KR102081119B1 - Organic light emitting device and organic light emitting display device using the same - Google Patents

Abstract

The present invention relates to an organic light emitting device capable of reducing driving voltage and increasing efficiency, and an organic light emitting display device using the same. The organic light emitting device according to the present invention includes: a first electrode and a second electrode facing each other on a substrate; A plurality of stacks including a light emitting layer stacked between the first and second electrodes to emit specific light, and an N type charge generation layer and a P type formed between the stacks to adjust the charge balance between the stacks. A charge generation layer comprising a charge generation layer, wherein the P type charge generation layer comprises a first organic material having at least one electron-withdrawing substituent and at least one aromatic amine; 2 is formed of an organic material, the N-type charge generating layer is an alkali metal to an organic material containing a heterocyclic ring containing N Or an alkaline earth metal is doped.

Description

Organic light emitting device and organic light emitting display device using the same {ORGANIC LIGHT EMITTING DEVICE AND ORGANIC LIGHT EMITTING DISPLAY DEVICE USING THE SAME}

The present invention relates to an organic light emitting diode and an organic light emitting display using the same, and more particularly, to an organic light emitting diode capable of reducing driving voltage and increasing efficiency and an organic light emitting display using the same.

Video display devices that implement a variety of information on the screen are the core technologies of the information and communication era, and are developing in a direction that is thinner, lighter, more portable, and high-performance. Accordingly, an organic light emitting diode display using an organic light emitting diode that displays an image by controlling the amount of light emitted from the organic light emitting layer as a flat panel display capable of reducing weight and volume, which is a disadvantage of a cathode ray tube (CRT), has been in the spotlight. Such an organic light emitting diode display does not require a separate light source and is considered to be a competitive application for compactness and vivid color display of the device.

At this time, the organic light emitting device (OLED) is a self-luminous device using a thin light emitting layer between the electrodes has the advantage that can be thinned like a paper. In detail, the organic light emitting diode includes an anode, a hole transport layer (HTL), a hole injection layer (HIL), an emission layer, an electron injection layer (EIL), and an electron injection layer (Electron). Transport Layer (ETL), cathode (cathode).

As described above, the organic light emitting diode used in the organic light emitting diode display may be formed as a single stack, but has a multi-stack structure having a plurality of stacks.

Such an organic light emitting device having a multi-stack structure includes a first stack, a charge generating layer, and a second stack sequentially stacked between an anode and a cathode, an anode and a cathode.

In this case, the first stack includes a hole transport layer, a light emitting layer, and an electron transport layer formed on the anode, and the second stack includes a hole transport layer, a light emitting layer, and an electron transport layer.

The charge generation layer is positioned between the first and second stacks to adjust the charge balance of the first and second stacks, and includes an N type charge generation layer and a P type charge generation layer.

In this case, the P-type charge generating layer generates holes and electrons, injects electrons into the N-type charge generating layer, and injects holes into the hole transport layer of the second stack. However, electrons and holes are generated at the interface between the P-type charge generating layer and the hole transport layer of the second stack. Accordingly, electrons generated from the P type charge generation layer do not properly move to the N type charge generation layer. That is, a problem arises in that the injection characteristics of the N-type charge generation layer are lowered, thereby increasing the driving voltage.

The present invention has been made to solve the above problems, and provides an organic light emitting device capable of reducing driving voltage and increasing efficiency and an organic light emitting display device using the same.

In order to achieve the above technical problem, the organic light emitting device according to the present invention comprises: a first electrode and a second electrode facing each other on a substrate; A plurality of stacks stacked between the first and second electrodes and including a light emitting layer to emit specific light; A charge generation layer formed between the stacks, the charge generation layer comprising an N-type charge generation layer and a P-type charge generation layer to adjust the charge balance between the stacks, wherein the P-type charge generation layer includes at least one electron draw. a first organic material having a substituent and a second organic material including at least one aromatic amine, wherein the N type charge generation layer comprises a heterocyclic ring including N; The organic material containing is characterized in that the alkali metal or alkaline earth metal is doped.

In order to achieve the above technical problem, an organic light emitting diode display according to the present invention includes a driving thin film transistor formed on a substrate; A first electrode connected to the driving thin film transistor; A plurality of stacks stacked on the first electrode and including a light emitting layer to emit specific light; A charge generation layer formed between the stacks, the charge generation layer comprising an N type charge generation layer and a P type charge generation layer to adjust the charge balance between the stacks, and a second electrode formed on the stacks; The charge generating layer is formed of a first organic material having at least one electron-withdrawing substituent and a second organic material including at least one aromatic amine, and the N type charge generating layer is formed of N. An alkali metal or an alkaline earth metal is doped into an organic material including a heterocyclic ring.

The first organic material is formed of a heterocyclic ring compound including at least one electron drag substituent of CN, NO ₂ , F, Cl, Br, and I.

The first organic material is characterized in that represented by the following [Formula 1].

