JP4954457B2 - Method for manufacturing light emitting device - Google Patents

Description

  The present invention relates to a light emitting device using an electroluminescent material capable of oscillating laser light.

  A semiconductor laser has a merit that a laser oscillator can be remarkably reduced in size and weight as compared with other gas or solid-state lasers, and is a light source for transmitting and receiving signals by optical interconnection in an optical integrated circuit. As a light source for recording on a recording medium such as an optical disk or an optical memory, and as a light source for optical communication using an optical fiber or the like as an optical waveguide, it has been put to practical use in various fields. The oscillation wavelengths of semiconductor lasers range widely from blue to infrared. Generally, semiconductor lasers that are put into practical use include, for example, GaAs lasers (wavelength 0.84 μm), InAs lasers (wavelength 3.11 μm), and InSb. In many cases, such as a laser (wavelength: 5.2 μm), GaAlAs (wavelength: 0.72 μm to 0.9 μm), and InGaAsP (wavelength: 1.0 μm to 1.7 μm), the oscillation wavelength exists in the infrared region.

  In recent years, there have been many studies on the practical application of semiconductor lasers having an oscillation wavelength in the visible region. From this trend, laser light is oscillated using an electroluminescent material that can obtain luminescence by applying an electric field. Attention is being focused on laser oscillators (organic semiconductor lasers) that can be used. Since an organic semiconductor laser can obtain laser light having a wavelength in the visible region and can be manufactured on an inexpensive glass substrate, various uses are expected.

The following Patent Document 1 describes an organic semiconductor laser having a peak wavelength λ of 510 nm.
JP 2000-156536 A (page 11)

  However, laser light oscillated from an organic semiconductor laser generally has a lower directivity than other lasers and tends to diffuse. If the directivity of the laser beam is lowered, signal transmission / reception in the optical interconnection becomes unstable due to disclination, which causes a problem that high integration of the optical integrated circuit is hindered. Further, when the diffusion of the laser beam is significant, it is difficult to ensure the energy density of the laser beam. It is possible to secure a desired energy density by either increasing the intensity of the laser light oscillated from the light source or reducing the distance between the light source of the laser light and the predetermined region. However, the former has a demerit that power consumption increases, and the latter has a demerit that the use of the organic semiconductor laser is limited.

  In addition, it is possible to improve the directivity of laser light by installing a separately prepared optical system in the organic semiconductor laser serving as the light source. However, the more complicated the optical system, the more complicated the adjustment of the optical system at the time of maintenance and the alignment between the optical system and the organic semiconductor laser, and the poorer the resistance to physical impact.

  In view of the above-described problems, the present invention can increase the directivity of the oscillated laser light and can increase the resistance to physical shock, and the light emitting device represented by a laser oscillator using an electroluminescent material. The issue is to provide

  In the light emitting device of the present invention, one or both of the reflectors for reflecting the stimulated emission light have a curvature, and the two reflectors face each other so that an unstable resonator is formed. Laser light that is close to one mode and has high directivity is obtained. The center of curvature of the reflective material may be provided on the side on which the other reflective material is formed, or may be provided on the opposite side to the other reflective material. Note that the curvature is defined as positive if the reflective material is concave toward the inside of the resonator. Similarly, if the reflective material is convex toward the inside of the resonator, the curvature is defined as negative.

  Specifically, the light emitting device of the present invention includes a first reflective material having a convex portion or a concave portion, a light emitting element formed on the first reflective material so as to overlap the convex portion or the concave portion, and the light emitting element. And a second reflective material overlapping the first reflective material. The light-emitting element has a first electrode (anode), a second electrode (cathode), and a light-emitting layer provided between the two electrodes. In the present invention, an electric field included in the light-emitting layer is included. The light emitting material functions as a laser medium. A hole injection layer, a hole transport layer, and the like may be provided between the light emitting layer and the anode, and an electron injection layer, an electron transport layer, and the like may be provided between the light emitting layer and the cathode. In this case, all layers provided between the anode and the cathode including the light emitting layer are called electroluminescent layers. In some cases, the layer constituting the electroluminescent layer contains an inorganic compound.

  In the present invention, as described above, two reflecting materials may be separately provided in addition to the light emitting element, but one or both of the electrodes of the light emitting element may be used as the reflecting material. Alternatively, a layer other than the light-emitting layer included in the electroluminescent layer, for example, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, or the like is used as a reflective material, and light generated in the light-emitting layer is reflected, and an optical resonator May be formed. Laser light is oscillated by resonating light emitted from the electroluminescent material by the two reflecting materials.

  In addition, the optical resonator included in the light emitting device of the present invention is an unstable resonator, and adjusts the radius of curvature r and the length of the resonator L, or controls the position of the center of curvature of the unevenness of the reflector. Therefore, an unstable resonator can be formed and directivity can be improved. In addition, if the unstable resonator has a high gain, the mode volume (the product of the area obtained from the spot diameter on the reflecting mirror surface and the resonator length) can be increased, so that the laser output can be increased. The term “stable / unstable” here does not mean whether the output from the laser is stable or unstable.

  Note that, unlike an organic semiconductor laser, a semiconductor laser using a single crystal semiconductor forms a curved surface on an electrode functioning as a reflecting material, or forms an active region that is a laser medium on a reflecting material having a curved surface. This is difficult in the manufacturing process. In addition, when a reflective material having a curved surface formed separately is attached after forming an active region that is a laser medium, position control between the two reflective materials and the active region must be performed on the order of several tens of nanometers. Therefore, the manufacturing process becomes complicated. However, in the case of an organic semiconductor laser, it is relatively easy to form a curved surface on an electrode functioning as a reflective material, and to form a light emitting element on a reflective material having a curved surface, as compared to a semiconductor laser. Therefore, it is possible to relatively easily control the position of the two reflecting materials and the active region on the order of several tens of nanometers depending on the film thickness of each layer.

  According to the above-described configuration, the present invention can increase the oscillation efficiency of single-mode laser light, and thus can improve the directivity of laser light without providing an optical system separately. Unlike the case where an optical system is provided separately, it is possible to avoid the trouble of adjusting the optical system at the time of maintenance and aligning the optical system with the organic semiconductor laser, and tolerating the physical shock of the laser oscillator. Can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 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 this embodiment mode.

