( ¹ H-NMR) and found to be 9,10-bis (4-bromophenyl) -2-tert-butyl-9,10-dihydroxy-9,10-dihydroanthracene. It was confirmed that.

¹ H-NMR of this compound is shown below.
¹ H-NMR (300 MHz, CDCl ₃ ): δ = 1.31 (s, 9H), 2.81 (s, 1H), 2.86 (s, 1H), 6.82-6.86 (m, 4H), 7.13-7.16 (m, 4H), 7.36-7.43 (m, 3H), 7.53-7.70 (m, 4H)

  In addition, a synthesis scheme (b-1) of 9,10-bis (4-bromophenyl) -2-tert-butyl-9,10-dihydroxy-9,10-dihydroanthracene is shown below.

987 mg (1.55 mmol) of 9,10-bis (4-bromophenyl) -2-tert-butyl-9,10-dihydroxy-9,10-dihydroanthracene synthesized as described above under the atmosphere, potassium iodide 664 mg (4 mmol) and 1.48 g (14 mmol) of sodium phosphinate monohydrate were suspended in 12 mL of glacial acetic acid and stirred under reflux for 2 hours. After cooling to room temperature, the resulting precipitate was filtered and washed with about 50 mL of methanol to obtain a filtrate. Then, the filtrate was dried to obtain 700 mg of a cream powder compound. The yield was 82%. When this compound was measured by a nuclear magnetic resonance method ( ¹ H-NMR, ¹³ C-NMR), it was confirmed to be 9,10-bis (4-bromophenyl) -2-tert-butylanthracene.

¹ H-NMR and ¹³ C-NMR of this compound are shown below.
¹ H-NMR (300 MHz, CDCl ₃ ): δ = 1.28 (s, 9H), 7.25-7.37 (m, 6H), 7.44-7.48 (m, 1H) 7.56 -7.65 (m, 4H), 7.71-7.76 (m, 4H)
¹³ C-NMR (74 MHz, CDCl ₃ ): δ = 30.8, 35.0, 120.8, 121.7, 121.7, 124.9, 125.0, 125.2, 126.4, 126 .6, 126.6, 128.3, 129.4, 129.7, 129.9, 131.6, 131.6, 133.0, 133.0, 135.5, 135.7, 138.0 138.1, 147.8

  In addition, a synthesis scheme (b-2) of 9,10-bis (4-bromophenyl) -2-tert-butylanthracene is shown below.

[Step 2]
A method for synthesizing 3- (N-phenylamino) -9-phenylcarbazole will be described.

  First, 24.3 g (100 mmol) of N-phenylcarbazole was dissolved in 600 mL of glacial acetic acid, 17.8 g (100 mmol) of N-bromosuccinimide was slowly added, and the mixture was stirred overnight at room temperature. This glacial acetic acid solution was added dropwise to 1 L of ice water with stirring. The precipitated white solid was washed 3 times with water. This solid was dissolved in 150 mL of diethyl ether and washed with a saturated aqueous sodium hydrogen carbonate solution and water. This organic layer was dried over magnesium sulfate. This was filtered and the resulting filtrate was concentrated. About 50 mL of methanol was added to the obtained residue, and ultrasonic waves were applied to dissolve the residue uniformly. This solution was allowed to stand to precipitate a white solid. This was filtered and the residue was dried to obtain 28.4 g (yield 88%) of 3-bromo-9-phenylcarbazole as a white powder.

  A synthesis scheme (c-1) of 3-bromo-9-phenylcarbazole is shown below.

Next, under nitrogen, 19 g (60 mmol) of 3-bromo-9-phenylcarbazole, 340 mg (0.6 mmol) of bisdibenzylideneacetone palladium (0) (abbreviation: Pd (dba) ₂ ), 1,1-bis ( To a mixture of 1.6 g (3.0 mmol) of diphenylphosphino) ferrocene (abbreviation: DPPF) and 13 g (180 mmol) of sodium-tert-butoxide (abbreviation: tBuONa) was added 110 mL of dehydrated xylene and 7.0 g (75 mmol) of aniline. It was. This was heated and stirred at 90 ° C. for 7.5 hours in a nitrogen atmosphere. After completion of the reaction, about 500 mL of toluene warmed to 50 ° C. was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated, hexane-ethyl acetate was added to the residue, and ultrasonic waves were applied. The obtained suspension was filtered, and the residue was dried to obtain 15 g of a cream-colored powder (yield 75%). It was confirmed by nuclear magnetic resonance ( ¹ H-NMR) that this cream-colored powder was 3- (N-phenylamino) -9-phenylcarbazole (abbreviation: PCA).