[Formula 1]

.

.

The second organic material may be selected from any one of the following [Formula 2-1], [Formula 2-2], and [Formula 2-3].

[Formula 2-1] [Formula 2-2]

[Formula 2-3]

.

.

[Formula 2-1], [Formula 2-2], [Formula 2-3] R1, R2, R3, R4, R5, R6, R7, R8 are selected from C ₆ ~ C ₂₀ aromatic group, R9 , R10 is hydrogen, or C ₆ ~ C ₂₀ Selected from an aromatic group, or have at least one N, S, P element, C ₃ ~ C ₁₇ It is characterized by being selected from heterocyclic compounds.

The second organic material, which is mixed with the first organic material to form the P-type charge generating layer, has a volume ratio of 1 to 50%.

The second organic material, which is mixed with the first organic material to form the P-type charge generating layer, has a volume ratio of 15 to 35%.

The amine (Amine) has at least one nitrogen of less than 6, Aromatic (Aromatic) is characterized in that having an aromatic ring (Aromatic Ring) of 6 to 40 carbon atoms.

The aromatic ring is a phenyl (Phenyl), phenyl (Phenyl) derivatives, naphthyl (Naphthyl), naphthyl (Naphthyl) derivatives, anthracene (Anthrancene), anthracene derivatives (Pyrene), pi It is characterized in that it is selected from at least one of styrene (Pyrene) derivatives, perylene (Perylene), perylene (Perylene) derivatives.

The N-type charge generating layer is characterized in that the carbon number containing 20 or more than 60 carbon atoms containing a heterocyclic ring (N) containing.

The alkali metal is selected from Li, Na, K, Rb, Cs, Fr, and Yb, and the alkaline earth metal is selected from Be, Mg, Ca, Sr, Ba, and Ra.

The alkaline earth metal or the alkali metal is doped with 0.5% to 10% based on the volume of the N-type charge generating layer.

The N-type charge generating layer is formed of a compound having a core of pyrene (Pyrene) including a heterocyclic ring containing N, and the following [Formula 3-1] to [Formula 3-5] At least one of the pyrene (Pyrene) compound is characterized in that it is selected.

[Formula 3-1] [Formula 3-2]

[Formula 3-3] [Formula 3-4] [Formula 3-5]

.

.

R1, R2, R3, and R4 of [Formula 3-1] to [Formula 3-5] are each independently selected from [Formula 4-1] to [Formula 4-72], and the R1, R2 and R3 , R4 is characterized by different or the same.

[Formula 4-1] [Formula 4-2] [Formula 4-3]

[Formula 4-4] [Formula 4-5] [Formula 4-6]

.

.

[Formula 4-7] [Formula 4-8] [Formula 4-9]

[Formula 4-10] [Formula 4-11] [Formula 4-12]

[Formula 4-13] [Formula 4-14]

[Formula 4-15] [Formula 4-16]

[Formula 4-17] [Formula 4-18]

[Formula 4-19] [Formula 4-20] [Formula 4-21]

    [Formula 4-22] [Formula 4-23] [Formula 4-23]

   [Formula 4-25] [Formula 4-26]

[Formula 4-27] [Formula 4-28]

[Formula 4-29] [Formula 4-30] [Formula 4-31]

[Formula 4-32] [Formula 4-33]

[Formula 4-34] [Formula 4-35] [Formula 4-36]

[Formula 4-37] [Formula 4-38]

[Formula 4-39] [Formula 4-40]

[Formula 4-41] [Formula 4-42] [Formula 4-43]

[Formula 4-44] [Formula 4-45]

[Formula 4-46] [Formula 4-47] [Formula 4-48]

[Formula 4-49] [Formula 4-50]

[Formula 4-51] [Formula 4-52]

[Formula 4-53] [Formula 4-54] [Formula 4-55]

[Formula 4-56] [Formula 4-57]

[Formula 4-58] [Formula 4-59] [Formula 4-60]

[Formula 4-61] [Formula 4-62]

[Formula 4-63] [Formula 4-64]

 [Formula 4-65] [Formula 4-66]

[Formula 4-67] [Formula 4-68]

   [Formula 4-69] [Formula 4-70]

[Formula 4-71] [Formula 4-72]

In the organic light emitting device according to the present invention, electrons and holes are evenly distributed in the P type charge generating layer by forming the P type charge generating layer with the first and second organic materials according to the present invention. In addition, a gap state is formed in the N-type charge generation layer by doping the N-type charge generation layer with an alkali metal or alkaline earth metal, and electrons are easily injected from the P-type charge generation layer into the N-type charge generation layer by the gap state. Done.

Accordingly, the P-type charge generation layer can inject and transfer electrons well into the N-type charge generation layer, thereby lowering the driving voltage of the organic light emitting device.