  An embodiment of the laser oscillator of the present invention will be described with reference to FIG. 1A is a cross-sectional view of the laser oscillator of the present invention, and FIG. 1B is a top view of the laser oscillator shown in FIG. A cross-sectional view taken along A-A ′ in FIG. 1B corresponds to FIG. The laser oscillator of the present invention shown in FIG. 1 includes a substrate 101 having a convex portion 100 and a light emitting element 102 formed on the substrate 101 so as to overlap the convex portion 100. The convex portion 100 has a curved surface, and the center of curvature of the curved surface exists on the side of the substrate 101 opposite to the light emitting element 102.

  Note that FIG. 1A illustrates an example in which the light-emitting element 102 is directly formed over the substrate 101; however, the present invention is not limited to this structure. One or a plurality of other films such as an insulating film and a film for reflecting light (reflection film) may be formed between the substrate 101 and the light emitting element 102. In FIG. 1A, the substrate 101 having the convex portion 100 is used, but the convex portion may be formed using a film different from the substrate over a flat substrate.

  FIG. 10 shows an example in which a convex portion 1102 is formed on a flat substrate 1101 using a droplet discharge method. Reference numeral 1103 denotes a nozzle of the droplet discharge device. For example, the convex portion 100 of FIG. 1 may be formed using a droplet discharge method as shown in FIG.

  As the substrate 101, glass, quartz, metal, bulk semiconductor, plastic, or the like can be used.

  The light-emitting element 102 includes an electrode 103 formed over the substrate 101, an electroluminescent layer 104 formed over the electrode 103, and an electrode 105 formed over the electroluminescent layer 104 so as to overlap the electrode 103. . The electrode 103 formed on the substrate 101 has a curved surface formed by the convex portion 100 of the substrate 101, and the center of curvature of the curved surface exists on the substrate 101 side.

  One of the electrodes 103 and 105 is an anode and the other is a cathode. Although FIG. 1 shows an example in which the electrode 103 is an anode and the electrode 105 is a cathode, the electrode 103 may be a cathode and the electrode 105 may be an anode. By applying a forward bias voltage between the electrodes 103 and 105, current is supplied to the electroluminescent layer 104, and the electroluminescent layer 104 can emit light.

  In the laser oscillator illustrated in FIG. 1, an optical resonator is formed by using the electrodes 103 and 105 included in the light emitting element 102 as a reflecting material. The light emitted from the electroluminescent layer 104 is resonated by the electrodes 103 and 105 and oscillated from the electrode 105 side as laser light.

  FIG. 2 shows a state in which a forward bias voltage is applied between the electrodes 103 and 105 in the laser oscillator shown in FIG. By applying a voltage between the electrodes 103 and 105, the light generated in the electroluminescent layer 104 is resonated. Assuming that the electrode 105 has a flat surface, this optical resonator is an unstable resonator. Therefore, the distance L between the electrodes 103 and 105 corresponding to the resonator length and the focal length f of the curved surface of the electrode 103 satisfy f <0. Note that since twice the focal length f corresponds to the radius of curvature r, it can be said that r <L. The cavity length is assumed to correspond to the distance between the two reflectors on the extension of the optical path of the oscillated laser beam. With the above structure, single-mode laser light can be easily obtained from laser light oscillated from the electrode 105 side, and thus the oscillation efficiency of the single-mode laser light can be increased. As indicated by the dashed arrow, laser light is oscillated from the electrode 105 side to the opposite side of the substrate 101 by applying a voltage between the electrodes 103 and 105. Although not shown, laser light may be oscillated toward the substrate 101 side.

  When the electrode 105 has a curved surface and the center of curvature of the curved surface exists on the electrode 103 side, in order to form an unstable resonator, the resonator length L and the radius of curvature r1 of the electrode 103 (r1 <0). ), The curvature radius r2 (r2> 0) of the electrode 105 needs to satisfy at least one of the following two expressions.

  Here, the following nine cases can be considered as the relationship between the curvature radii r1 and r2 satisfying the above equation 1 and the resonator length L. (1) r1 <0, r2 <0 (both reflectors have convex portions, and the respective radii of curvature r1 and r2 are both negative) (2) r1 <0, 0 <r2 <L (reflector (1) has a convex portion, the radius of curvature r1 is negative, and the other reflector has a concave portion, and the radius of curvature r2 is smaller and positive than the resonator length). (3) r1 < 0, r2> L + | r1 | (one of the reflectors has a convex part, the radius of curvature r1 is negative, the other reflector has a concave part, and the radius of curvature r2 is L + | r1 | (4) 0 <r1 <L, r2 <0 (one of the reflectors has a recess, its radius of curvature r1 is larger than the resonator length L, and the other reflector r2 has a projection) (5) r1> L + | r2 |, r2 <0 (one of the reflectors has a recess, and its radius of curvature r1 is L + larger than r2 |, the other reflector has a convex portion, and its radius of curvature r2 is negative) (6) 0 <r1 <L, r2> L (both reflectors have a concave portion, (7) 0 <r1 <L−r2, 0 <r2 <L / 2 (both reflectors) (7) 0 <r1 <L−r2, 0 <r2 <L / 2 Both have a recess, and one radius of curvature r1 is smaller and positive than (resonator length L−the other radius of curvature r2), and r2 is smaller than L / 2 and positive) (8) r1> L , 0 <r2 <L (both reflectors have a recess, one radius of curvature r1 is larger than the resonator length L, and the other radius of curvature r2 is smaller than L and positive) (9) 0 < r1 <L / 2, 0 <r2 <L-r1 (both reflectors have recesses, one radius of curvature r1 is the resonator length The radius of curvature r2 is smaller and positive than half of L, and the other radius of curvature r2 is smaller and positive than (L-r1). The unstable resonator is determined by selecting the radius of curvature of the reflector used in the optical resonator, the position of the center of curvature, and the resonator length.

  Note that although FIGS. 1 and 2 illustrate a mode in which a single-mode laser light oscillation efficiency is increased using a reflective material having a convex portion, a reflective material having a concave portion may be used. The form of the laser oscillator of the present invention using a reflective material having a recess will be described with reference to FIG.

  FIG. 3 is a sectional view of the laser oscillator of the present invention. As shown in FIG. 3, the laser oscillator of the present invention includes a substrate 201 having a recess 200 and a light emitting element 202 formed on the substrate 201 so as to overlap the recess 200. As the substrate 201, glass, quartz, metal, bulk semiconductor, plastic, or the like can be used.

  Note that FIG. 3 illustrates an example in which the light-emitting element 202 is directly formed over the substrate 201; however, the present invention is not limited to this structure. One or more other films such as an insulating film or a film for reflecting light (reflection film) may be formed between the substrate 201 and the light emitting element 202. In FIG. 3, the substrate 201 having the recess 200 is used, but the recess may be formed on a flat substrate using a film different from the substrate.