¹ H-NMR of this compound is shown below. In addition, the ¹ H-NMR chart is shown in FIGS. Note that FIG. 13B is a chart in which the range of 5 ppm to 9 ppm in FIG.
¹ H NMR (300 MHz, CDCl ₃ ); δ = 6.84 (t, j = 6.9, 1H), 6.97 (d, j = 7.8, 2H), 7.20-7.61 ( m, 13H), 7.90 (s, 1H), 8.04 (d, j = 7.8, 1H)

  A synthesis scheme (c-2) of 3- (N-phenylamino) -9-phenylcarbazole is shown below.

[Step 3]
A method for synthesizing 9,10-bis {4- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] phenyl} -2-tert-butylanthracene (abbreviation: PCABPA) will be described.

Under nitrogen, 540 mg (1.0 mmol) of 9,10-bis (4-bromophenyl) -2-tert-butylanthracene, 670 mg (2.0 mmol) of 3- (N-phenylamino) -9-phenylcarbazole, bis (Dibenzylideneacetone) palladium (0) 12 mg (0.02 mmol), 1,1-bis (diphenylphosphino) ferrocene 110 mg (0.2 mmol), sodium-tert-butoxide 600 mg (6.2 mmol) 10 mL was added. This was heated and stirred at 90 ° C. for 5 hours in a nitrogen atmosphere. After completion of the reaction, about 100 mL of toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated and fractionated by silica gel column chromatography (toluene: hexane = 1: 1). This was concentrated, and the obtained residue was recrystallized from dichloromethane-hexane. In this way, 500 mg of yellowish green powder was obtained (yield 48%). This yellow-green powder was converted into 9,10-bis {4- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] phenyl} -2-tert by nuclear magnetic resonance ( ¹ H-NMR). -It was confirmed that it was butylanthracene (abbreviation: PCABPA).

¹ H-NMR of this compound is shown below. In addition, ¹ H-NMR charts are shown in FIGS. Note that FIG. 14B is a chart in which the range of 6.5 ppm to 8.5 ppm in FIG.
¹ H NMR (300 MHz, DMSO-d): δ = 3.33 (s, 9H), 6.98-7.79 (m, 44H), 8.16-8.27 (m, 4H)

  Further, a synthesis scheme (d-1) of PCABPA is shown below.

  Moreover, the absorption spectrum of PCABPA is shown in FIG. In FIG. 10, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). Moreover, (a) is an absorption spectrum in a single film state, and (b) is an absorption spectrum in a state dissolved in a toluene solution. The emission spectrum of PCABPA is shown in FIG. In FIG. 11, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). Further, (a) is an emission spectrum (excitation wavelength 352 nm) in a single film state, and (b) is an emission spectrum (excitation wavelength 390 nm) in a state dissolved in a toluene solution. From FIG. 11, it can be seen that the emission from PCABPA has a peak at 488 nm in the single film state and a peak at 472 nm in the toluene solution. These luminescences were visually recognized as blue luminescent colors.

  Moreover, when the obtained PCABPA was formed into a film by a vapor deposition method and the ionization potential of the compound in a thin film state was measured using a photoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd.), it was 5.31 eV. . Further, the absorption spectrum of the compound in a thin film state is measured using a UV / visible light spectrophotometer (manufactured by JASCO Corporation, V-550), and the wavelength of the absorption edge on the long wavelength side of the absorption spectrum is expressed as an energy gap ( 2.77 eV) and the LUMO level was determined. The LUMO level was -2.54 eV.

Furthermore, when the decomposition temperature T _d of the obtained PCABPA was measured by a thermothermographic simultaneous measurement apparatus (Seiko Denshi Co., Ltd., TG / DTA 320 type), T _d = 485 ° C. and good heat resistance was obtained. I found out that

  Moreover, the oxidation reaction characteristic and reduction reaction characteristic of PCABPA were investigated by cyclic voltammetry (CV) measurement. For the measurement, an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model 600A) was used.