1 is a view showing an organic light emitting device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an embodiment according to the organic light emitting diode illustrated in FIG. 1.
3 is a diagram illustrating a band diagram according to the organic light emitting diode of FIG. 2.
Figure 4a is a graph showing the driving voltage of the organic electroluminescent device according to the present invention and the driving voltage of the organic electroluminescent device according to a comparative example, Figure 4b is an organic according to the efficiency and comparative example of the organic electroluminescent device according to the present invention It is a graph which shows the efficiency of a light emitting element.
5A and 5B are graphs for describing driving voltages and lifetimes of organic light emitting diodes according to volume ratios of the second organic materials included in the P-type charge generation layer of the organic light emitting diode according to the present invention.
6 is a cross-sectional view illustrating an organic light emitting diode display using an organic light emitting diode according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The construction of the present invention and the effects thereof will be clearly understood through the following detailed description. Prior to the detailed description of the present invention, the same components are denoted by the same reference numerals as much as possible even if shown on different drawings, and the known components will be omitted if it is determined that the gist of the present invention may obscure the gist of the present invention. do.

Preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 6.

1 is a view showing an organic light emitting device according to an embodiment of the present invention, FIG. 2 is a view showing an embodiment according to the organic light emitting device shown in FIG. 1, FIG. The band diagram according to the figure.

As shown in FIG. 1, an organic light emitting diode according to an exemplary embodiment of the present invention is disposed between a first electrode 412 and a second electrode 414 facing each other on a substrate, and between the first and second electrodes 412 and 414. A multi stack comprising a plurality of stacks 420, 424, 426 stacked to include a light emitting layer and stacked between the stacks 420, 424, 426 and a charge generating layer 422 for controlling the charge balance of the stacks 420, 424, 426. -Has a stack structure. The plurality of stacks 420, 424, 426 included in the organic light emitting diode having a multi-stack structure may include light emitting layers having the same color as each other, or may include light emitting layers having different colors. In the organic light emitting device having a multi-stack structure including light emitting layers having different colors in each stack, light emitted from the light emitting layers of each stack may be mixed to implement white light.

In this case, the organic light-emitting device of the multi-stack structure of the present invention includes the first stack 210, the charge generation layer 220, and the second stack 230 in conjunction with FIG. 2, and each stack has a different color. An example of including the light emitting layer will be described.

Referring to FIG. 2, an organic light emitting device having a multi-stack structure according to the present invention may include a first electrode 242 and a second electrode 244, a first electrode 242, and a first electrode 242 opposing each other on a substrate 100. It has a multi-stack structure including a first stack 210, a charge generation layer 220, and a second stack 230 stacked between two electrodes 244. The organic light emitting device having a multi-stack structure includes light emitting layers having different colors in each stack, and light emitted from the light emitting layers of each stack is mixed to realize white light. In the organic light emitting diode according to the exemplary embodiment of the present invention, blue light emitted from the first light emitting layer 218 and yellow-green light emitted from the second light emitting layer 234 are mixed with white light. Is implemented. In this case, since the light emitted from each stack is mixed to implement white light, each of the first and second light emitting layers 218 and 234 is not limited to blue light and yellow-green light. In addition, although FIG. 2 illustrates a bottom emission method in which light emitted from the first and second emission layers 218 and 234 is emitted downward, the organic light emitting device according to an embodiment of the present invention may be a top emission method or a double emission method. Can emit light. Therefore, it is not limited to this.

The first electrode 242 is a transparent conductive material such as transparent conductive oxide (TCO) as an anode, and is formed of indium tin oxide (ITO) or indium zinc oxide (IZO). .

The second electrode 244 is formed of gold (Au), molybdenum (MO), chromium (Cr), copper (Cu), LiF, or the like as a reflective metal such as aluminum, or an aluminum and a LiF alloy.

The first stack 210 includes a hole injection layer (HIL) 214 and a first hole transport layer (HTL1; 216) between the first electrode 242 and the charge generation layer 220. The first emitting layer (EML1) 218 and the first electron transport layer (ETL1) 212 are sequentially stacked. In this case, the first emission layer 218 emits blue light to the emission layer including the fluorescent blue dopant and the host. In addition, at least one hole transport layer may be further provided between the first hole transport layer 216 and the first light emitting layer 218.

The second stack 230 includes a second hole transport layer HTL2 232, a second emission layer EML2 234, and a second electron transport layer ETL2 236 between the second electrode 244 and the charge generation layer 220. Electron Injection Layer (EIL) 238 is sequentially stacked. In this case, the second light emitting layer 234 emits a yellow-green color as a light emitting layer including a phosphorescent yellow-green dopant and a host. In addition, at least one hole transport layer may be further provided between the second hole transport layer 236 and the second light emitting layer 234.

A charge generation layer (CGL) 220 is formed between the stacks to adjust the charge balance between the stacks. The charge generation layer 220 is positioned adjacent to the second stack 230 to form a P-type charge generation layer (P-CGL) 220b for generating and injecting electrons and holes, and to transfer electrons to the first stack 210. N-type charge generation layer (N-CGL) 220a injected into the first electron transport layer 212.

