JP2003007450A - Light emitting element, display device and lighting device - Google Patents

Abstract

[PROBLEMS] To improve the display quality and reliability of an organic EL element, a display device using the same, and a display device and a lighting device using the organic EL element, by lowering the luminous efficiency and improving the uneven brightness of a display area due to heat generation of the organic EL element. improves. SOLUTION: At least a first electrode, a light emitting region containing an organic material, and a second electrode are sequentially formed on a substrate, and an insulating heat radiation layer is provided between the substrate and the first electrode. A light-emitting element in which the heat dissipation layer has a thermal conductivity of 50 W / mK or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a light emitting region containing an organic material consisting of a hole transport layer, a light emitting layer and an electron injection layer between a pair of electrodes, and by injecting carriers from both electrodes into the light emitting layer. The present invention relates to an organic electroluminescence device (hereinafter, referred to as an organic EL device) that causes a light emitting layer to emit light.

[0002]

2. Description of the Related Art A flat panel display using an organic EL device and a flat panel light source have been actively researched and developed as next-generation display materials.

In an organic EL element, for example, as shown in FIG. 12, a transparent electrode 12 using a transparent conductive material (ITO, SnO ₂ , InO ₃ , ZnO) forming an anode is formed on a glass substrate 10. On the transparent electrode 12, a light emitting region 18 (hole transport layer 14, which contains an organic material containing an organic material,
On the light emitting layer 16, the electron transporting layer 17) and the light emitting region 18, a metal electrode 50 made of MgAg, Ca, Al, MgIn or the like which constitutes a cathode is formed. Then, the holes injected from the transparent electrode 12 into the light emitting layer 16 and the metal electrode 50.
The electrons injected into the light emitting layer from the light emitting layer 16 recombine in the light emitting layer 16 to emit light. As shown in FIG. 12, the light emitted from the light emitting layer 16 passes through the transparent electrode and the glass substrate 1
Go out through 0. Further, the light that has traveled to the opaque metal electrode 50 side is reflected by the transparent electrode 50, travels to the glass substrate side, passes through the glass substrate, and exits to the outside. However, when the emitted light generated in such an EL element is emitted to the outside through the glass substrate 10, the emission rate is about 20%, and the remaining 80% is the emission layer 18 and the glass substrate 10. Waves are guided to be absorbed by the metal surface or emitted from the edge of the substrate.

An EL proposed in order to efficiently take out the light emission generated in the device to the outside of the device to improve the light emission efficiency.
The structure of the element is shown in FIG.

As shown in FIG. 13, a transparent conductive material (ITO, SnO ₂ , In) forming an electrode is formed on a glass substrate 10.
O ₃ , ZnO, etc.) or MgAg, Ca, Al, M
An electrode 12 made of a metal material such as gIn is formed, and a light emitting region 1 containing an organic material is formed on the electrode 12.
8 (hole transport layer 14, light emitting layer 16, electron transport layer 17),
A transparent electrode 51 is formed on the light emitting region 18. The transparent electrode 60 is not made of an opaque metal material as shown in FIG. 12, but is made of a transparent conductive film material made of ITO, SnO ₂ , InO ₃ , ZnO, or a complex of these oxides.

By using a transparent conductive film material for the transparent electrode 51, the light emitting region 1 is formed from the side of the cathode electrode which is the upper electrode of the device.
It is possible to take out the light emission generated in 8. FIG.
As shown in, the light emitted from the light emitting layer 16 passes through the transparent cathode electrode 51 and goes out. When the electrode 12 is made of an opaque metal material, the light that has traveled to the anode electrode 12 side is reflected by the anode electrode 12, travels to the transparent electrode 60 side, and passes through the transparent electrode 60 to the outside. When the electrode is made of a transparent conductive film material, for example, by combining it with a reflective layer (scattering layer) (not shown) on glass, the light emitting layer 1
The light emitted at 6 and traveling to the anode electrode 12 side is reflected by the anode electrode 12, travels to the transparent electrode 1351 side, passes through the transparent electrode 60, and exits to the outside.

Since the emitted light generated in such an organic EL element is not emitted to the outside through the glass substrate 10, the emission rate to the outside is increased as compared with the configuration of FIG.

[0008]

The organic EL element as shown in FIGS. 12 and 13 has a low heat resistant temperature because the light emitting layer contains an organic material.

Therefore, there is a problem that the heat generation of the organic EL element (including the heat generation of the driving element (not shown) on the substrate and the heat generation of the electrodes) accelerates the deterioration of the light emitting region and lowers the light emitting efficiency.

Further, a temperature distribution is generated depending on the light emitting region,
For example, in the case of a display using an organic EL element, there is a problem that unevenness in brightness occurs in the display area and display quality deteriorates.

The present invention has been made to solve the above-mentioned problems, and the heat generated from the organic EL element is radiated or evenly dispersed to reduce the luminous efficiency.
It is also an object of the present invention to reduce unevenness in brightness and to improve the display quality of an organic EL element, a display device using the same, and a lighting device.

[0012]

In a first light emitting device of the present invention, at least a first electrode, a light emitting region containing an organic material, and a second electrode are sequentially formed on a substrate, and the substrate and the first An insulating heat dissipation layer is provided between the electrodes, and the heat conductivity of the heat dissipation layer is 50 W / mK or more.

Preferably, the second electrode is transparent or semi-transparent, and the light is extracted from the second electrode side.

Preferably, a scattering layer and an insulating heat dissipation layer are sequentially formed on the substrate between the substrate and the first electrode, and the surface of the scattering layer is flattened by the heat dissipation layer. Characterize.

Preferably, the thickness of the heat dissipation layer is 15
It is characterized in that it is not less than nm.

Preferably, the heat dissipation layer also serves as a reflection layer.