  The concave portion 200 has a curved surface, and the center of curvature of the curved surface exists on the light emitting element 202 side.

  The light-emitting element 202 includes an electrode 203 formed over the substrate 201, an electroluminescent layer 204 formed over the electrode 203, and an electrode 205 formed over the electroluminescent layer 204 so as to overlap the electrode 203. . One of the electrodes 203 and 205 is an anode and the other is a cathode. Although FIG. 3 shows an example in which the electrode 203 is an anode and the electrode 205 is a cathode, the electrode 203 may be a cathode and the electrode 205 may be an anode. By applying a forward bias voltage between the electrodes 203 and 205, current is supplied to the electroluminescent layer 204, and the electroluminescent layer 204 can emit light.

  In the laser oscillator shown in FIG. 3, an optical resonator is formed by the electrodes 203 and 205 included in the light emitting element 202 in the same manner as the laser oscillator shown in FIG. Light emitted from the electroluminescent layer 204 is resonated by the electrodes 203 and 205, and is oscillated from the electrode 205 side as laser light. Note that laser light may be oscillated toward the substrate 201 side.

  The optical resonator formed by the electrodes 203 and 205 is an unstable resonator. In order to form an unstable resonator in the case of FIG. 3, the distance L between the electrodes 203 and 205 corresponding to the resonator length and the focal length f (f> 0) of the curved surface of the electrode 203 are f> (L + r2). It is necessary to satisfy / 2.

  When the electrode 205 has a convex curved surface and the center of curvature of the curved surface exists on the opposite side of the electrode 203, the resonator length L and the curvature of the electrode 203 are formed in order to form an unstable resonator. The radius r1 (r1> 0) and the radius of curvature r2 (r2 <0) of the electrode 205 need to satisfy at least one of the two expressions shown in the above equation 1. With the above structure, it becomes easier to obtain single-mode laser light among the laser light oscillated from the electrode 205 side, and thus the oscillation efficiency of the single-mode laser light can be increased.

  Note that in FIGS. 1 to 3, the two electrodes included in the light-emitting element are used as the reflective material, but the present invention is not limited to this structure. In addition to the light emitting element, two additional reflecting materials may be provided, or one of the electrodes of the light emitting element may be used as the reflecting material, and one additional reflecting material may be provided. Alternatively, a layer other than the light-emitting layer included in the electroluminescent layer, for example, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, or the like is used as a reflective material, and light generated in the light-emitting layer is reflected, and an optical resonator May be formed.

  In this example, a structure of a light emitting element used in the laser oscillator of the present invention will be described.

  FIG. 5 shows one mode of an element structure of a light-emitting element used in the present invention. The light emitting element shown in FIG. 5 has a structure in which an electroluminescent layer 408 is sandwiched between an anode 401 and a cathode 407. The electroluminescent layer 408 includes a hole injection layer 402, a hole transport layer 403, a light emitting layer 404, an electron transport layer 405, and an electron injection layer 406, which are sequentially stacked from the anode 401 side.

  Note that the light-emitting element used in the laser oscillator of the present invention only needs to include at least a light-emitting layer in the electroluminescent layer. Layers having functions other than light emission (a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer) can be appropriately combined. Specific examples of materials that can be used for each of the above layers are given below. However, materials applicable to the present invention are not limited to these.

  As the anode 401, a conductive material having a high work function is preferably used. When light is transmitted through the anode 401, a highly light-transmitting material is used. In this case, a transparent conductive material such as indium-tin oxide (ITO), indium-zinc oxide (IZO), or indium-tin oxide containing silicon oxide (ITSO) may be used. When the anode 401 is used as a reflecting material, a material that can reflect light is used. In this case, for example, in addition to a single layer film made of one or more of TiN, ZrN, Ti, W, Ni, Pt, Cr, Ag, etc., a laminate of titanium nitride and a film mainly composed of aluminum, a titanium nitride film For example, a three-layer structure of a film mainly containing aluminum and a titanium nitride film can be used. Alternatively, the above-described transparent conductive material may be stacked over the material that can reflect light, and used as the anode 401.

  As a hole injection material that can be used for the hole injection layer 402, a material having a relatively small ionization potential and a small absorption in the visible light region is preferable. Broadly divided into metal oxides, low-molecular organic compounds, and high-molecular organic compounds. As the metal oxide, for example, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, or the like can be used. If it is a low molecular weight organic compound, for example, a starburst amine typified by m-MTDATA, a metal phthalocyanine typified by copper phthalocyanine (abbreviation: Cu-Pc), phthalocyanine (abbreviation: H2-Pc), 2, 3 -A dioxyethylene thiophene derivative etc. can be used. A film in which a low molecular organic compound and the metal oxide are co-evaporated may be used. As a high molecular organic compound, for example, a polymer such as polyaniline (abbreviation: PAni), polyvinyl carbazole (abbreviation: PVK), or a polythiophene derivative can be used. Polyethylene dioxythiophene (abbreviation: PEDOT), which is one of polythiophene derivatives, doped with polystyrene sulfonic acid (abbreviation: PSS) may be used.

  As a hole transport material that can be used for the hole transport layer 403, a known material that has high hole transportability and low crystallinity can be used. Aromatic amine-based compounds (that is, those having a benzene ring-nitrogen bond) are preferred, for example, 4,4-bis [N- (3-methylphenyl) -N-phenylamino] biphenyl (TPD) And 4,4′-bis [N- (1-naphthyl) -N-phenyl-amino] biphenyl (α-NPD) which is a derivative thereof. Starburst aromatic amine compounds such as 4,4 ', 4 "-tris (N, N-diphenylamino) triphenylamine (TDATA) and MTDATA can also be used. Alternatively, 4,4 ′, 4 ″ -tris (N-carbazolyl) triphenylamine (abbreviation: TCTA) may be used. As the polymer material, poly (vinyl carbazole) or the like showing good hole transportability can be used. Further, an inorganic material such as MoOx may be used.