The P type charge generation layer 220b generates holes and electrons, injects the generated holes into the second hole transport layer 232 of the adjacent second stack 230, and injects the generated electrons into the N type charge generation layer 220a. ) The P type charge generation layer 220b is formed of a first organic material and a second organic material. The first organic material is a heterocyclic ring compound having at least one electron-withdrawing substituent, and the electron withdrawing substituent is formed of at least one of CN, NO ₂ , F, Cl, Br, and I. The second organic material includes at least one aromatic amine, and the amine (Amine) has one or more and six or less nitrogens, and the aromatics (Aromatic) has an aromatic ring having six or more carbon atoms and no more than 40 carbon atoms. Aromatic Ring)

Here, the aromatic ring (Aromatic Ring) is a phenyl (Phenyl), phenyl (Phenyl) derivatives, naphthyl (Naphthyl), naphthyl (Naphthyl) derivatives, anthracene (Anthrancene), anthracene derivatives (Pyrene), It is selected from at least one of a pyrene derivative, a perylene (Perylene), a perylene (Perylene) derivative. In addition, the second organic material mixed with the first organic material to form the P-type charge generating layer 220b has a volume ratio of 1 to 50%, and preferably 15 to 35%.

As described above, electrons and holes are evenly distributed in the P-type charge generation layer 220b by forming the first and second organic materials on the P-type charge generation layer 220b.

In addition, the first organic material is formed by the following [Formula 1].

[Formula 1]

The second organic material is selected from any one of the following [Formula 2-1], [Formula 2-2], and [Formula 2-3].

  [Formula 2-1] [Formula 2-2] [Formula 2-3]

.

.

[Formula 2-1], [Formula 2-2], [Formula 2-3] R1, R2, R3, R4, R5, R6, R7, R8 are selected from C ₆ ~ C ₂₀ aromatic group, R9 , R10 is hydrogen, or C ₆ ~ C ₂₀ Selected from an aromatic group or have at least one of N, S, and P elements, and have C ₃ to C ₁₇ Heterocyclic compounds.

Specific examples of the compounds of [Formula 2-1], [Formula 2-2], and [Formula 2-3] are as follows.

        PC-01 PC-02

           PC-03 PC-04

         PC-05 PC-06

           PC-07 PC-08

            PC-09 PC-10

PC-11 PC-12

            PC-13 PC-14

            PC-15 PC-16

            PC-17 PC-18

            PC-19 PC-20

            PC-21 PC-22

            PC-23 PC-24

            PC-25 PC-26

            PC-27 PC-28

            PC-29 PC-30

            PC-31 PC-32

PC-33 PC-34

            PC-35 PC-36

The N type charge generation layer 220a injects and transports electrons injected from the P type charge generation layer 220b to the first electron transport layer 212 of the first stack 210. The N type charge generation layer 220a is doped with an alkali metal or an alkaline earth metal to an organic material including a heterocyclic ring including N. The N type charge generation layer 220a has 20 to 60 carbon atoms including a heterocyclic ring including N. Alkali metals are selected from Li, Na, K, Rb, Cs, Fr and Yb, and alkaline earth metals are selected from Be, Mg, Ca, Sr, Ba, and Ra. The alkaline earth metal or the alkali metal is doped at 0.5% to 10% based on the volume of the N type charge generation layer 220a. The N type charge generation layer 220a is formed of a compound having a core of pyrene including a heterocyclic ring including N, and is represented by [Formula 3-1] to [Formula 3-5] ] At least one pyrene compound.

On the other hand, sp ² -Nitrogen (double-bonded nitrogen) of the material of the N-type charge generation layer 220a is relatively rich in electrons and is virtually bound with an alkali metal to form a gap state. As shown in FIG. 3, electrons generated from the P-type charge generation layer 220b are easily injected into the N-type charge generation layer 220a by a gap state. That is, holes in the LUMO level of the P type charge generation layer 220b are easily transferred to the LUMO level of the N type charge generation layer through the gap state made by the doping of the alkali metal. In addition, as shown in FIG. 3, the holes generated from the P-type charge generation layer 220b may be easily transferred to the HOMO level of the second hole transport layer 232.

[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

[Formula 3-4]

[Formula 3-5]

R1, R2, R3, and R4 of each of [Formula 3-1] to [Formula 3-5] are independently selected from [Formula 4-1] to [Formula 4-72]. R1, R2, R3, and R4 may be formed of different compounds or may be formed of the same compound. For example, R1, R2, R3, and R4 of [Formula 3-1] are formed of the same [Formula 4-1], or R1 of [Formula 3-1] is [Formula 4-1], and R2 is [Formula 3] 4-2], R3 is [Formula 4-3], R4 is formed by [Formula 4-4] or [Formula 4-3].

[Formula 4-1] [Formula 4-2] [Formula 4-3]

[Formula 4-4] [Formula 4-5] [Formula 4-6]

.