Further, preferably, the heat dissipation layer is a multi-layer film.

In the second light emitting device of the present invention, at least a first electrode, a light emitting region containing an organic material, and a second electrode are sequentially formed on a substrate, and the substrate and the second electrode are formed on the substrate. It has an insulating heat dissipation layer, and the heat dissipation rate of the heat dissipation layer is 50.
It is W / mK or more.

Preferably, the heat dissipation layer of the first or second light emitting element is characterized by containing a compound containing at least aluminum, magnesium, silicon and carbon.

Further, it is preferable that the heat dissipation layer of the first or second light emitting element contains at least aluminum nitride, diamond-like carbon, magnesium oxide, or silicon carbide.

The display device of the present invention is a display device in which a drive circuit for driving the light emitting element is added to the above light emitting element.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) Embodiment 1 of the present invention will be described below. 1 is a sectional view showing a first embodiment of a light emitting device according to the present invention. In FIG. 1, 101
Is a substrate, 102 is a reflective electrode, 103 is a light emitting layer, 104 is a transparent electrode, 105 is a laminated film, and 106 is a light extraction surface.

The substrate 1 may be any one capable of supporting the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

The reflective electrode 102 has only to have a high reflectance and a function of efficiently emitting light from the light emitting layer, and it is preferable to use a metal film of Al or an Al compound, silver or a silver compound. Furthermore, as a silver compound, silver
It is preferable to use an alloy of palladium / copper (AgPdCu) or an alloy of silver / gold / copper (AgAuCu). Further, in the case of a so-called current injection type organic EL element using an organic compound as a light emitting layer, the reflective electrode is usually a cathode,
A material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As a method of forming the reflective electrode 102, a method such as sputtering, electron beam vapor deposition, resistance heating vapor deposition or the like may be used.

For the light emitting layer 103, for example, in the case of an organic EL element, an organic light emitting material such as Alq ₃ is used. Preferably, similar to the conventional structure, the light emitting layer 103 has a multilayer structure, that is, a hole transporting layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TPD.
A three-layer structure in which a hole-transporting layer using the above or the like, a light-emitting layer using perylene or the like, an electron-transporting layer using oxadiazole or the like is stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injecting electrode side such as ITO is used as the hole transporting layer, and the electron injecting electrode side such as AlLi and MgAg is used as the electron transporting layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 104, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer is deteriorated, so the transparent electrode 104 needs to be formed at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 104 is formed at a low temperature, the adhesion between the transparent electrode 104 and the base film is poor, and the transparent electrode 104 is easily peeled off. When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed by sputtering on the sputter-etched surface. More preferably.

An insulating film 105 made of an aluminum nitride film is formed on the substrate 101. Thermal conductivity is 170
It is about W / mK.

On the insulating film 105 made of aluminum nitride, a reflection electrode 102 made of Al patterned to have a predetermined shape is formed to a thickness of 100 nm.

As a method of forming the insulating film 105, 300
A 0.3 μm film is formed by a DC magnetron sputtering method using metallic Al and nitrogen gas under a temperature condition of ° C.

The aluminum nitride film also contains oxygen, has a thermal conductivity of about 170 W / mK, and is a transparent compound film.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

[0037]

[Table 1]

It can be seen that the aluminum nitride film has excellent thermal conductivity as compared with the SiO ₂ film which is a general insulating film. Therefore, the heat generated in the light emitting region and the electrode is radiated from the insulating film 105 and is evenly dispersed.

Table 2 shows the results of the durability test in this example.

[0040]

[Table 2]

The insulating film 105 is not limited to the above materials, and at least Al, Mg, Si, and C are selected.
It is preferably a compound film containing one or more. Also,
The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 105 is not limited to the above method, and sputtering, electron beam vapor deposition, resistance heating vapor deposition, CVD, coating type, vacuum arc method, electron shower method, anodizing method, etc. may be used. You can use it.

In the first embodiment, Al is formed on the substrate.
By forming the insulating film 105 made of N or the like having a high thermal conductivity and the reflective electrode 102 in this order, it is possible to prevent the deterioration of the light emitting region and the uneven brightness, resulting in a long life,
Further, it is possible to obtain a light emitting element, a display device, and a lighting device which are highly reliable and have good display quality.

(Second Embodiment) A second embodiment of the present invention will be described below. 2 is a sectional view showing a second embodiment of a light emitting device according to the present invention. In FIG. 2, 201
Is a substrate, 202 is a transparent electrode, 203 is a light emitting layer, 204 is a transparent electrode, 205 is an insulating film, and 206 is a light extraction surface.

The substrate 1 may be any one capable of supporting the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

For the light emitting layer 203, for example, in the case of an organic EL element, an organic light emitting material such as Alq ₃ is used. Preferably, similar to the conventional structure, the light emitting layer 103 has a multilayer structure, that is, a hole transporting layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TPD.
A three-layer structure in which a hole-transporting layer using the above or the like, a light-emitting layer using perylene or the like, an electron-transporting layer using oxadiazole or the like is stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injecting electrode side such as ITO is used as the hole transporting layer, and the electron injecting electrode side such as AlLi and MgAg is used as the electron transporting layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

It is sufficient that the reflective electrode 204 has a high reflectance and a function of efficiently emitting light from the light emitting layer, and it is preferable to use a metal film of Al or an Al compound, silver or a silver compound. Furthermore, as a silver compound, silver
It is preferable to use an alloy of palladium / copper (AgPdCu) or an alloy of silver / gold / copper (AgAuCu). Further, in the case of a so-called current injection type organic EL element using an organic compound as a light emitting layer, the reflective electrode is usually a cathode,
A material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As a method for forming the reflective electrode 204, a method such as sputtering, electron beam vapor deposition, resistance heating vapor deposition or the like may be used.