The solution in the CV measurement uses dehydrated dimethylformamide (DMF) as a solvent and dissolves the supporting electrolyte tetra-n-butylammonium perchlorate (n-Bu ₄ NClO ₄ ) to a concentration of 100 mmol / L. Further, PCABPA as a measurement target was prepared by dissolving it to a concentration of 1 mmol / L. In addition, as a working electrode, a platinum electrode (manufactured by BAS Co., Ltd., PTE platinum electrode), and as an auxiliary electrode, a platinum electrode (manufactured by BAS Inc., Pt counter electrode for VC-3 ( 5 cm)), and an Ag / Ag ⁺ electrode (manufactured by BAS Co., Ltd., RE5 nonaqueous solvent system reference electrode) was used as a reference electrode.

The oxidation reaction characteristics were examined as follows.
A scan in which the potential of the working electrode with respect to the reference electrode was changed from −0.01 to 0.6 V and then changed from 0.6 V to −0.01 V was taken as one cycle, and 100 cycles were measured. The scan speed for CV measurement was set to 0.1 V / s.

The reduction reaction characteristics were examined as follows.
A scan in which the potential of the working electrode with respect to the reference electrode was changed from −0.9 to −2.7 V and then changed from −2.7 V to −0.9 V was set as one cycle, and 100 cycles were measured. The scan speed for CV measurement was set to 0.1 V / s.

The results of examining the oxidation reaction characteristics of PCABPA are shown in FIG. In addition, FIG. 12B shows the results of examining the reduction reaction characteristics of PCABPA. 12A and 12B, the horizontal axis represents the potential (V) of the working electrode with respect to the reference electrode, and the vertical axis represents the current value (1 × 10 ⁻⁵ A) flowing between the working electrode and the auxiliary electrode. ).

From FIG. 12A, it was found that the oxidation potential was 0.42 V (vs. Ag / Ag ⁺ electrode). Further, from FIG. 12B, it was found that the reduction potential was −2.39 V (vs. Ag / Ag ⁺ electrode). In addition, despite the repetition of scanning for 100 cycles, there is almost no change in the peak position or peak intensity of the CV curve for both the oxidation reaction and the reduction reaction. From this, it was found that PCABPA, which is one of the compounds of the present invention, is extremely stable against repeated oxidation reactions. Furthermore, it was found that it is extremely stable against repeated reduction reactions.

(Synthesis Example 2)
In this synthesis example, 9,10-bis {4 ′-[N- (9-phenylcarbazol-3-yl) -N-phenylamino] biphenyl-4-yl which is an anthracene derivative represented by the structural formula (13) } A synthesis method of 2-tert-butylanthracene (abbreviation: PCABBA) will be described.
[Step 1]
First, a method for synthesizing 9,10-bis (4′-bromobiphenyl-4-yl) -2-tert-butylanthracene will be described.

6.54 g (21.0 mmol) of 4,4′-dibromobiphenyl was placed in a 500 mL three-necked flask and purged with nitrogen, and 200 mL of tetrahydrofuran was added. Solution) 14.5 mL (22.3 mmol) was added dropwise, and the mixture was stirred for 1 hour while maintaining at −80 ° C. While maintaining at −80 ° C., a mixed solution in which 2.07 g (10.0 mmol) of anthraquinone was suspended in 20 mL of tetrahydrofuran (abbreviation: THF) was added dropwise to the reaction solution, and after completion of the addition, the temperature was returned from −80 ° C. to room temperature. The mixture was further stirred for 2 hours. After the reaction, 110 mL of ethanol was added and stirred, and then the reaction solution was washed with water and saturated brine, and dried over magnesium sulfate. The reaction mixture was naturally filtered, and the filtrate was concentrated to obtain a pale yellow solid (Synthesis scheme (e-1)).

  The obtained pale yellow solid, 6.64 g (40 mmol) of potassium iodide, 12.7 g (120 mmol) of sodium phosphinate monohydrate, and 120 mL of glacial acetic acid were placed in a flask having a capacity of 500 mL and refluxed for 2 hours. After the reaction, the solid precipitated after cooling to room temperature was collected by suction filtration and recrystallized from dichloromethane / ethanol to obtain the desired product, 9,10-bis (4′-bromobiphenyl-4-yl) -2-tert. -3.43 g of a light yellow solid of butylanthracene was obtained in a yield of 51% (synthesis scheme (e-2)).