.

[Formula 4-7] [Formula 4-8] [Formula 4-9]

[Formula 4-10] [Formula 4-11] [Formula 4-12]

[Formula 4-13] [Formula 4-14]

[Formula 4-15] [Formula 4-16]

[Formula 4-17] [Formula 4-18]

[Formula 4-19] [Formula 4-20]

[Formula 4-21] [Formula 4-22]

[Formula 4-23] [Formula 4-24]

[Formula 4-25] [Formula 4-26]

[Formula 4-27] [Formula 4-28]

[Formula 4-29] [Formula 4-30] [Formula 4-31]

[Formula 4-32] [Formula 4-33]

[Formula 4-34] [Formula 4-35] [Formula 4-36]

[Formula 4-37] [Formula 4-38]

[Formula 4-39] [Formula 4-40]

[Formula 4-41] [Formula 4-42] [Formula 4-43]

[Formula 4-44] [Formula 4-45]

[Formula 4-46] [Formula 4-47] [Formula 4-48]

[Formula 4-49] [Formula 4-50]

[Formula 4-51] [Formula 4-52]

[Formula 4-53] [Formula 4-54] [Formula 4-55]

[Formula 4-56] [Formula 4-57]

[Formula 4-58] [Formula 4-59] [Formula 4-60]

[Formula 4-61] [Formula 4-62]

[Formula 4-63] [Formula 4-64]

 [Formula 4-65] [Formula 4-66]

[Formula 4-67] [Formula 4-68]

 [Formula 4-69] [Formula 4-70]

[Formula 4-71] [Formula 4-72]

Figure 4a is a graph showing the driving voltage of the organic electroluminescent device according to the present invention and the driving voltage of the organic electroluminescent device according to the comparative example, Figure 4b is the organic electroluminescent device according to the present invention and the organic according to the comparative example It is a graph which shows the efficiency of a light emitting element. The driving voltage and efficiency of the organic EL device according to the present invention will be described with reference to FIGS. 4A, 4B, and [Table 1].

N-CGL
P-CGL Current density
(10mA / ㎠) Current density
(50mA / ㎠) First organic matter Second organic matter Secondary organics
volume(%) Driving
Voltage (V) efficiency
(cd / A) Driving
Voltage (V) Example 1 [Formula 3-5]
+ [Formula 4-1] HAT-CN PC-01 30 7.7 76 9.8 Comparative Example 1 NCREF
HAT-CN - -
8.7 75 10.0 Comparative Example 2 [Formula 3-5]
+ [Formula 4-1] HAT-CN PCREF 30
12.2 65 5.1

The organic light emitting device according to Comparative Example 1 and Comparative Example 2 and Example 1 of the present invention described in Table 1 may include a first electrode / HIL / HTL1 / EML1 / ETL1 / N-CGL / P-CGL / HTL2 / EML / It consists of an ETL2 / EIL / second electrode. The N-type charge generating layers of Example 1 and Comparative Example 2 are formed of a pyrene compound of [Chemical Formula 3-5], and R1 of [Chemical Formula 3-5] is formed of a compound of [Chemical Formula 4-1] The N-type charge generation layer NCREF of Comparative Example 1 is formed of BCP (bathcuproine), and the first organic material of the P-type charge generation layers of Example 1 and Comparative Examples 1 and 2 is HAT- of [Formula 1]. The second organic material of the P-type charge generating layer of Example 1 is formed of PC-01, and the P-type charge generating layer (PCREF) of Comparative Example 2 is formed of 9,10-bisphenylamino anthracene. Will be explained.

As shown in Table 1 and FIG. 4A, the organic light emitting diode display according to the present invention has a higher current density according to voltage than the Comparative Examples 1 and 2, and provides a current density of 10 mA / cm ^{2 and} a current density of 50 mA / cm ² . It can be seen that the driving voltage to be lowered than Comparative Examples 1 and 2. In addition, as shown in Table 1 and FIG. 4B, the organic light emitting diode display according to the present invention is more efficient than the Comparative Examples 1 and 2, and the roll-off phenomenon is improved to improve the light emission efficiency at a high current. Can be improved.

5A and 5B are graphs for describing a driving voltage and a lifespan of an organic light emitting diode according to a volume ratio of the second organic material included in the P-type charge generating layer of the organic light emitting diode according to the present invention. 5A, 5B and [Table 2] will be described with reference to the driving voltage and lifespan of the organic EL device according to the present invention.