  A known material can be used for the light emitting layer 404. For example, tris (8-quinolinolato) aluminum (Alq3), tris (4-methyl-8-quinolinolato) aluminum (Almq3), bis (10-hydroxybenzo [η] -quinolinato) beryllium (BeBq2), bis (2-methyl) -8-quinolinolato)-(4-hydroxy-biphenylyl) -aluminum (BAlq), bis [2- (2-hydroxyphenyl) -benzoxazolate] zinc (Zn (BOX) 2), bis [2- (2 Metal complexes such as -hydroxyphenyl) -benzothiazolate] zinc (Zn (BTZ) 2) can be used. Various fluorescent dyes (coumarin derivatives, quinacridone derivatives, rubrene, 4,4-dicyanomethylene, 1-pyrone derivatives, stilbene derivatives, various condensed aromatic compounds, etc.) can also be used. Phosphorescent materials such as platinum octaethylporphyrin complex, tris (phenylpyridine) iridium complex, tris (benzylideneacetonato) phenanthrene europium complex can also be used. In particular, phosphorescent materials have a longer excitation lifetime than fluorescent materials, so it is easy to create an inversion distribution that is essential for laser oscillation, that is, a state in which the number of molecules in the excited state is larger than the number of molecules in the ground state. Become. The above materials can be used both as a dopant and as a single layer film.

  As a host material used for the light-emitting layer 404, a hole transport material or an electron transport material typified by the above example can be used. Alternatively, a bipolar material such as 4,4′-N, N′-dicarbazolylbiphenyl (abbreviation: CBP) can be used.

  As an electron transporting material that can be used for the electron transporting layer 405, a metal complex having a quinoline skeleton or a benzoquinoline skeleton represented by Alq3, a mixed ligand complex thereof, or the like can be used. Specifically, metal complexes such as Alq 3, Almq 3, BeBq 2, BAlq, Zn (BOX) 2, and Zn (BTZ) 2 can be mentioned. In addition to metal complexes, 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 1,3-bis [5- (p Oxadiazole derivatives such as -tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5 -(4-biphenylyl) -1,2,4-triazole (TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2, Triazole derivatives such as 4-triazole (p-EtTAZ), imidazole derivatives such as TPBI, phenanthroyl such as bathophenanthroline (BPhen) and bathocuproin (BCP) It can be used derivatives.

  As the electron injecting material that can be used for the electron injecting layer, the above-described electron transporting material can be used. In addition, an ultra-thin film of an insulator such as an alkali metal halide such as LiF or CsF, an alkaline earth halide such as CaF2, or an alkali metal oxide such as Li2O is often used. In addition, alkali metal complexes such as lithium acetylacetonate (abbreviation: Li (acac) and 8-quinolinolato-lithium (abbreviation: Liq) are also effective.

  For the cathode 407, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a low work function as used in a normal light emitting element can be used. Specifically, in addition to alkaline metals such as Li and Cs, alkaline earth metals such as Mg, Ca and Sr, and alloys containing these (Mg: Ag, Al: Li, etc.), rare earths such as Yb and Er It can also be formed using a metal. When an electron injection layer such as LiF, CsF, CaF2, or Li2O is used, a normal conductive thin film such as aluminum can be used. When light is transmitted through the cathode 407, an ultrathin film containing an alkali metal such as Li or Cs and an alkaline earth metal such as Mg, Ca, or Sr, and a transparent conductive film (ITO, ITSO, IZO, ZnO, or the like) ) And a stacked structure may be used. Alternatively, an electron injection layer in which an alkali metal or an alkaline earth metal and an electron transport material are co-evaporated may be formed, and a transparent conductive film (ITO, ITSO, IZO, ZnO, or the like) may be stacked thereon.

  The optical resonator allows laser light to oscillate from the reflective material having the higher transmittance by setting one of the two reflecting materials to have as high a reflectance as possible and the other having a certain degree of transmittance. Can do. For example, when the anode 401 and the cathode 407 are used as reflecting materials on the laser light oscillation side, the material or film thickness is selected so that the transmittance is about 5 to 70%. In the case where a reflective material is separately formed, a material that transmits light in the anode 401 or the cathode 407 is selected.

  The interval between the reflectors is set to an integral multiple of half the wavelength λ to be resonated. And the laminated structure of a light emitting element is designed so that the light reflected in a reflecting material and the phase of the newly emitted light may correspond.

  Note that in manufacturing the light-emitting element of the present invention described above, the stacking method of each layer in the light-emitting element is not limited. As long as lamination is possible, any method such as a vacuum deposition method, a spin coating method, an ink jet method, or a dip coating method may be selected.

  In this example, one mode of a laser oscillator of the present invention using a plurality of light emitting elements will be described.

  FIG. 6A shows a top view of the laser oscillator of this example at the time when the anode of the light emitting element is manufactured. FIG. 6B is a cross-sectional view taken along line A-A ′ in FIG. In the laser oscillator of this embodiment, a reflective film 602 is formed on a substrate 601 having a plurality of protrusions 600 so as to overlap the plurality of protrusions 600. The reflective film 602 can reflect light emitted from the light-emitting element and can be formed using an insulating material. For example, a film in which insulating films having different refractive indexes such as silicon oxide, silicon nitride, and titanium oxide are alternately stacked may be used.

  An anode 603 is formed on the reflective film 602 so as to overlap the plurality of convex portions 600. The anode 603 is formed using a light-transmitting material. In FIG. 6, the anode 603 has translucency and the reflective film 602 is used as a reflective material, but this embodiment is not limited to this mode. The anode 603 may be formed of a material that reflects light without providing the reflective film 602.

  Next, FIG. 7A shows a top view of the laser oscillator of this example at the time when the light emitting element is completed. FIG. 7B is a cross-sectional view taken along line A-A ′ in FIG. In FIG. 7, electroluminescent layers 604 a to 604 c corresponding to three colors of red (R), green (G), and blue (B) are formed on the anode 603 so as to overlap with the plurality of convex portions 600. . In FIG. 7A, the electroluminescent layers 604a to 604c are formed separately, but may be formed so as to partially overlap each other. In addition, a cathode 605 is formed on the electroluminescent layers 604a to 604c so as to overlap the plurality of convex portions 600.

  In this embodiment, an arbitrary cathode 605 partially overlaps all the anodes 603. The overlapping portion corresponds to the light emitting element 606, and each light emitting element 606 is located on the convex portion 600. Then, the transmittance of the cathode 605 is set to about 5 to 70%, and the light generated in the electroluminescent layers 604a to 604c resonates between the reflective film 602 functioning as a reflector and the cathode 605, and is oscillated from the cathode 605 side. Like that. The optical resonator formed by the reflective film 602 and the cathode 605 is an unstable resonator, so that the directivity of the laser light oscillated from the cathode 605 side is improved. The laser oscillator of this embodiment can oscillate laser light by using the selected light emitting element 606 by controlling the voltage applied to the anode 603 and the cathode 605 as in the passive matrix light emitting device.