  In addition, synthesis schemes (e-1) and (e-2) of Step 1 are shown below.

[Step 2]
Next, 9,10-bis {4 ′-[N- (9-phenylcarbazol-3-yl) -N-phenylamino] biphenyl-4-yl} -2-tert represented by the structural formula (13) A method for synthesizing butylanthracene will be described.

  In a three-necked flask, 700 mg (1.0 mmol) of 9,10-bis (4′-bromobiphenyl-4-yl) -2-tert-butylanthracene obtained in Step 1 of this Synthesis Example, Step 2 of Synthesis Example 1 3- (N-phenylamino) -9-phenylcarbazole (abbreviation: PCA) obtained in 670 mg (2.0 mmol), bis (dibenzylideneacetone) palladium (0) 60 mg (0.10 mmol), tri-tert -1.0 mL (0.50 mmol) of butylphosphine (10 wt% hexane solution) and 0.4 g (4.0 mmol) of sodium tert-butoxide were added, 10 mL of dehydrated xylene was added, and nitrogen substitution was performed. This was stirred with heating at 120 ° C. for 6 hours under a nitrogen atmosphere. After completion of the reaction, about 200 mL of toluene was added to this suspension, and this was filtered through Florisil and Celite. The obtained filtrate was concentrated and fractionated by silica gel column chromatography (toluene: hexane = 1: 1). This was concentrated, hexane was added to the resulting residue and recrystallized by irradiating with ultrasonic waves, and 9,10-bis {4 ′-[N- (9-phenylcarbazol-3-yl) which was the target product. ) -N-phenylamino] biphenyl-4-yl} -2-tert-butylanthracene (abbreviation: PCABBA) beige powder was obtained in an amount of 70 mg in a yield of 6%.

  Further, the synthesis scheme (f-1) of Step 2 is shown below.

Below, the analysis result of < ¹ > H-NMR is shown below. ¹ H-NMR charts are shown in FIGS. Note that FIG. 47B is a chart in which the range of 9 ppm to 6 ppm in FIG.

¹ H-NMR (300 MHz, DMSO-d): δ = 1.22 (s, 9H), 7.04 (t, J = 6.9 Hz, 2H), 7.14-7.79 (m, 39H) 7.88-7.94 (m, 4H), 8.12 (d, J = 1.5 Hz, 2H), 8.20 (d, J = 8.4 Hz, 2H)

  Further, FIG. 48 shows an absorption spectrum of PCABBA in a toluene solution. In FIG. 48, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). Further, FIG. 49 shows an emission spectrum of the PCABBA in the toluene solution. In FIG. 49, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). From FIG. 49, it was found that the light emission from PCABBA had a peak at 445 nm in the toluene solution, which was visually recognized as blue light emission. Therefore, it was found that PCABBA is a substance suitable as a light-emitting substance that emits blue light.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, after evacuating the vacuum apparatus and reducing the pressure to 1 × 10 ⁻⁴ Pa, a first layer 303 made of copper phthalocyanine was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 20 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 40 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing t-BuDNA and PCABPA was formed on the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of t-BuDNA to PCABPA was 1: 0.05 = t-BuDNA: PCABPA. As a result, PCABPA is in a state of being dispersed in a layer made of t-BuDNA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 20 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

  Next, a fifth layer 307 made of calcium fluoride was formed on the fourth layer 306 by an evaporation method. The thickness of the fifth layer 307 was set to 1 nm. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 16 shows the result of examining the voltage-luminance characteristic, and FIG. 17 shows the result of examining the luminance-current efficiency characteristic. In FIG. 16, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 17, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  FIG. 18 shows an emission spectrum of the light-emitting element manufactured in this example. In FIG. 18, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). From FIG. 18, it was found that the light-emitting element of this example had a peak of emission spectrum at 477 nm and exhibited blue light emission. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.16, 0.28), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, after evacuating the vacuum apparatus and reducing the pressure to 1 × 10 ⁻⁴ Pa, a first layer 303 made of copper phthalocyanine was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 20 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 including 4,4′-bis [N- (4-biphenylyl) -N-phenylamino] biphenyl (abbreviation: BBPB) is formed over the first layer 303 by an evaporation method. did. The thickness of the second layer 304 was set to 40 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing t-BuDNA and PCABPA was formed on the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of t-BuDNA to PCABPA was 1: 0.05 = t-BuDNA: PCABPA. As a result, PCABPA is in a state of being dispersed in a layer made of t-BuDNA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 20 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