N-CGL
P-CGL Current density
(10mA / ㎠) Current density
(50mA / ㎠)

T95
life span First organic matter Second organic matter Secondary organics
volume(%) Driving
Voltage (V) efficiency
(cd / A) Driving
Voltage (V) Comparative example
3 [Formula 3-5]
+ [Formula 4-1] HAT-CN 7.3 81 8.42 100% Example
2 [Formula 3-5]
+ [Formula 4-1] HAT-CN PC-01 6 7.0 80 8.38 100% Example
3 [Formula 3-5]
+ [Formula 4-1] HAT-CN PC-01 15
7.1 81 8.32 110% Example
4 [Formula 3-5]
+ [Formula 4-1] HAT-CN PC-01 30
7.2 82 8.28 150%

In the organic light emitting device according to Comparative Example 3 and Examples 2 to 4 of the present invention, the first electrode / HIL / HTL1 / EML1 / ETL1 / N-CGL / P-CGL / HTL2 / EML / ETL2 / It consists of an EIL / second electrode. The N-type charge generating layers of Examples 2 to 4 and Comparative Example 3 are formed of a pyrene compound of [Chemical Formula 3-5], and R1 of [Chemical Formula 3-5] is a compound of [Chemical Formula 4-1] The first organic material of the P-type charge generating layer of Examples 2 to 4 and Comparative Example 3 is formed of HAT-CN of [Formula 1], and the second of the P-type charge generating layer of Examples 2 to 4 The organic material will be described taking the case formed of PC-01 as an example.

As shown in Table 2 and FIG. 5A, the organic light emitting diode display according to Examples 2 to 4 having the P-type charge generation layer in which the second organic material is mixed than the Comparative Example 3 has a higher current density according to voltage. It can be seen that the driving voltage for producing a current density of 10 mA / cm ^{2 and} a current density of 50 mA / cm ² is lower than that of Comparative Example 3. In addition, as shown in Table 2 and Figure 5b it can be seen that the life is improved as the content of the second organic material included in the P-type charge generating layer increases.

6 is a cross-sectional view illustrating an organic light emitting display device using an organic light emitting diode according to an exemplary embodiment of the present invention.

As illustrated in FIG. 6, the organic light emitting diode display includes a light emitting device substrate 101, and a sealing substrate 150 bonded through the light emitting device substrate 101 and the adhesive film 152.

The light emitting element substrate 101 includes a driving thin film transistor and an organic light emitting element connected to the driving thin film transistor.

As shown in FIG. 6, in the driving thin film transistor, a buffer layer 116 and an active layer 114 are formed on the light emitting device substrate 101, and the gate electrode 106 is formed in the channel region 114C of the active layer 114. ) And the gate insulating film 112 are interposed therebetween. The source electrode 108 and the drain electrode 110 are formed to be insulated from each other with the gate electrode 106 and the interlayer insulating layer 118 therebetween. The source electrode 108 and the drain electrode 110 are active layers in which n + impurities are injected through the source contact hole 124S and the drain contact hole 124D that pass through the interlayer insulating layer 126 and the gate insulating layer 112, respectively. Each of the source region 114S and the drain region 114D of the 114 is connected. In addition, the active layer 114 (LDD) region (not shown) in which n- impurity is implanted between the channel region 114C and the source and drain regions 114S and 114D to reduce the off current. ) It is also equipped. In addition, a pixel passivation layer 119 formed of an organic insulating material is formed on the driving thin film transistor formed on the substrate 101. Alternatively, the pixel passivation layer on the driving thin film transistor may be formed of two layers, an inorganic passivation layer formed of an inorganic insulating material and an organic passivation layer formed of an organic insulating material.

The organic light emitting diode includes a first insulating layer 242 connected to the drain electrode 110 and the pixel contact hole 122 of the driving thin film transistor, and a bank insulating layer 136 having a bank hole exposing the first electrode 242. And a plurality of stacks stacked on the first electrode 242 and including a light emitting layer to emit specific light, a charge generation layer formed between the stacks to adjust charge balance between the stacks, and the plurality of stacks. A second electrode 244 formed on the stacks of the substrate. In this case, the organic light emitting diode has the same components and functions as the organic light emitting diode described in detail with reference to FIGS. 1 to 3, and thus will be omitted.

The passivation layer 148 is formed between the organic light emitting element and the adhesive film 152 to prevent the organic light emitting element from being damaged by moisture, oxygen, or the like or deteriorating light emission characteristics. In particular, the passivation layer 148 is formed to contact the adhesive film 152 to block the inflow of water, hydrogen, oxygen, etc. from the side and the front surface of the organic EL device. The protective film 148 is formed of an inorganic insulating film such as SiNx or SiOx.

The storage capacitor Cst is formed by overlapping the storage lower electrode 132 and the storage upper electrode 134 doped with p + or n + impurities with the gate insulating layer 112 therebetween. The storage capacitor Cst keeps the data signal charged in the first electrode 242 stable until the next data signal is charged.

The above description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed by the claims below, and all techniques within the scope equivalent thereto will be construed as being included in the scope of the present invention.