As the transparent electrode 202, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

An insulating film 205 made of an aluminum nitride film is formed on the substrate 201. Thermal conductivity is 175
It is about W / mK.

On the insulating film 205 made of aluminum nitride, a transparent electrode 202 made of ITO patterned in a predetermined shape is formed to a thickness of 100 nm.

As a method of forming the insulating film 205, 300
It is formed to a thickness of 0.5 μm by a DC magnetron sputtering method using metallic Al and nitrogen gas under the temperature condition of ℃.

The aluminum nitride film has a high reflectance and efficiently extracts the light emitted in the light emitting region.
It can be reflected to 6.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

It can be seen that the aluminum nitride film has excellent thermal conductivity as compared with the SiO ₂ film which is a general insulating film. Therefore, the heat generated in the light emitting region and the electrode is radiated from the insulating film formed on the transparent conductive film and is evenly dispersed.

Table 2 shows the results of the durability test in this example.

The insulating film 205 is not limited to the above materials, and at least Al, Mg, Si, and C are selected.
It is preferably a compound film containing one or more. Also,
The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film 205 is preferably 15 nm or more.

The method of forming the insulating film 205 is not limited to the above method, and sputtering, electron beam vapor deposition, resistance heating vapor deposition, CVD, coating type, vacuum arc method, electron shower method, anodic oxidation method, etc. may be used. You can use it.

In the second embodiment, the insulating film 205 made of AlN or the like and having a high thermal conductivity and the transparent electrode 202 are formed in this order on the substrate 202 to prevent deterioration of the light emitting region and uneven brightness. It is possible to provide a light-emitting element having a long life, high reliability, and good display quality,
A display device and a lighting device can be obtained.

(Embodiment 3) Embodiment 1 of the present invention will be described below. FIG. 3 is a sectional view showing a third embodiment of a light emitting device according to the present invention. In FIG. 3, 301
Is a substrate, 302 is a reflective electrode, 303 is a light emitting layer, 304 is a transparent electrode, 305 is a laminated film, and 306 is a light extraction surface.

The substrate 1 may be any one that can carry the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

The reflective electrode 302 has only to have a high reflectance and a function of efficiently emitting light from the light emitting layer, and it is preferable to use a metal film of Al or an Al compound, silver or a silver compound. Furthermore, as a silver compound, silver
It is preferable to use an alloy of palladium / copper (AgPdCu) or an alloy of silver / gold / copper (AgAuCu). Further, in the case of a so-called current injection type organic EL element using an organic compound as a light emitting layer, the reflective electrode is usually a cathode,
A material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As a method of forming the reflective electrode 302, a method such as sputtering, electron beam vapor deposition, resistance heating vapor deposition or the like may be used.

As the light emitting layer 103, for example, in the case of an organic EL element, an organic light emitting material such as Alq ₃ is used. Preferably, similar to the conventional structure, the light emitting layer 103 has a multilayer structure, that is, a hole transporting layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TPD.
A three-layer structure in which a hole-transporting layer using the above or the like, a light-emitting layer using perylene or the like, an electron-transporting layer using oxadiazole or the like is stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injection electrode side such as ITO is used as the hole transport layer, and the electron injection electrode side such as AlLi and MgAg is used as the electron transport layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 304, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer deteriorates. Therefore, it is necessary to form the transparent electrode 304 at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 304 is formed at a low temperature, the adhesion between the transparent electrode 304 and the base film is poor, and the transparent electrode 304 is easily peeled off. When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce the damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed on the surface that has been sputter-etched by sputtering. More preferably.

An insulating film 305 made of a diamond-like carbon film is formed on the substrate 301. The thermal conductivity is about 240 W / mK.

On the insulating film 305 made of diamond-like carbon, Al patterned into a predetermined shape is formed.
Is formed to a thickness of 100 nm.

As a method for forming the insulating film 305, a plasma CVD method is used to form the film to a thickness of 0.3 μm.

Table 1 shows the material of the insulating film, thermal conductivity and electric resistivity.

It can be seen that the diamond-like carbon film has excellent thermal conductivity as compared with the SiO ₂ film which is a general insulating film. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 305.

Table 2 shows the results of the durability test in this example.

The insulating film 305 is not limited to the above materials, and at least Al, Mg, Si, and C are selected.
It is preferably a compound film containing one or more. Also,
The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 305 is not limited to the above method.

In the third embodiment, the laminated film 305 having high thermal conductivity such as diamond-like carbon and the reflective electrode 302 are formed in this order on the substrate 301, thereby deteriorating the light emitting region and uneven brightness. Therefore, it is possible to obtain a light-emitting element, a display device, and a lighting device which have a long life, high reliability, and good display quality.

(Fourth Embodiment) The fourth embodiment of the present invention will be described below. Fourth Embodiment FIG. 4 is a sectional view showing a fourth embodiment of a light emitting device according to the present invention. In FIG. 4, 401
Is a substrate, 402 is a reflective electrode, 403 is a light emitting layer, 404 is a transparent electrode, 405 is a laminated film, and 406 is a light extraction surface.

The substrate 1 may be any one that can carry the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

It is sufficient that the reflective electrode 402 has a high reflectance and a function of efficiently emitting light from the light emitting layer, and it is preferable to use a metal film of Al or an Al compound, silver or a silver compound. Furthermore, as a silver compound, silver
It is preferable to use an alloy of palladium / copper (AgPdCu) or an alloy of silver / gold / copper (AgAuCu). Further, in the case of a so-called current injection type organic EL element using an organic compound as a light emitting layer, the reflective electrode is usually a cathode,
A material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As a method of forming the reflective electrode 402, a method such as sputtering, electron beam vapor deposition, resistance heating vapor deposition or the like may be used.