  Next, a fifth layer 307 made of calcium fluoride was formed on the fourth layer 306 by an evaporation method. The thickness of the fifth layer 307 was set to 1 nm. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 19 shows the result of examining the voltage-luminance characteristic, and FIG. 20 shows the result of examining the luminance-current efficiency characteristic. In FIG. 19, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 20, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  In addition, an emission spectrum of the light-emitting element manufactured in this embodiment is shown in FIG. In FIG. 21, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). From FIG. 21, it was found that the light-emitting element of this example had a peak of emission spectrum at 479 nm and emitted blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.16, 0.29), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, after evacuating the vacuum apparatus and reducing the pressure to 1 × 10 ⁻⁴ Pa, a first layer 303 made of copper phthalocyanine was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 20 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of BSPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 40 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing t-BuDNA and PCABPA was formed on the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of t-BuDNA to PCABPA was 1: 0.1 = t-BuDNA: PCABPA. As a result, PCABPA is in a state of being dispersed in a layer made of t-BuDNA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 20 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

  Next, a fifth layer 307 made of calcium fluoride was formed on the fourth layer 306 by an evaporation method. The thickness of the fifth layer 307 was set to 1 nm. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 22 shows the result of examining the voltage-luminance characteristic, and FIG. 23 shows the result of examining the luminance-current efficiency characteristic. In FIG. 22, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 23, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  In addition, an emission spectrum of the light-emitting element manufactured in this example is shown in FIG. In FIG. 24, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). From FIG. 24, it was found that the light-emitting element of this example had a peak of emission spectrum at 474 nm and emitted blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.16, 0.25), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, the inside of the vacuum apparatus was evacuated and the pressure was reduced to 1 × 10 ⁻⁴ Pa, and then a first layer 303 made of DNTPD was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 50 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 10 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing CzPA and PCABPA was formed over the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of CzPA and PCABPA was 1: 0.05 = CzPA: PCABPA. As a result, PCABPA is dispersed in a layer made of CzPA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 20 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

  Next, a fifth layer 307 made of calcium fluoride was formed on the fourth layer 306 by an evaporation method. The thickness of the fifth layer 307 was set to 1 nm. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 25 shows the results of examining the voltage-luminance characteristics, and FIG. 26 shows the results of examining the luminance-current efficiency characteristics. In FIG. 25, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 26, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  FIG. 27 shows an emission spectrum of the light-emitting element manufactured in this example. In FIG. 27, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). From FIG. 27, it was found that the light-emitting element of this example had a peak of emission spectrum at 478 nm and exhibited blue light emission. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.16, 0.28), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, the inside of the vacuum apparatus was evacuated and the pressure was reduced to 1 × 10 ⁻⁴ Pa, and then a first layer 303 made of DNTPD was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 50 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 10 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing CzPA and PCABPA was formed over the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of CzPA to PCABPA was 1: 0.04 = CzPA: PCABPA. As a result, PCABPA is dispersed in a layer made of CzPA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 10 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

Next, a fifth layer 307 containing Alq ₃ and Li was formed over the fourth layer 306 by a co-evaporation method. The thickness of the fifth layer 307 was set to 10 nm. The mass ratio between Alq ₃ and Li was 1: 0.01 = Alq ₃ : Li. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 28 shows the results of examining the voltage-luminance characteristics, and FIG. 29 shows the results of examining the luminance-current efficiency characteristics. In FIG. 28, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 29, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  FIG. 30 shows an emission spectrum of the light-emitting element manufactured in this example. In FIG. 30, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). FIG. 30 indicates that the light-emitting element of this example has a light emission peak at 487 nm and emits blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.17, 0.32), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, the inside of the vacuum apparatus was evacuated and the pressure was reduced to 1 × 10 ⁻⁴ Pa, and then a first layer 303 made of DNTPD was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 50 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 10 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing DPCzPA and PCABPA was formed over the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of DPCzPA and PCABPA was 1: 0.04 = DPCzPA: PCABPA. As a result, PCABPA is dispersed in a layer made of DPCzPA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 10 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