100 substrate 210 first stack
212: first electron transport layer 214: hole injection layer
216: first hole transport layer 218: first light emitting layer
220: charge generating layer
220a: N-type charge generating layer 220b: P-type charge generating layer
230: second stack 232: second hole transport layer
234: second emission layer 236: second electron transport layer
238: electron injection layer 242: first electrode
244: second electrode

Claims (28)

A first electrode and a second electrode opposing each other on the substrate;
A plurality of stacks stacked between the first and second electrodes and including a light emitting layer to emit specific light;
A charge generation layer formed between the stacks, the charge generation layer comprising an N type charge generation layer and a P type charge generation layer to adjust the charge balance between the respective stacks,
The P type charge generating layer may include a first organic material including a heterocyclic ring compound including at least one electron drag substituent among CN, NO ₂ , F, Cl, Br, and I, and at least one aromatic amine It is formed of a second organic material containing (Aromatic Amine),
The second organic material mixed with the first organic material to form the P-type charge generating layer has a volume ratio of 15 to 35%,
The N type charge generating layer is an organic light emitting device in which an alkali metal or an alkaline earth metal is doped into an organic material including a heterocyclic ring including N. delete The method of claim 1,
The first organic material is an organic light emitting device represented by the following [Formula 1]:
[Formula 1]

. The method of claim 1,
The second organic material is selected from any one of the following [Formula 2-1], [Formula 2-2], [Formula 2-3],
[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-1], [Formula 2-2], [Formula 2-3] R1, R2, R3, R4, R5, R6, R7, R8 are selected from C ₆ ~ C ₂₀ aromatic group, R9 , R10 is hydrogen, selected from C ₆ ~ C ₂₀ aromatic group, having at least one N, S, P element, an organic light emitting device selected from C ₃ ~ C ₁₇ heterocyclic compound. delete delete delete The method of claim 1,
The amine contained in the aromatic amine has at least one nitrogen of 6 or less, and the aromatic contained in the aromatic amine has 6 to 40 carbon atoms of the aromatic ring. Organic light emitting device. The method of claim 8,
The aromatic ring is a phenyl (Phenyl), phenyl (Phenyl) derivatives, naphthyl (Naphthyl), naphthyl (Naphthyl) derivatives, anthracene (Anthrancene), anthracene derivatives (Pyrene), pi An organic light emitting device selected from at least one of a styrene derivative, a perylene derivative, and a perylene derivative. The method of claim 1,
The N-type charge generating layer is an organic light emitting device having 20 to 60 carbon atoms containing a heterocyclic ring containing N. The method of claim 1,
The alkali metal is selected from Li, Na, K, Rb, Cs, Fr and Yb, and the alkaline earth metal is selected from Be, Mg, Ca, Sr, Ba, and Ra. The method of claim 1,
The alkaline earth metal or the alkali metal is doped at 0.5% to 10% based on the volume of the N-type charge generating layer. The method of claim 1,
The N-type charge generating layer is formed of a compound having a core of pyrene (Pyrene) including a heterocyclic ring containing N, and the following [Formula 3-1] to [Formula 3-5] Selected from at least one pyrene compound,
[Formula 3-1] [Formula 3-2]

[Formula 3-3] [Formula 3-4] [Formula 3-5]

R1, R2, R3, and R4 of [Formula 3-1] to [Formula 3-5] are each independently selected from [Formula 4-1] to [Formula 4-72], and the R1, R2 and R3 , R4 is different or the same organic light emitting device.
[Formula 4-1] [Formula 4-2] [Formula 4-3]

[Formula 4-4] [Formula 4-5] [Formula 4-6]

.

[Formula 4-7] [Formula 4-8] [Formula 4-9]

[Formula 4-10] [Formula 4-11] [Formula 4-12]

[Formula 4-13] [Formula 4-14]

[Formula 4-15] [Formula 4-16]

[Formula 4-17] [Formula 4-18]

[Formula 4-19] [Formula 4-20]

[Formula 4-21] [Formula 4-22]

[Formula 4-23] [Formula 4-24]

[Formula 4-25] [Formula 4-26]

[Formula 4-27] [Formula 4-28]

[Formula 4-29] [Formula 4-30] [Formula 4-31]

[Formula 4-32] [Formula 4-33]

[Formula 4-34] [Formula 4-35] [Formula 4-36]

[Formula 4-37] [Formula 4-38]

[Formula 4-39] [Formula 4-40]

[Formula 4-41] [Formula 4-42] [Formula 4-43]

[Formula 4-44] [Formula 4-45]

[Formula 4-46] [Formula 4-47] [Formula 4-48]

[Formula 4-49] [Formula 4-50]

[Formula 4-51] [Formula 4-52]

[Formula 4-53] [Formula 4-54] [Formula 4-55]

[Formula 4-56] [Formula 4-57]

[Formula 4-58] [Formula 4-59] [Formula 4-60]

[Formula 4-61] [Formula 4-62]

[Formula 4-63] [Formula 4-64]

[Formula 4-65] [Formula 4-66]

[Formula 4-67] [Formula 4-68]

[Formula 4-69] [Formula 4-70]