For the light emitting layer 403, for example, in the case of an organic EL element, an organic light emitting material such as Alq ₃ is used. Preferably, similar to the conventional structure, the light emitting layer 403 has a multilayer structure, that is, a hole transport layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TPD.
A three-layer structure in which a hole-transporting layer using the above or the like, a light-emitting layer using perylene or the like, an electron-transporting layer using oxadiazole or the like is stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injection electrode side such as ITO is used as the hole transport layer, and the electron injection electrode side such as AlLi and MgAg is used as the electron transport layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 404, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer is deteriorated. Therefore, it is necessary to form the transparent electrode 404 at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 404 is formed at a low temperature, the adhesion between the transparent electrode 404 and the base film is poor, and the transparent electrode 404 easily peels off. When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed by sputtering on the sputter-etched surface. More preferably.

An insulating film 305 made of a MgO film is formed on the substrate 401. The thermal conductivity is about 120 W / mK.

On the insulating film 405 made of MgO, the reflective electrode 40 made of Al patterned into a predetermined shape is formed.
2 is formed to 100 nm.

As a method of forming the insulating film 405, a 0.2 μm film is formed by using a sputtering method.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

The MgO film is SiO, which is a general insulating film.
It can be seen that the film has excellent thermal conductivity as compared with the _two films. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 405.

Table 2 shows the results of the durability test in this example.

The insulating film 405 is not limited to the above materials, and at least Al, Mg, Si, and C are selected.
It is preferably a compound film containing one or more. Also,
The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 405 is not limited to the above method.

In the fourth embodiment, the insulating film 405 having a high thermal conductivity made of MgO or the like and the reflective electrode 402 are formed in this order on the substrate 401 to prevent deterioration of the light emitting region and uneven brightness. It is possible to provide a light-emitting element having a long life, high reliability, and good display quality,
A display device and a lighting device can be obtained.

(Fifth Embodiment) The first embodiment of the present invention will be described below. FIG. 5 is a sectional view showing a fifth embodiment of a light emitting device according to the present invention. In FIG. 5, 501
Is a substrate, 502 is a reflective electrode, 503 is a light emitting layer, 504 is a transparent electrode, 505 is a laminated film, and 506 is a light extraction surface.

The substrate 1 may be any one capable of supporting the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

The reflective electrode 502 has only to have a high reflectance and a function of efficiently emitting light from the light emitting layer, and it is preferable to use a metal film of Al or an Al compound, silver or a silver compound. Furthermore, as a silver compound, silver
It is preferable to use an alloy of palladium / copper (AgPdCu) or an alloy of silver / gold / copper (AgAuCu). Further, in the case of a so-called current injection type organic EL element using an organic compound as a light emitting layer, the reflective electrode is usually a cathode,
A material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As the method of forming the reflective electrode 502, sputtering, electron beam evaporation, resistance heating evaporation, or the like may be used.

As the light emitting layer 503, for example, in the case of an organic EL element, an organic light emitting material such as Alq ₃ is used. Preferably, as in the conventional structure, the light emitting layer 503 has a multilayer structure, that is, a hole transport layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TPD.
A three-layer structure in which a hole-transporting layer using the above or the like, a light-emitting layer using perylene or the like, an electron-transporting layer using oxadiazole or the like is stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injection electrode side such as ITO is used as the hole transport layer, and the electron injection electrode side such as AlLi and MgAg is used as the electron transport layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 504, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer deteriorates. Therefore, it is necessary to form the transparent electrode 504 at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 504 is formed at a low temperature, the adhesion between the transparent electrode 504 and the base film is poor, and the transparent electrode 504 is likely to peel off. When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce the damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed by sputtering on the surface. More preferably.

An insulating film 505 made of a SiC film is formed on the substrate 501. The thermal conductivity is about 160 W / mK.

On the insulating film 505 made of SiC, the reflective electrode 50 made of Al patterned into a predetermined shape is formed.
2 is formed to 100 nm.

As a method of forming the insulating film 505, 300 nm is formed by using the plasma CVD method.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

The SiC film is SiO, which is a general insulating film.
It can be seen that the film has excellent thermal conductivity as compared with the _two films. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 505.

Table 2 shows the results of the durability test in this example.

The insulating film 505 is not limited to the above materials, and at least Al, Mg, Si, and C are selected.
It is preferably a compound film containing one or more. Also,
The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 505 is not limited to the above method.

In the fifth embodiment, the laminated film 505 having a high thermal conductivity made of SiC or the like and the reflective electrode 502 are formed in this order on the substrate 501 to prevent deterioration of the light emitting region and uneven brightness. It is possible to provide a light-emitting element having a long life, high reliability, and good display quality,
A display device and a lighting device can be obtained.

(Sixth Embodiment) Next, a sixth embodiment of the present invention will be described with reference to FIG. 6 is a sectional view showing a sixth embodiment according to the present invention. In FIG. 6, 610 is a scattering layer, 605 is an insulating layer (planarizing layer), and 608 is a transparent electrode. Since the scattering layer 610 does not function as an electrode in this case, it is sufficient that the scattering layer 610 has a high reflectance and isotropically scatters the light generated in the light emitting layer 603. As the scattering layer 610, it is preferable to use a metal film of Al, an Al compound, silver, a silver compound, or the like. Further, as the silver compound, AgPdCu or AgAu is used.
It is preferable to use Cu. The flattening layer 607 may be a transparent insulating film, and for example, an inorganic material such as SiO ₂ or a polymer material such as polymethylmethacrylate (PMMA) can be used. Inorganic materials such as SiO ₂
The film may be formed by a sputtering method, an electron beam vapor deposition method, a CVD method, or the like. The polymer film such as PMMA may be formed by a coating method such as a spin coating method or a casting method. The transparent electrode 608 is similar to the transparent electrode 604 in that
An oxide transparent electrode such as TO or ZnO may be used. By introducing the insulating layer 605 that also serves as the flattening layer as in this embodiment, it is possible to prevent the transparent electrode 602 and the transparent electrode 604 from being short-circuited due to the unevenness of the scattering layer 610 in the configuration of FIG. 6, for example. be able to.