Next, a fifth layer 307 containing Alq ₃ and Li was formed over the fourth layer 306 by a co-evaporation method. The thickness of the fifth layer 307 was set to 10 nm. The mass ratio between Alq ₃ and Li was 1: 0.01 = Alq ₃ : Li. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 31 shows the results of examining the voltage-luminance characteristics, and FIG. 32 shows the results of examining the luminance-current efficiency characteristics. In FIG. 31, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 32, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  In addition, an emission spectrum of the light-emitting element manufactured in this example is shown in FIG. In FIG. 33, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). FIG. 33 indicates that the light-emitting element of this example has a light emission peak at 487 nm and emits blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.17, 0.32), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, the inside of the vacuum apparatus was evacuated and the pressure was reduced to 1 × 10 ⁻⁴ Pa, and then a first layer 303 made of DNTPD was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 50 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 10 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing t-BuDNA and PCABPA was formed on the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of t-BuDNA to PCABPA was 1: 0.04 = t-BuDNA: PCABPA. As a result, PCABPA is in a state of being dispersed in a layer made of t-BuDNA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 10 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

Next, a fifth layer 307 containing Alq ₃ and Li was formed over the fourth layer 306 by a co-evaporation method. The thickness of the fifth layer 307 was set to 10 nm. The mass ratio between Alq ₃ and Li was 1: 0.01 = Alq ₃ : Li. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 34 shows the results of examining the voltage-luminance characteristics, and FIG. 35 shows the results of examining the luminance-current efficiency characteristics. In FIG. 34, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 35, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  FIG. 36 shows an emission spectrum of the light-emitting element manufactured in this example. In FIG. 36, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). FIG. 36 indicates that the light-emitting element of this example has a light emission spectrum peak at 482 nm and emits blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.16, 0.29), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, the inside of the vacuum apparatus was evacuated and the pressure was reduced to 1 × 10 ⁻⁴ Pa, and then the first layer 303 made of CuPc was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 20 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 40 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing CzPA and PCABPA was formed over the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of CzPA to PCABPA was 1: 0.04 = CzPA: PCABPA. As a result, PCABPA is dispersed in a layer made of CzPA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 10 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

Next, a fifth layer 307 containing Alq ₃ and Li was formed over the fourth layer 306 by a co-evaporation method. The thickness of the fifth layer 307 was set to 10 nm. The mass ratio between Alq ₃ and Li was 1: 0.01 = Alq ₃ : Li. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 37 shows the results of examining the voltage-luminance characteristics, and FIG. 38 shows the results of examining the luminance-current efficiency characteristics. In FIG. 37, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 38, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  FIG. 39 shows an emission spectrum of the light-emitting element manufactured in this example. In FIG. 39, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). FIG. 39 indicates that the light-emitting element of this example has a light emission peak at 481 nm and emits blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.17, 0.31), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, the inside of the vacuum apparatus was evacuated and the pressure was reduced to 1 × 10 ⁻⁴ Pa, and then the first layer 303 made of CuPc was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 20 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 40 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing DPCzPA and PCABPA was formed over the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of DPCzPA and PCABPA was 1: 0.04 = DPCzPA: PCABPA. As a result, PCABPA is dispersed in a layer made of DPCzPA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 10 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

Next, a fifth layer 307 containing Alq ₃ and Li was formed over the fourth layer 306 by a co-evaporation method. The thickness of the fifth layer 307 was set to 10 nm. The mass ratio between Alq ₃ and Li was 1: 0.01 = Alq ₃ : Li. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. FIG. 40 shows the results of examining the voltage-luminance characteristics, and FIG. 41 shows the results of examining the luminance-current efficiency characteristics. In FIG. 40, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 41, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  In addition, an emission spectrum of the light-emitting element manufactured in this example is shown in FIG. In FIG. 42, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). FIG. 42 indicates that the light-emitting element of this example has a light emission peak at 485 nm and emits blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.17, 0.31), and it was found that the light-emitting element of this example exhibits blue with good color purity.

  In this example, a method for manufacturing a light-emitting element using PCABPA synthesized by the method described in Synthesis Example 1 as a light-emitting substance and operation characteristics of the light-emitting element will be described. Note that the light-emitting element of this example has a structure in which five layers having different layers and different thicknesses are stacked between the first electrode and the second electrode. Since this is the same as the light-emitting element of Example 2, this example will also be described with reference to FIG. 15 used in the description of Example 2.