  In this embodiment, the anode 603 and the cathode 605 may be interchanged. However, in this case, since the anode 603 functions as a reflecting material, it is formed of a material that can reflect light.

  In this embodiment, the mode of increasing the oscillation efficiency of single-mode laser light using a reflective material having a convex portion has been described. However, a reflective material having a concave portion may be used. In this embodiment, the embodiment in which the substrate 601 has unevenness is described. However, the unevenness may be formed on a flat substrate by using a film different from the substrate. Note that the laser oscillator (light emitting device) of this embodiment may be used as a display device. Further, by providing a driving element for each light emitting element, the laser oscillator of this embodiment may be an active matrix display device. The display device provided with the laser oscillator of this embodiment includes a projector and the like.

  In this embodiment, electroluminescent layers corresponding to R, G, and B are provided. However, when performing monochrome display, only one electroluminescent layer is required.

  This embodiment can be implemented in combination with the first embodiment.

  In this embodiment, a mode in which a reflection film capable of reflecting light is formed between a substrate and a light emitting element in the laser oscillator shown in FIG.

  FIG. 4A shows a cross-sectional view of the laser oscillator of this embodiment. As shown in FIG. 4A, in the laser oscillator of this embodiment, a reflective film 802 is formed on a substrate 801 having a convex portion 800 so as to overlap the convex portion 800. The reflective film 802 can be formed of a material that can reflect light. For example, a material including one or more metal elements such as Al, Ag, Ti, W, Pt, and Cr is used, and an evaporation method is used. Can be formed. Note that the reflective film is not limited to the above materials, and may be any film that can reflect light. For example, a film in which insulating films having different refractive indexes such as silicon oxide, silicon nitride, and titanium oxide are alternately stacked may be used as the reflective film.

  Further, a light emitting element 803 is formed on the reflective film 802 so as to overlap the convex portion 800. The light-emitting element 803 includes an electrode 804 formed over the reflective film 802, an electroluminescent layer 805 formed over the electrode 804, and an electrode 806 formed over the electroluminescent layer 805 so as to overlap the electrode 804. .

  The substrate 801 has a curved surface at the convex portion 800, and the center of curvature of the curved surface exists on the opposite side of the light emitting element 803 on the substrate 801.

  One of the electrodes 804 and 806 is an anode and the other is a cathode. Although FIG. 4 shows an example in which the electrode 804 is an anode and the electrode 806 is a cathode, the electrode 804 may be a cathode and the electrode 806 may be an anode. By applying a forward bias voltage between the electrodes 804 and 806, current is supplied to the electroluminescent layer 805, and the electroluminescent layer 805 can emit light. In FIG. 4A, the electrode 804 has a light-transmitting property, and the reflective film 802 and the electrode 806 function as a reflective material. Therefore, light emitted from the electroluminescent layer 805 is resonated by the electrodes 804 and 806 and oscillated from the electrode 806 side as laser light. Note that laser light may be oscillated toward the substrate 801 side.

  FIG. 4B shows a cross-sectional view of the laser oscillator of this example. As shown in FIG. 4B, in the laser oscillator of this embodiment, a reflective film 812 having a convex portion 810 is formed on a flat substrate 811. The reflective film 812 can be formed using a material that can reflect light. For example, a material containing one or more metal elements such as Al, Ag, Ti, W, Pt, and Cr can be used. . Note that the reflective film is not limited to the above materials, and may be any film that can reflect light.

  Further, a light emitting element 813 is formed on the reflective film 812 so as to overlap the convex portion 810. The light-emitting element 813 includes an electrode 814 formed over the reflective film 812, an electroluminescent layer 815 formed over the electrode 814, and an electrode 816 formed over the electroluminescent layer 815 so as to overlap the electrode 814. .

  The reflective film 812 has a curved surface at the convex portion 810, and the center of curvature of the curved surface exists on the opposite side of the light emitting element 813 on the reflective film 812.

  One of the electrodes 814 and 816 is an anode and the other is a cathode. Although FIG. 4 shows an example in which the electrode 814 is an anode and the electrode 816 is a cathode, the electrode 814 may be a cathode and the electrode 816 may be an anode. By applying a forward bias voltage between the electrodes 814 and 816, current is supplied to the electroluminescent layer 815, and the electroluminescent layer 815 can emit light. In FIG. 4B, the electrode 814 has a light-transmitting property, and the reflective film 812 and the electrode 816 function as a reflective material. Therefore, light emitted from the electroluminescent layer 815 is resonated by the electrodes 814 and 816 and oscillated from the electrode 816 side as laser light. Note that laser light may be oscillated toward the substrate 811 side.

  This embodiment can be implemented in combination with Embodiment 1 or 2.

  In this embodiment, a mode of forming a film having a convex portion in the laser oscillator shown in FIG. 8 will be described.

  FIG. 8 is a sectional view of the laser oscillator of this embodiment. As shown in FIG. 8, the laser oscillator of this embodiment includes a substrate 821 having a recess 820 and a light emitting element 822 formed on the substrate 821 so as to overlap the recess 820. As the substrate 821, glass, quartz, metal, bulk semiconductor, plastic, or the like can be used.

  Note that FIG. 8 illustrates an example in which the light-emitting element 822 is directly formed over the substrate 821, but the present invention is not limited to this structure. One or more other films such as an insulating film or a film for reflecting light (reflection film) may be formed between the substrate 821 and the light-emitting element 822. In FIG. 8, the substrate 821 having the recess 820 is used, but the recess may be formed using a film different from the substrate over a flat substrate.

  The concave portion 820 has a curved surface, and the center of curvature of the curved surface exists on the light emitting element 822 side.

  The light-emitting element 822 includes an electrode 823 formed over the substrate 821, an electroluminescent layer 824 formed over the electrode 823, and an electrode 825 formed over the electroluminescent layer 824 so as to overlap the electrode 823. . Note that one of the electrodes 823 and 825 is an anode and the other is a cathode. Although FIG. 8 shows an example in which the electrode 823 is an anode and the electrode 825 is a cathode, the electrode 823 may be a cathode and the electrode 825 may be an anode. By applying a forward bias voltage between the electrodes 823 and 825, a current is supplied to the electroluminescent layer 824, so that the electroluminescent layer 824 can emit light.