[Formula 4-71] [Formula 4-72]

delete A driving thin film transistor formed on the substrate;
A first electrode connected to the driving thin film transistor;
A plurality of stacks stacked on the first electrode and including a light emitting layer to emit specific light;
A charge generation layer formed between the stacks, the charge generation layer comprising an N type charge generation layer and a P type charge generation layer to adjust the charge balance between the stacks;
A second electrode formed on the stacks;
The P type charge generating layer may include a first organic material including a heterocyclic ring compound including at least one electron drag substituent among CN, NO ₂ , F, Cl, Br, and I, and at least one aromatic amine It is formed of a second organic material containing (Aromatic Amine),
The second organic material mixed with the first organic material to form the P-type charge generating layer has a volume ratio of 15 to 35%,
The N-type charge generating layer is an organic light emitting display device in which an alkali metal or an alkaline earth metal is doped into an organic material including a heterocyclic ring including N. delete The method of claim 15,
The first organic material is an organic light emitting display device represented by the following [Formula 1]:
[Formula 1]

. The method of claim 15,
The second organic material is selected from any one of the following [Formula 2-1], [Formula 2-2], [Formula 2-3],
[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-1], [Formula 2-2], [Formula 2-3] R1, R2, R3, R4, R5, R6, R7, R8 are selected from C ₆ ~ C ₂₀ aromatic group, R9 , R 10 is hydrogen, is selected from C ₆ ~ C ₂₀ aromatic group, has at least one element N, S, P, and is selected from C ₃ ~ C ₁₇ heterocyclic compound. delete delete delete The method of claim 15,
The amine contained in the aromatic amine has at least one nitrogen of 6 or less, and the aromatic contained in the aromatic amine has 6 to 40 carbon atoms of the aromatic ring. OLED display. The method of claim 22,
The aromatic ring is a phenyl (Phenyl), phenyl (Phenyl) derivatives, naphthyl (Naphthyl), naphthyl (Naphthyl) derivatives, anthracene (Anthrancene), anthracene derivatives (Pyrene), pi An organic light emitting display device selected from at least one of a styrene derivative, a perylene derivative, and a perylene derivative. The method of claim 15,
The N-type charge generating layer has an organic light emitting display device having 20 to 60 carbon atoms including a heterocyclic ring including N. The method of claim 15,
The alkali metal is selected from Li, Na, K, Rb, Cs, Fr, and Yb, and the alkaline earth metal is selected from Be, Mg, Ca, Sr, Ba, and Ra. The method of claim 15,
The alkaline earth metal or the alkali metal is doped at 0.5% to 10% based on the volume of the N-type charge generating layer. The method of claim 15,
The N-type charge generating layer is formed of a compound having a core of pyrene (Pyrene) including a heterocyclic ring containing N, and the following [Formula 3-1] to [Formula 3-5] Selected from at least one pyrene compound,
[Formula 3-1] [Formula 3-2]

[Formula 3-3] [Formula 3-4] [Formula 3-5]

R1, R2, R3, and R4 of [Formula 3-1] to [Formula 3-5] are each independently selected from [Formula 4-1] to [Formula 4-72], and the R1, R2 and R3 , R4 is different or the same organic light emitting display device.
[Formula 4-1] [Formula 4-2] [Formula 4-3]

[Formula 4-4] [Formula 4-5] [Formula 4-6]

.

[Formula 4-7] [Formula 4-8] [Formula 4-9]

[Formula 4-10] [Formula 4-11] [Formula 4-12]

[Formula 4-13] [Formula 4-14]

[Formula 4-15] [Formula 4-16]

[Formula 4-17] [Formula 4-18]

[Formula 4-19] [Formula 4-20]

[Formula 4-21] [Formula 4-22]

[Formula 4-23] [Formula 4-24]

[Formula 4-25] [Formula 4-26]

[Formula 4-27] [Formula 4-28]

[Formula 4-29] [Formula 4-30] [Formula 4-31]

[Formula 4-32] [Formula 4-33]

[Formula 4-34] [Formula 4-35] [Formula 4-36]

[Formula 4-37] [Formula 4-38]

[Formula 4-39] [Formula 4-40]

[Formula 4-41] [Formula 4-42] [Formula 4-43]

[Formula 4-44] [Formula 4-45]

[Formula 4-46] [Formula 4-47] [Formula 4-48]

[Formula 4-49] [Formula 4-50]

[Formula 4-51] [Formula 4-52]

[Formula 4-53] [Formula 4-54] [Formula 4-55]

[Formula 4-56] [Formula 4-57]

[Formula 4-58] [Formula 4-59] [Formula 4-60]

[Formula 4-61] [Formula 4-62]

[Formula 4-63] [Formula 4-64]

[Formula 4-65] [Formula 4-66]

[Formula 4-67] [Formula 4-68]

[Formula 4-69] [Formula 4-70]

[Formula 4-71] [Formula 4-72]

delete

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