  As shown in FIG. 15, indium tin oxide containing silicon oxide was formed over a glass substrate 301 by a sputtering method, so that a first electrode 302 was formed. The thickness of the first electrode 302 was set to 110 nm. The electrodes were formed to have a square shape with a size of 2 mm × 2 mm.

  Next, the glass substrate 301 over which the first electrode 302 was formed was fixed to a holder provided in a vacuum evaporation apparatus.

Next, the inside of the vacuum apparatus was evacuated and the pressure was reduced to 1 × 10 ⁻⁴ Pa, and then the first layer 303 made of CuPc was formed on the first electrode 302 by vapor deposition. The thickness of the first layer 303 was set to 20 nm. The first layer 303 is a layer that functions as a hole injection layer when the light emitting element is operated.

  Next, a second layer 304 made of NPB was formed on the first layer 303 by an evaporation method. The thickness of the second layer 304 was set to 40 nm. The second layer 304 is a layer that functions as a hole transport layer when the light emitting element is operated.

  Next, a third layer 305 containing t-BuDNA and PCABPA was formed on the second layer 304 by a co-evaporation method. The thickness of the third layer 305 was 40 nm, and the mass ratio of t-BuDNA to PCABPA was 1: 0.04 = t-BuDNA: PCABPA. As a result, PCABPA is in a state of being dispersed in a layer made of t-BuDNA. The third layer 305 functions as a light emitting layer when the light emitting element is operated. PCABPA functions as a light-emitting substance.

Next, a fourth layer 306 made of Alq ₃ was formed on the third layer 305 by an evaporation method. The thickness of the fourth layer 306 was set to 10 nm. The fourth layer 306 functions as an electron transport layer when the light emitting element is operated.

Next, a fifth layer 307 containing Alq ₃ and Li was formed over the fourth layer 306 by a co-evaporation method. The thickness of the fifth layer 307 was set to 10 nm. The mass ratio between Alq ₃ and Li was 1: 0.01 = Alq ₃ : Li. The fifth layer 307 functions as an electron injection layer when the light emitting element is operated.

  Next, a second electrode 308 made of aluminum was formed over the fifth layer 307. The thickness of the second electrode 308 was set to 200 nm.

  In the light-emitting element manufactured as described above, a current flows when a voltage is applied so that the potential of the first electrode 302 is higher than the potential of the second electrode 308, and the third element functions as a light-emitting layer. In the layer 305, electrons and holes are recombined to generate excitation energy, and light is emitted when the excited PCABPA returns to the ground state.

  The light-emitting element was sealed in a glove box under a nitrogen atmosphere so that the light-emitting element was not exposed to the air, and then the operating characteristics of the light-emitting element were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The measurement results are shown in FIGS. 43 shows the results of examining the voltage-luminance characteristics, and FIG. 44 shows the results of examining the luminance-current efficiency characteristics. In FIG. 43, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In FIG. 44, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A).

  FIG. 45 shows an emission spectrum of the light-emitting element manufactured in this example. In FIG. 45, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity (arbitrary unit). From FIG. 45, it is found that the light-emitting element of this example has a light emission peak at 476 nm and emits blue light. Further, the chromaticity coordinates in the CIE color system are (x, y) = (0.16, 0.28), and it was found that the light-emitting element of this example exhibits blue with good color purity.