  In FIG. 8, a layer having a convex portion 826 (hereinafter referred to as a convex layer) 827 is formed so as to cover the light emitting element 822. The convex portion 826 is formed so as to overlap with the light emitting element 822. Note that the convex layer 827 may be formed of a single layer or a plurality of layers. In any case, the convex layer 827 has translucency.

  In the laser oscillator shown in FIG. 8, an optical resonator is formed by electrodes 823 and 825 included in the light-emitting element 822, similarly to the laser oscillator shown in FIG. Light emitted from the electroluminescent layer 824 is resonated by the electrodes 823 and 825, and is oscillated from the electrode 825 side as laser light.

  Note that the optical resonator formed by the electrodes 823 and 825 is an unstable resonator. Therefore, it is considered that the oscillated laser light is easier to obtain single-mode laser light than the stable resonator, and the directivity is enhanced. In this embodiment, since the laser light is refracted at the convex portion 826 included in the convex layer 827, the divergence angle can be suppressed and the directivity of the laser light can be further increased. In order to suppress the divergence angle, the focal length of the convex portion 826 may be optically designed in accordance with the divergence angle of the laser light applied to the convex portion 826.

  Note that in FIG. 8, the two electrodes of the light-emitting element are used as the reflective material, but the present invention is not limited to this structure. In addition to the light emitting element, two additional reflecting materials may be provided, or one of the electrodes of the light emitting element may be used as the reflecting material, and one additional reflecting material may be provided. Alternatively, a layer other than the light-emitting layer included in the electroluminescent layer, for example, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, or the like is used as a reflective material, and light generated in the light-emitting layer is reflected, and an optical resonator May be formed.

  This embodiment can be implemented in combination with Embodiments 1 to 3 as appropriate. Note that the laser oscillator of the present invention may be used as a display device. The display device provided with the laser oscillator includes a projector, an LCD (Liquid Crystal Display) using the laser oscillator as a backlight, and the like. In particular, in the case of an FS-LCD, the R, G, and B light emitting elements shown in the second embodiment may be used. As an example of an FS-LCD (Field Sequential LCD), a structure disclosed in US2003 / 0058210 may be used.

  In this example, an example of a method for manufacturing a convex portion will be described.

  First, as shown in FIG. 9A, a resin 1002 that can be melted by heating is formed over a substrate 1001 on which convex portions are to be formed later. The resin 1002 is patterned in an island shape. For the substrate 1001, glass, quartz, metal, bulk semiconductor, plastic, or the like can be used.

  Next, as shown in FIG. 9B, the resin 1002 patterned in an island shape is melted by heating so that a curved surface is formed at the end. A resin 1003 having a curved surface formed by melting is shown.

  Then, as shown in FIG. 9C, the substrate 1001 is dry-etched using the resin 1003 as a mask. In dry etching, an optimum etching gas is used in accordance with the material of the substrate 1001. For example, when glass is used as the substrate 1001, a fluorine-based or chlorine-based etching gas such as CF4, CHF3, or Cl2 can be used as an etching gas. By dry etching, the resin 1003 is also etched together as shown in FIG. Accordingly, finally, as illustrated in FIG. 9D, the convex portion 1004 can be formed on the substrate 1001 in accordance with the shape of the resin 1003 having a curved surface.

  Next, as shown in FIG. 9E, a reflective film 1005 capable of reflecting laser light is formed on the side of the substrate 1001 where the convex portions 1004 are formed. When the process shown in FIG. 9E is completed, a light emitting element is formed over the reflective film 1005.

  Note that although the reflective film 1005 functioning as a reflective material is formed in this embodiment, an electrode of a light-emitting element formed later may be used as the reflective material, or the substrate 1001 itself may be used as the reflective material. good.

  This embodiment can be implemented in combination with Embodiments 1 to 4 as appropriate.

  In this embodiment, one mode of an electronic device using the laser oscillator of the present invention will be described.

  FIG. 11A shows an external view of a laser pointer using the laser oscillator of the present invention. 1201 corresponds to the main body of the laser pointer, and 1202 corresponds to the package in which the laser oscillator is housed. A battery or the like for supplying power to the package 1202 is provided inside the main body 1201. Reference numeral 1203 corresponds to a switch for controlling the power supply to the package 1202.

  FIG. 11B is an enlarged view of the package 1202. The package 1202 is provided with a laser oscillator 1205 of the present invention in a housing 1204 for shielding unnecessary radiation of laser light. Part of the housing 1204 has a window 1207 having a light transmitting property for extracting laser light oscillated from the laser oscillator 1205. The laser oscillator 1205 can receive power from a battery provided inside the main body 1201 via the lead 1206.

  FIG. 11C shows an enlarged view of the laser oscillator 1205. The laser oscillator 1205 includes a substrate 1208 having a convex portion and a light emitting element 1209 formed so as to overlap the convex portion. The light-emitting element 1209 includes two electrodes 1210 and 1211 and an electroluminescent layer 1212 provided between the electrodes 1210 and 1211. The electrodes 1210 and 1211 are electrically connected to the lead 1206 by wires 1214. 1213 corresponds to a resin for sealing the electroluminescent layer 1212 and can prevent the electroluminescent layer 1212 from being deteriorated by the influence of water, oxygen, or the like.

  When a forward bias voltage is applied between the electrodes 1210 and 1211 through the lead 1206, a current is supplied to the electroluminescent layer 1212 to generate light. The light generated in the electroluminescent layer 1212 resonates between the electrodes 1210 and 1211, and laser light is oscillated from the electrode 1210 side. Since the optical resonator formed by the electrodes 1210 and 1211 is an unstable resonator, laser light close to a single mode can be obtained. In addition, since part of the substrate 1208 functions as an optical system, unlike a case where an optical system is separately provided, resistance to a physical impact of an electronic device can be increased.

  This embodiment can be implemented in combination with Embodiments 1 to 5 as appropriate.

  In this example, a structure of a light emitting element used in the laser oscillator of the present invention will be described.

  FIG. 12 illustrates one embodiment of an element structure of a light-emitting element used in the present invention. The light-emitting element shown in FIG. 12 has a structure in which two electroluminescent layers 1303 and 1304 are sandwiched between an anode 1301 and a cathode 1302. Further, the light-emitting element illustrated in FIG. 12 includes a charge generation layer 1305 which is a floating electrode which is not connected to an external circuit between two electroluminescent layers 1303 and 1304. The electroluminescent layer 1303 includes a hole injection layer 1306, a hole transport layer 1307, a light emitting layer 1308, an electron transport layer 1309, and an electron injection layer 1310, which are sequentially stacked from the anode 1301 side. The electroluminescent layer 1304 includes a hole injection layer 1315, a hole transport layer 1311, a light emitting layer 1312, an electron transport layer 1313, and an electron injection layer 1314 which are sequentially stacked from the charge generation layer 1305 side.