The insulating layer (flattening layer) 605 is a mixture of epoxy resin and high thermal conductive filler MgO, and is formed to a thickness of 3 μm by spin coating. The thermal conductivity is about 50 W / mK.

A transparent electrode 608 made of ITO patterned in a predetermined shape is formed on the insulating film 605.
It is formed to have a thickness of 00 nm.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

High heat conductive filler M is added to epoxy resin.
It can be seen that the insulating layer 605 mixed with gO has characteristics that the thermal conductivity is superior to that of the SiO ₂ film which is a general insulating film. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 605.

The insulating layer 605 is not limited to the above materials, and may be an inorganic film, an organic film, or a mixture of inorganic and organic. For example, the organic material may be a conductive filler such as MgO or Si. It is also possible to increase the thermal conductivity by mixing.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 605 is not limited to the above method.

Table 1 shows the results of the durability test in this example.

According to the present invention, by forming the insulating layer 605, it is possible to prevent the deterioration of the light emitting region and the uneven brightness, and the light emitting element and the display device having high reliability and good display quality are provided. And a lighting device can be obtained.

(Seventh Embodiment) Next, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 7 is a sectional view showing a seventh embodiment according to the present invention. In FIG. 7, 710 is a scattering layer, 705 is a multilayer film (705b,
705a) is an insulating layer and 708 is a transparent electrode.
Since the scattering layer 710 does not function as an electrode in this case,
It suffices that the reflectance is high and the light generated in the light emitting layer 703 can be scattered isotropically. As the scattering layer 710, it is preferable to use a metal film of Al, an Al compound, silver, a silver compound, or the like. Furthermore, as a silver compound, AgPdC
It is preferable to use u or AgAuCu. The insulating film 705 is a multi-layer film including two insulating films. The insulating film 705a also serves as a planarization layer. The insulating film 705a which also serves as the flattening layer may be a transparent insulating film, and for example, an inorganic material such as SiO ₂ or a polymer material such as polymethylmethacrylate (PMMA) can be used.
The inorganic material such as SiO ₂ may be formed by a method such as a sputtering method, an electron beam vapor deposition method, a CVD method or the like. PM
The polymer film such as MA may be formed by a coating method such as a spin coating method or a casting method. The transparent electrode 708 is
Similar to the transparent electrode 704, an oxide transparent electrode such as ITO or ZnO may be used. By introducing the insulating layer 705a that also serves as the flattening layer as in this embodiment, it is possible to prevent the transparent electrode 702 and the transparent electrode 704 from being short-circuited due to the unevenness of the scattering layer 710 in the configuration of FIG. 7, for example. be able to.

The insulating film 705a which also serves as a flattening layer is made of epoxy resin mixed with high thermal conductive filler Si and is formed to a thickness of 3 μm by spin coating.
The thermal conductivity is about 85 W / mK.

On the insulating film 705a, an insulating film 705b made of aluminum nitride is formed by 2000A. The insulating film 205b is formed by DC magnetron sputtering using metal Al and nitrogen gas under the temperature condition of 300 ° C.

The thermal conductivity of the insulating film 705b is 120 W / m.
It is about K. A transparent electrode 708 made of ITO patterned in a predetermined shape is formed on the insulating film 705b.
It is formed to 0 nm.

Table 1 shows the insulating film material, thermal conductivity, and electrical resistivity.

The flattening layer 705a in which a high thermal conductive filler is mixed with Si in an epoxy resin and the insulating film 705 made of an insulating film 705b made of aluminum nitride are compared with a SiO ₂ film which is a general insulating film. It can be seen that the film has excellent thermal conductivity. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 605.

The insulating layer 705 is not limited to the above materials, and may be an inorganic film, an organic film, or a mixture of inorganic and organic. For example, the organic material may be a conductive filler such as MgO or Si. It is also possible to increase the thermal conductivity by mixing.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 705 is not limited to the above method.

Table 1 shows the results of the durability test in this example.

According to the present invention, by forming the insulating layer 605, it is possible to prevent the deterioration of the light emitting region and the uneven brightness, and the light emitting element and the display device having high reliability and good display quality are provided. And a lighting device can be obtained.

(Embodiment 8) Embodiment 8 of the present invention will be described below. 8 is a sectional view showing Embodiment 8 of the light emitting device according to the present invention. In FIG. 8, 801
Is a substrate, 802 is a reflective electrode, 803 is a light emitting layer, 804 is a transparent electrode, 805 is a laminated film, and 806 is a light extraction surface.

The substrate 1 may be any one that can carry the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

The reflecting electrode 802 has only to have a high reflectance and a function of efficiently emitting light from the light emitting layer, and it is preferable to use a metal film of Al or an Al compound, silver or a silver compound. Furthermore, as a silver compound, silver
It is preferable to use an alloy of palladium / copper (AgPdCu) or an alloy of silver / gold / copper (AgAuCu). Further, in the case of a so-called current injection type organic EL element using an organic compound as a light emitting layer, the reflective electrode is usually a cathode,
A material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As the method of forming the reflective electrode 802, sputtering, electron beam evaporation, resistance heating evaporation, or the like may be used.