4A and 4B illustrate a light-emitting element of the present invention. 4A and 4B illustrate a light-emitting element of the present invention. 4A and 4B illustrate a light-emitting device to which the present invention is applied. FIG. 6 illustrates a circuit included in a light-emitting device to which the present invention is applied. The top view of the light-emitting device to which this invention is applied. 4A and 4B illustrate a frame operation of a light-emitting device to which the present invention is applied. FIG. 6 illustrates a circuit included in a light-emitting device to which the present invention is applied. Sectional drawing of the light-emitting device to which this invention is applied. The figure of the electronic device to which this invention is applied. The figure which shows the absorption spectrum of the anthracene derivative of this invention. The figure which shows the emission spectrum of the anthracene derivative of this invention. The figure which shows the measurement result by cyclic voltammetry (CV) about the anthracene derivative of this invention. ¹ H-NMR chart of PCA synthesized in Synthesis Example 1. 1 is a ¹ H-NMR chart of PCABPA synthesized in Synthesis Example 1. FIG. 3A and 3B illustrate a light-emitting element manufactured in an example. 4 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 2. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 2. 4 shows an emission spectrum of the light-emitting element manufactured in Example 2. 4 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 3. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 3. 4 shows an emission spectrum of the light-emitting element manufactured in Example 3. 4 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 4. FIG. 4 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 4. 4 shows an emission spectrum of the light-emitting element manufactured in Example 4. 10 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 5. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 5. 6 shows an emission spectrum of the light-emitting element manufactured in Example 5. 10 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 6. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 6. 8 shows an emission spectrum of the light-emitting element manufactured in Example 6. 10 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 7. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 7. 8 shows an emission spectrum of the light-emitting element manufactured in Example 7. 8 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 8. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 8. 8 shows an emission spectrum of the light-emitting element manufactured in Example 8. 10 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 9. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 9. 10 shows an emission spectrum of the light-emitting element manufactured in Example 9. 10 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 10. FIG. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 10. 10 shows an emission spectrum of the light-emitting element manufactured in Example 10. 10 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 11. 10 shows luminance-current efficiency characteristics of the light-emitting element manufactured in Example 11. 10 shows an emission spectrum of the light-emitting element manufactured in Example 11. 4A and 4B illustrate an embodiment of a light-emitting device of the present invention. ¹ H-NMR chart of PCABBA synthesized in Synthesis Example 2. The figure which shows the absorption spectrum of the anthracene derivative of this invention. The figure which shows the emission spectrum of the anthracene derivative of this invention.

Explanation of symbols

101 first electrode 102 second electrode 111 hole injection layer 112 hole transport layer 113 light emitting layer 114 electron transport layer 115 electron injection layer 201 first electrode 202 second electrode 211 hole injection layer 212 hole transport Layer 213 light emitting layer 214 electron transport layer 215 electron injection layer 301 glass substrate 302 first electrode 303 first layer 304 second layer 305 third layer 306 fourth layer 307 fifth layer 308 second electrode 6500 Substrate 6503 FPC
6504 Printed Wiring Board (PWB)
6511 Pixel portion 6512 Source signal line driving circuit 6513 Writing gate signal line driving circuit 6514 Erasing gate signal line driving circuit 901 First transistor 902 Second transistor 903 Light emitting element 911 Gate signal line 912 Source signal line 913 Writing Gate signal line driving circuit 914 erasing gate signal line driving circuit 915 source signal line driving circuit 916 power supply 917 current supply line 918 switch 919 switch 920 switch 1001 first transistor 1002 second transistor 1003 gate signal line 1004 source signal line 1005 Current supply line 1006 Electrode 501 Subframe 502 Subframe 503 Subframe 504 Subframe 501a Writing period 501b Holding period 502a Writing period 502b Holding period 503a Writing Only period 503b holding period 504a writing period 504b holding period 504c erasing period 504d non-light emitting period 2101 first transistor 2102 holding capacitor 2103 second transistor 2111 erasing diode 2104 light emitting element 2105 signal line 2106 power line 2108 second power line 2107 first 1 gate line 2117 second gate line 10 substrate 11 transistor 12 light emitting element 13 first electrode 14 second electrode 15 light emitting layers 16a, 16b, 16c first interlayer insulating film 17 wiring 18 partition walls 19a, 19b second interlayer insulating Membrane 5521 Main body 5522 Housing 5523 Display unit 5524 Keyboard 5551 Display unit 5552 Main body 5553 Antenna 5554 Audio output unit 5555 Audio input unit 5556 Operation switch 5531 Display unit 5532 Housing 5533 Speaker 1 01 substrate 1902 electrode 1904 partition layer 1905 emitting layer 1906 electrodes 1907 substrate

Claims (8)

An anthracene derivative represented by the structural formula (1).
An anthracene derivative represented by Structural Formula (13)
An anthracene derivative represented by the general formula (6).
(In the formula, X ² represents an arylene group having 6 to 15 carbon atoms.)
A light-emitting element having a layer containing the anthracene derivative according to any one of claims 1 to 3 between electrodes. Light-emitting device using a light emitting element including an anthracene derivative described as a light-emitting substance in any one of claims 1 to 3. A light-emitting device using a light-emitting element including the anthracene derivative according to any one of claims 1 to 3 as a host. A light emitting device having a pixel portion the light-emitting element described in any one of claims 4 to 6. The electronic device which used the light-emitting device of Claim 7 for the display part.