  Note that the light-emitting element used in the laser oscillator of the present invention only needs to include at least a light-emitting layer in each electroluminescent layer. Layers having functions other than light emission (a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer) can be appropriately combined. The materials described in Example 1 can be referred to for the materials that can be used for the respective layers. However, the material applicable to the present invention is not limited to the material described in Example 1.

  When a forward bias voltage is applied between the anode 1301 and the cathode 1302 in the light-emitting element shown in FIG. 12, electrons are injected into the electroluminescent layer 1303 and holes are injected into the electroluminescent layer 1304, respectively. At 1303 and 1304, carrier recombination occurs and light emission is obtained. With the above structure, when the distance between the anode 1301 and the cathode 1302 is constant, the energy of light emission obtained for the same current value is higher than when the electroluminescent layer is one. Therefore, the laser beam oscillation efficiency can be increased.

  The charge generation layer 1305 is formed using a material that can transmit light. For example, ITO, a mixture of V2O5 and an arylamine derivative, a mixture of MoO3 and an arylamine derivative, a mixture of V2O5 and F4TCNQ (tetrafluorotetrathiafulvalene) can be used.

  In the case where the anode 1301 and the cathode 1302 are used as reflecting materials, the material or the film thickness is selected so that the reflectance of one is as large as possible and the transmittance of the other is about 5 to 70%. In the case where a reflective material is separately formed, a material that transmits light in the anode 1301 or the cathode 1302 is selected. The interval between the reflectors is set to an integral multiple of half the wavelength λ to be resonated. And the laminated structure of a light emitting element is designed so that the light reflected in a reflecting material and the phase of the newly emitted light may correspond.

  This embodiment can be implemented in combination with Embodiments 1 to 6 as appropriate.

  In this embodiment, the structure of the laser oscillator of the present invention in the case where a reflecting material having a convex portion and a reflecting material having a flat surface are used will be described.

  FIG. 13 shows a positional relationship between a reflective material 1500 having a convex portion, a reflective material 1501 having a flat surface, and a light source 1502. The light source 1502 corresponds to a laser medium that generates stimulated emission light. Specifically, in the present invention, the light source 1502 corresponds to a layer that generates light, such as a light emitting layer, of the electroluminescent layer. O corresponds to the focal point of the convex portion of the reflective material 1500, and O 'corresponds to the center of curvature of the convex portion of the reflective material 1500. f corresponds to the focal length, r corresponds to the radius of curvature, and the focal length f corresponds to half the radius of curvature r. The convex portion of the reflective material 1500 has a center of curvature O ′ on the side opposite to the reflective material 1501.

  It is assumed that the stimulated emission light emitted from the light source 1502 resonates between the reflective materials 1500 and 1501 so that the laser light is oscillated from the reflective material 1501. When the focal length of the convex portion of the reflector 1500 is f, the divergence angle of the laser beam is θ, the beam diameter of the laser beam in the reflector 1501 is W, and the resonator length is L, the divergence angle θ, the focal length f, The relationship between the resonator lengths L is expressed by the following equation (2).

  By using the equation shown in Equation 2, the shape of the convex portion can be optically designed so as to improve the directivity of the laser beam.

Sectional drawing and top view of the laser oscillator of this invention. Sectional drawing of the laser oscillator of this invention. Sectional drawing of the laser oscillator of this invention. Sectional drawing of the laser oscillator of this invention. FIG. 5 shows a structure of a light-emitting element used in a laser oscillator of the present invention. 4A and 4B are a top view and a cross-sectional view in the manufacturing process of the laser oscillator of the present invention. The top view and sectional drawing of the laser oscillator of this invention. Sectional drawing of the laser oscillator of this invention. The figure which shows one Example of the production method of a convex part. The figure which shows one Example of the production method of a convex part. The figure which shows the structure of the laser pointer using the laser oscillator of this invention. FIG. 5 shows a structure of a light-emitting element used in a laser oscillator of the present invention. The figure which shows the relationship between the divergence angle (theta), the focal distance f, and the resonator length L. FIG.

Explanation of symbols

100 convex portion 101 substrate 102 light emitting element 103 electrode 104 electroluminescent layer 105 electrode

Claims (6)