For the light emitting layer 803, for example, in the case of an organic EL element, an organic light emitting material such as Alq ₃ is used. Preferably, as in the conventional structure, the light emitting layer 803 has a multilayer structure, that is, a hole transport layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TPD.
A three-layer structure in which a hole-transporting layer using the above or the like, a light-emitting layer using perylene or the like, an electron-transporting layer using oxadiazole or the like is stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injection electrode side such as ITO is used as the hole transport layer, and the electron injection electrode side such as AlLi and MgAg is used as the electron transport layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 804, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer deteriorates. Therefore, it is necessary to form the transparent electrode 804 at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 804 is formed at a low temperature, the adhesion between the transparent electrode 804 and the base film is poor, and the transparent electrode 804 is easily peeled off. When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce the damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed by sputtering on the sputter-etched surface. More preferably.

An insulating film 805 made of an aluminum nitride film is formed on the transparent electrode 804. Thermal conductivity is 1
It is about 70 W / mK.

On the insulating film 805 made of aluminum nitride, a reflective electrode 802 made of Al patterned to have a predetermined shape is formed with a thickness of 100 nm.

As a method of forming the insulating film 805, 300
A 0.3 μm film is formed by a DC magnetron sputtering method using metallic Al and nitrogen gas under a temperature condition of ° C.

The aluminum nitride film also contains oxygen, has a thermal conductivity of about 170 W / mK, and is a transparent compound film.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

It can be seen that the aluminum nitride film has excellent thermal conductivity as compared with the SiO ₂ film which is a general insulating film. Therefore, the heat generated in the light emitting region and the electrode is radiated from the insulating film 805 and is evenly dispersed.

Table 2 shows the results of the durability test in this example.

The insulating film 805 is not limited to the above materials, and at least Al, Mg, Si, and C are selected.
It is preferably a compound film containing one or more. Also,
The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 805 is not limited to the above method, and sputtering, electron beam evaporation, resistance heating evaporation, CVD, coating type, vacuum arc method, electron shower method, anodic oxidation method, etc. may be used. You can use it.

In the eighth embodiment, Al is formed on the substrate.
By forming the insulating film 805 having a high thermal conductivity made of N or the like and the reflective electrode 802 in this order, it is possible to prevent deterioration of the light emitting region and uneven brightness, which leads to a long life.
Further, it is possible to obtain a light emitting element, a display device, and a lighting device which are highly reliable and have good display quality.

(Ninth Embodiment) The ninth embodiment of the present invention will be described below. 9 is a sectional view showing a third embodiment of a light emitting device according to the present invention. In FIG. 9, 901
Is a substrate, 902 is a reflective electrode, 903 is a light emitting layer, 904 is a transparent electrode, 905 is a laminated film, and 906 is a light extraction surface.

The substrate 1 may be any one capable of supporting the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

The reflective electrode 902 has only to have a high reflectance and a function of efficiently emitting light from the light emitting layer, and it is preferable to use a metal film of Al or an Al compound, silver or a silver compound. Furthermore, as a silver compound, silver
It is preferable to use an alloy of palladium / copper (AgPdCu) or an alloy of silver / gold / copper (AgAuCu). Further, in the case of a so-called current injection type organic EL element using an organic compound as a light emitting layer, the reflective electrode is usually a cathode,
A material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As a method of forming the reflective electrode 902, a method such as sputtering, electron beam vapor deposition, resistance heating vapor deposition or the like may be used.

For the light emitting layer 903, for example, in the case of an organic EL element, an organic light emitting material such as Alq ₃ is used. Preferably, similar to the conventional structure, the light emitting layer 103 has a multilayer structure, that is, a hole transporting layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TPD.
A three-layer structure in which a hole-transporting layer using the above or the like, a light-emitting layer using perylene or the like, an electron-transporting layer using oxadiazole or the like is stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injection electrode side such as ITO is used as the hole transport layer, and the electron injection electrode side such as AlLi and MgAg is used as the electron transport layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 904, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer deteriorates. Therefore, it is necessary to form the transparent electrode 904 at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 904 is formed at a low temperature, the adhesion between the transparent electrode 304 and the base film is poor, and the transparent electrode 904 is likely to peel off. When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce the damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed by sputtering on the sputter-etched surface. More preferably.

An insulating film 305 made of a diamond-like carbon film is formed on the transparent electrode 904. The thermal conductivity is about 240 W / mK.

On the insulating film 905 made of diamond-like carbon, Al patterned into a predetermined shape is formed.
Is formed to a thickness of 100 nm.
As a method of forming the insulating film 905, a plasma CVD method is used to form it to a thickness of 0.3 μm.

Table 1 shows the insulating film material, thermal conductivity, and electrical resistivity.

It can be seen that the diamond-like carbon film has excellent thermal conductivity as compared with the SiO ₂ film which is a general insulating film. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 905.

Table 2 shows the results of the durability test in this example.

The insulating film 905 is not limited to the above materials, and at least Al, Mg, Si, and C are selected.
It is preferably a compound film containing one or more. Also,
The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 905 is not limited to the above method.

In the ninth embodiment, the laminated film 905 having high thermal conductivity such as diamond-like carbon and the reflective electrode 902 are formed in this order on the substrate 901, thereby deteriorating the light emitting region and uneven brightness. Therefore, it is possible to obtain a light-emitting element, a display device, and a lighting device which have a long life, high reliability, and good display quality.

(Tenth Embodiment) The tenth embodiment of the present invention will be described below. 10 is a sectional view showing a tenth embodiment of a light emitting device according to the present invention. In FIG. 10, 1001 is a substrate, 1012 is a reflective electrode, 1013 is a light emitting layer, 1004 is a transparent electrode, 1005 is a laminated film, 10
Reference numeral 06 is a light extraction surface.

The substrate 1 may be any one that can carry the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

The reflective electrode 1002 may have a high reflectance and a function of causing the light emitting layer to emit light efficiently.
Alternatively, it is preferable to use a metal film such as an Al compound, silver, or a silver compound. Further, as the silver compound, an alloy of silver, palladium, copper (AgPdCu) or silver
It is preferable to use an alloy of gold and copper (AgAuCu).
Further, in the case of a so-called current injection type organic EL element in which an organic compound is used as a light emitting layer, the reflective electrode usually serves as a cathode, and a material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As a method of forming the reflective electrode 1002, a method such as sputtering, electron beam vapor deposition, resistance heating vapor deposition or the like may be used.

The light emitting layer 1003 is, for example, an organic EL.
In the case of a device, an organic light emitting material such as Alq ₃ is used. Preferably, similar to the conventional structure, the light emitting layer 403 has a multilayer structure, that is, a hole transporting layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TP.
A hole transporting layer using D or the like, a light emitting layer using perylene or the like,
A three-layer structure in which electron transport layers using oxadiazole or the like are stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injection electrode side such as ITO is used as the hole transport layer, and the electron injection electrode side such as AlLi and MgAg is used as the electron transport layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 1004, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer deteriorates. Therefore, it is necessary to form the transparent electrode 1004 at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 1004 is formed at a low temperature, the adhesion between the transparent electrode 1004 and the base film is poor, and the transparent electrode 404 easily peels off. When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce the damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed by sputtering on the sputter-etched surface. More preferably.

An insulating film 1005 made of a MgO film is formed on the transparent electrode 1004. Thermal conductivity is 120W
/ MK.

On the insulating film 1005 made of MgO, the reflective electrode 1 made of Al patterned into a predetermined shape is formed.
002 has a thickness of 100 nm.

As a method of forming the insulating film 1005, a sputtering method is used to form the insulating film 1005 to a thickness of 0.2 μm.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

The MgO film is SiO, which is a general insulating film.
It can be seen that the film has excellent thermal conductivity as compared with the _two films. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 1005.

Table 2 shows the results of the durability test in this example.

The insulating film 1005 is not limited to the above materials, and is preferably a compound film containing at least one of Al, Mg, Si and C. The thermal conductivity of the compound film may be 50 W / mK or more.

The film thickness of the insulating film is preferably 15 nm or more.

The method of forming the insulating film 1005 is not limited to the above method.

In the tenth embodiment, the substrate 100
1. An insulating film 100 made of MgO or the like having a high thermal conductivity
5 and the reflective electrode 1002 are formed in this order, deterioration of the light emitting region and uneven brightness can be prevented, and the light emitting element and the display device have a long life, high reliability, and good display quality. And a lighting device can be obtained.

(Eleventh Embodiment) The eleventh embodiment of the present invention will be described below. 11 is a sectional view showing Embodiment 11 of a light emitting device according to the present invention. In FIG. 11, 1101 is a substrate, 1102 is a reflective electrode, 1103 is a light emitting layer, 1104 is a transparent electrode, 1105 is a laminated film, 11
Reference numeral 06 is a light extraction surface.

The substrate 1 may be any one capable of supporting the light emitting device of the present invention, such as glass or polycarbonate,
A resin film such as polymethylmethacrylate or polyethylene terephthalate, a silicon substrate, or the like can be used.

The reflection electrode 1102 has only to have a high reflectance and a function of efficiently emitting light from the light emitting layer.
Alternatively, it is preferable to use a metal film such as an Al compound, silver, or a silver compound. Further, as the silver compound, an alloy of silver, palladium, copper (AgPdCu) or silver
It is preferable to use an alloy of gold and copper (AgAuCu).
Further, in the case of a so-called current injection type organic EL element in which an organic compound is used as a light emitting layer, the reflective electrode usually serves as a cathode, and a material having a high electron injection efficiency, that is, a material having a low work function is often used. As the cathode of the organic EL element, for example, a metal having a low work function but a high reactivity (Li, Mg, etc.) such as an Al-Li alloy, a Mg-Ag alloy, etc. and a metal having a low reactivity and a stable property (Al, Ag, etc.) The alloy of and may be used. Alternatively, a laminated electrode of a metal having a low work function such as Li / Al or LiF / Al or a compound thereof and a metal having a high work function, a laminated electrode of a metal such as ITO / Al / ITO and a transparent conductive film, and the like can be used.

As a method of forming the reflective electrode 1102, a method such as sputtering, electron beam vapor deposition, resistance heating vapor deposition or the like may be used.

The light emitting layer 1103 is, for example, an organic EL.
In the case of a device, an organic light emitting material such as Alq ₃ is used. Preferably, as in the conventional structure, the light emitting layer 503 has a multilayer structure, that is, a hole transporting layer using TPD or the like, a two-layer structure in which an electron transporting light emitting layer using Alq ₃ or the like is laminated, or TP.
A hole transporting layer using D or the like, a light emitting layer using perylene or the like,
A three-layer structure in which electron transport layers using oxadiazole or the like are stacked, or a multilayer structure with more than three layers may be used.

In this case, the hole injection electrode side such as ITO is used as the hole transport layer, and the electron injection electrode side such as AlLi and MgAg is used as the electron transport layer. In the case of an organic EL element, the light emitting layer is mainly formed by the resistance heating vapor deposition method, but an electron beam vapor deposition method, a sputtering method or the like may be used.

As the transparent electrode 1104, an oxide transparent electrode such as ITO or tin oxide may be used. The transparent electrode is formed by a sputtering method, a resistance heating vapor deposition method, an electron beam vapor deposition method, an ion plating method, or the like.

In the case of an organic EL element, if the substrate to which the organic light emitting layer is attached is heated to a high temperature, the organic layer is deteriorated, so the transparent electrode 1104 needs to be formed at a low temperature. Furthermore, when ITO or the like is formed as a transparent electrode on the organic light emitting layer by a sputtering method, an electron beam vapor deposition method, or the like,
In order to reduce damage to the organic layer, it is preferable to form the buffer layer on the organic layer and then form the transparent electrode.
For the buffer layer, a thermally stable organic compound such as copper phthalocyanine may be used. Since the transparent electrode 1104 is formed at a low temperature, the adhesion between the transparent electrode 1104 and the base film is poor, and the transparent electrode 1104 is easily peeled off.
When forming the transparent electrode by the sputtering method, it is preferable to form the transparent electrode by sputtering on the surface subjected to the sputter etching process in order to improve the adhesion between the transparent electrode and the base film.