A first electrode having a protrusion having a first curved surface, and the first electroluminescent layer formed on the electrode so as to overlap with the convex portion, Oite the electroluminescent layer on the convex portion A light-emitting element having a second electrode having a transmittance of 5 to 70%, which is selectively formed so as to overlap with a part of the region including the upper end portion of the first electrode and has a concave portion having a second curved surface. And
The center of curvature of the first curved surface is located on the opposite side of the second electrode;
The center of curvature of the second curved surface is located on the first electrode side;
The light generated in the electroluminescent layer is reflected and resonated between the first electrode and the second electrode, and the resonated light is transmitted through the second electrode and emitted .
When the radius of curvature of the first electrode is r1, the radius of curvature of the second electrode is r2, and the distance between the first electrode and the second electrode is L,
A method for manufacturing a light-emitting device that satisfies the conditions of r1 <0 and 0 <r2 <L,
A resin that can be melted by heating is formed on the substrate,
Patterning the resin into islands,
By melting the resin patterned in the island shape by heating, a resin having a curved surface at the end is formed,
Using the resin having a curved surface at the end as a mask, dry etching the substrate together with the resin having a curved surface at the end to form a substrate having a convex portion having a curved surface,
A method for manufacturing a light-emitting device, wherein the light-emitting element is formed over a substrate having a convex portion having a curved surface. A first electrode having a protrusion having a first curved surface, and the first electroluminescent layer formed on the electrode so as to overlap with the convex portion, Oite the electroluminescent layer on the convex portion A light-emitting element having a second electrode having a transmittance of 5 to 70%, which is selectively formed so as to overlap with a part of the region including the upper end portion of the first electrode and has a concave portion having a second curved surface. And
The center of curvature of the first curved surface is located on the opposite side of the second electrode;
The center of curvature of the second curved surface is located on the first electrode side;
The light generated in the electroluminescent layer is reflected and resonated between the first electrode and the second electrode, and the resonated light is transmitted through the second electrode and emitted .
When the radius of curvature of the first electrode is r1, the radius of curvature of the second electrode is r2, and the distance between the first electrode and the second electrode is L,
A method for manufacturing a light-emitting device that satisfies the conditions of r1 <0, r2> L + | r1 |
A resin that can be melted by heating is formed on the substrate,
Patterning the resin into islands,
By melting the resin patterned in the island shape by heating, a resin having a curved surface at the end is formed,
Using the resin having a curved surface at the end as a mask, dry etching the substrate together with the resin having a curved surface at the end to form a substrate having a convex portion having a curved surface,
A method for manufacturing a light-emitting device, wherein the light-emitting element is formed over a substrate having a convex portion having a curved surface. A reflector provided with a convex portion having a first curved surface;
A translucent first electrode formed on the reflecting material so as to overlap the convex portion, an electroluminescent layer formed on the first electrode so as to overlap the convex portion, and the electroluminescence It formed selectively so as to overlap a portion of the region including the upper end portion of Oite the convex portions on the layer, yet transmittance with a recess having a second curved second is 5% to 70% A light emitting element having an electrode,
The center of curvature of the reflector is located on the opposite side of the second electrode;
The center of curvature of the second curved surface is located on the reflector side;
The light generated in the electroluminescent layer is reflected and resonated between the reflector and the second electrode, and the resonated light is transmitted through the second electrode and emitted .
When the radius of curvature of the reflective material is r1, the radius of curvature of the second electrode is r2, and the distance between the reflective material and the second electrode is L,
A method for manufacturing a light-emitting device that satisfies the conditions of r1 <0 and 0 <r2 <L,
A resin that can be melted by heating is formed on the substrate,
Patterning the resin into islands,
By melting the resin patterned in the island shape by heating, a resin having a curved surface at the end is formed,
Using the resin having a curved surface at the end as a mask, dry etching the substrate together with the resin having a curved surface at the end to form a substrate having a convex portion having a curved surface,
It said reflective material is formed on a substrate having a convex portion having the curved surface,
A method for manufacturing a light-emitting device, wherein the light-emitting element is formed over the reflective material. A reflector provided with a convex portion having a first curved surface;
A translucent first electrode formed on the reflecting material so as to overlap the convex portion, an electroluminescent layer formed on the first electrode so as to overlap the convex portion, and the electroluminescence It formed selectively so as to overlap a portion of the region including the upper end portion of Oite the convex portions on the layer, yet transmittance with a recess having a second curved second is 5% to 70% A light emitting element having an electrode,
The center of curvature of the reflector is located on the opposite side of the second electrode;
The center of curvature of the second curved surface is located on the reflector side;
The light generated in the electroluminescent layer is reflected and resonated between the reflector and the second electrode, and the resonated light is transmitted through the second electrode and emitted .
When the radius of curvature of the reflective material is r1, the radius of curvature of the second electrode is r2, and the distance between the reflective material and the second electrode is L,
A method for manufacturing a light-emitting device that satisfies the conditions of r1 <0, r2> L + | r1 |
A resin that can be melted by heating is formed on the substrate,
Patterning the resin into islands,
By melting the resin patterned in the island shape by heating, a resin having a curved surface at the end is formed,
Using the resin having a curved surface at the end as a mask, dry etching the substrate together with the resin having a curved surface at the end to form a substrate having a convex portion having a curved surface,
It said reflective material is formed on a substrate having a convex portion having the curved surface,
A method for manufacturing a light-emitting device, wherein the light-emitting element is formed over the reflective material. A first electrode having a convex portion having a first curved surface; a first electroluminescent layer formed on the first electrode so as to overlap the convex portion; and on the first electroluminescent layer. a charge generating layer formed, a second electroluminescent layer formed on the charge generating layer, a portion of the region including the upper end portion of Oite the convex portion to the second electroluminescent layer A light-emitting element having a second electrode having a transmittance of 5 to 70%, which is selectively formed so as to overlap and has a concave portion having a second curved surface,
The center of curvature of the first curved surface is located on the opposite side of the second electrode;
The center of curvature of the second curved surface is located on the first electrode side;
The light generated in the electroluminescent layer is reflected and resonated between the first electrode and the second electrode, and the resonated light is transmitted through the second electrode and emitted .
When the radius of curvature of the first electrode is r1, the radius of curvature of the second electrode is r2, and the distance between the first electrode and the second electrode is L,
A method for manufacturing a light-emitting device that satisfies the conditions of r1 <0, 0 <r2 <L or r1 <0, r2> L + | r1 |
A resin that can be melted by heating is formed on the substrate,
Patterning the resin into islands,
By melting the resin patterned in the island shape by heating, a resin having a curved surface at the end is formed,
Using the resin having a curved surface at the end as a mask, dry etching the substrate together with the resin having a curved surface at the end to form a substrate having a convex portion having a curved surface,
A method for manufacturing a light-emitting device, wherein the light-emitting element is formed over a substrate having a convex portion having a curved surface. A reflector provided with a convex portion having a first curved surface;
A first electrode having translucency formed on the reflective material so as to overlap the convex portion, a first electroluminescent layer formed on the first electrode so as to overlap the convex portion, a charge generating layer formed on the first electroluminescent layer, a second electroluminescent layer formed on the charge generating layer, and the upper end portion of Oite the convex portion to the second electroluminescent layer A light emitting element having a second electrode having a transmittance of 5 to 70%, which is selectively formed so as to overlap a part of the region including the concave portion having the second curved surface,
The center of curvature of the reflector is located on the opposite side of the second electrode;
The center of curvature of the second curved surface is located on the reflector side;
The light generated in the electroluminescent layer is reflected and resonated between the reflector and the second electrode, and the resonated light is transmitted through the second electrode and emitted .
When the radius of curvature of the reflective material is r1, the radius of curvature of the second electrode is r2, and the distance between the reflective material and the second electrode is L,
A method for manufacturing a light-emitting device that satisfies the conditions of r1 <0, 0 <r2 <L or r1 <0, r2> L + | r1 |
A resin that can be melted by heating is formed on the substrate,
Patterning the resin into islands,
By melting the resin patterned in the island shape by heating, a resin having a curved surface at the end is formed,
Using the resin having a curved surface at the end as a mask, dry etching the substrate together with the resin having a curved surface at the end to form a substrate having a convex portion having a curved surface,
Forming the reflector on a substrate having a convex portion having the curved surface;
A method for manufacturing a light-emitting device, wherein the light-emitting element is formed over the reflective material.

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