In this case, in order to reduce the damage to the organic light emitting layer, the surface of the buffer layer formed on the organic layer is sputter-etched, and the transparent electrode is formed by sputtering on the surface. More preferably.

An insulating film 1105 made of a SiC film is formed on the transparent electrode 1101. Thermal conductivity is 160W
/ MK.

On the insulating film 1105 made of SiC, the reflective electrode 1 made of Al patterned in a predetermined shape is formed.
102 has a thickness of 100 nm.

The insulating film 1105 is formed to a thickness of 300 nm by using the plasma CVD method.

Table 1 shows the material of the insulating film, the thermal conductivity and the electrical resistivity.

The SiC film is SiO, which is a general insulating film.
It can be seen that the film has excellent thermal conductivity as compared with the _two films. Therefore, the heat generated in the light emitting region and the electrode is dispersed and radiated from the insulating film 1105.

Table 2 shows the results of the durability test in this example.

The insulating film 1105 is not limited to the above materials, and is preferably a compound film containing at least one of Al, Mg, Si and C. The thermal conductivity of the compound film may be 50 W / mK or more.

The thickness of the insulating film is preferably 15 nm or more.

The method for forming the insulating film 1105 is not limited to the above method.

In the eleventh embodiment, the substrate 110
An insulating film 110 made of SiC or the like and having a high thermal conductivity
5 and the reflective electrode 1102 are formed in this order, deterioration of the light emitting region and uneven brightness can be prevented, and a long-life and highly reliable light emitting device and display device with good display quality are provided. Can be obtained.

FIG. 12 shows the luminance half time when the light emitting elements described in Embodiments 1 to 11 having various heat dissipation layers are driven with a constant current.

[0218]

With the above structure, when the light emitting element is driven,
Heat generated from the light emitting element itself or a driving element that drives the light emitting element can be efficiently dissipated, and the life of the element can be improved. In the case of an element having a scattering layer, it can also serve as flattening of the scattering layer.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a light emitting device according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the light emitting device according to the present invention.

FIG. 3 is a sectional view showing a third embodiment of the light emitting device according to the present invention.

FIG. 4 is a sectional view showing a fourth embodiment according to the present invention.

FIG. 5 is a sectional view showing a fifth embodiment according to the present invention.

FIG. 6 is a sectional view showing a sixth embodiment according to the present invention.

FIG. 7 is a sectional view showing a seventh embodiment according to the present invention.

FIG. 8 is a sectional view showing an eighth embodiment according to the present invention.

FIG. 9 is a sectional view showing a ninth embodiment according to the present invention.

FIG. 10 is a sectional view showing a tenth embodiment of the present invention.

FIG. 11 is a sectional view showing an eleventh embodiment of the present invention.

FIG. 12 is a diagram showing a relationship between a luminance half time and a driving time under constant current driving for devices using a heat dissipation layer having various thermal conductivities.

FIG. 13 is a sectional view of a conventional organic EL device.

FIG. 14 is a sectional view of a conventional organic EL device.

[Explanation of symbols]

101 substrate 102 reflective electrode 103 light emitting area 104 transparent electrode 105 protective film 106 Light extraction surface

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/14 H05B 33/14 A 33/22 33/22 Z 33/24 33/24 33/28 33 / 28 H05K 7/20 H05K 7/20 BF term (reference) 3K007 AB14 BA06 CB01 CB03 CC01 DA01 DB03 EA01 EA04 EB00 5C094 AA03 AA33 AA35 AA37 AA55 BA03 BA27 CA19 DA07 DA09 DA13 DA15 FB20 FB20 FB20 FB20 FA02 ED02 FA02 ED02 FA02 ED02 FA02 ED02 FA02 ED02 JA08 JA20 5E322 AA11 FA04

Claims (10)

[Claims] 1. At least a first electrode, a light emitting region containing an organic material, and a second electrode are sequentially formed on a substrate, and an insulating heat dissipation layer is provided between the substrate and the first electrode. A light emitting device, wherein the heat dissipation layer has a thermal conductivity of 50 W / mK or more. 2. The second electrode is transparent or semi-transparent,
The light emitting device according to claim 1, wherein light is extracted from the second electrode side. 3. A scattering layer and an insulating heat dissipation layer are sequentially formed on the substrate between the substrate and the first electrode, and the surface of the scattering layer is planarized by the heat dissipation layer. The light emitting device according to claim 1. 4. The light emitting device according to claim 1, wherein the heat dissipation layer has a film thickness of 15 nm or more. 5. The light emitting device according to claim 1, wherein the heat dissipation layer also serves as a reflection layer. 6. The light emitting device according to claim 1, wherein the heat dissipation layer is a multilayer film. 7. A substrate, on which at least a first electrode, a light emitting region containing an organic material, and a second electrode are sequentially formed, and an insulating heat dissipation layer is provided on the substrate and the second electrode. A light emitting device in which the heat dissipation layer has a thermal conductivity of 50 W / mK or more. 8. The light emitting device according to claim 1, wherein the heat dissipation layer has a compound containing at least aluminum, magnesium, silicon, and carbon. 9. The heat dissipation layer is at least aluminum nitride, diamond-like carbon, magnesium oxide,
Alternatively, it contains silicon carbide.
The light emitting device according to any one of 1. 10. A display device in which a drive element for driving the light emitting element is added to the light emitting element according to any one of claims 1 to 9.