JP2003157965A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device which can efficiently utilize light, emitting light having a narrow spectrum width. SOLUTION: The light emitting device 100 comprises a substrate 10 and a light emitting element part formed on the substrate 10. The light emitting element part is composed of a light emitting layer 80 emitting light by electroluminescence, a first electrode 30 and a second electrode 50 for injecting electric charge into the light emitting layer 80, a third electrode 40 arranged to the light emitting layer 80 through a first insulation layer 64, and an optical member 88 transmitting the light generated at the light emitting layer 80 toward a prescribed direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device using EL (electroluminescence).

[0002]

BACKGROUND ART AND PROBLEMS TO BE SOLVED BY THE INVENTION EL
In an EL light-emitting element using (electroluminescence), light is emitted isotropically and the directivity is poor.
When viewed in a specific direction, the intensity of light is weak, and the emitted light cannot be used with high efficiency.

Further, although the conventional EL light emitting element has a wide spectrum width of emission wavelength and is used in some applications such as a display, it is used in applications such as optical communication where a light with a narrow spectrum width is required. Was unsuitable.

An object of the present invention is to provide a light emitting device which can efficiently use light and has a narrow spectral width of emission wavelength.

[0005]

A light emitting device according to the present invention includes a substrate and a light emitting element portion formed on the substrate, and the light emitting element portion includes a light emitting layer which emits light by electroluminescence. A first electrode and a second electrode for injecting an electric charge into the light emitting layer, a third electrode disposed on the light emitting layer via a first insulating layer, and a light generated in the light emitting layer being predetermined. An optical member for propagating in the direction of.

According to the light emitting device of the present invention, the light is emitted by applying a voltage between the first electrode and the second electrode in a state where a predetermined voltage is applied to the third electrode. A large number of electrons or holes are generated in the layer, and holes or electrons are injected into the light emitting layer. Thereby, the number of electrons or holes that contribute to light emission in the light emitting layer can be increased, and the light emission efficiency can be improved.

Further, in the light emitting device of the present invention, the optical member may form a photonic band gap or an incomplete photonic band. As a result, it is possible to obtain a light emitting device that can efficiently use light and has a narrow spectral width of the emission wavelength.

Here, the "imperfect photonic band" refers to a band in which the photonic band gap is formed only in a part of the directions or the photonic band gap is not formed in all the directions. For example, when the optical member is composed of a first medium layer and a second medium layer arranged around the first medium layer, the first medium layer and the second medium layer are When the difference in refractive index between the two is small, the photonic band gap may be formed in only a part of the optical member or may not be formed in all the directions. On the other hand, when the difference in the refractive index between the first medium layer and the second medium layer is large, a band gap may be formed in the optical member in all directions or in a specific direction.

According to the light emitting device of the present invention, electrons and holes are injected into the light emitting layer from a pair of electrode layers, that is, a cathode and an anode, respectively, and the electrons and holes are recombined in the light emitting layer. , Light is emitted when the molecule returns from the excited state to the ground state. Then, this light is emitted with two-dimensionally restricted spontaneous emission, has a very narrow emission spectrum width, and has high efficiency. The reason why light having such a property is obtained will be described separately for the case where the optical member can form a photonic band gap and the case where the optical member can form an incomplete photonic band.

(1) When the optical member can form a photonic band gap, the optical member forms a band for light. A state with a high density of states is obtained at the energy of the band edge of this band. Therefore, since the optical member is configured such that the energy level of the spectrum of the light emitted in the light emitting layer includes the energy level of the band edge, the light emission in the light emitting layer is the energy of the band edge. It tends to occur at the level. Thereby, it is possible to emit light having a wavelength corresponding to the energy level of a predetermined band edge and having a narrow spectrum width, and the light emission efficiency is good.

In this case, the optical member may include a defective portion. Here, the defective portion functions as a defect and is formed in a part of the optical member. In addition, in this specification, a "defect" means an optical defect. Further, the defect portion is set such that the energy level due to the defect exists within the energy level of a predetermined emission spectrum. According to this configuration, of the light generated in the light emitting layer, the light having the spectrum of the energy level corresponding to the inside of the photonic band gap of the optical member cannot propagate in the optical member and is caused by the defect. Only light having a spectrum corresponding to the energy level of the light can propagate in the optical member. Therefore,
Light with a very narrow emission spectrum width can be obtained with high efficiency.

(2) When the optical member can form an incomplete photonic band, the optical member forms a band for light. There are energy levels with a high density of states in this band. Here, the optical member is configured such that the energy level of the spectrum of the light emitted in the light emitting layer includes the energy level having a high density of states, so that the light emission in the light emitting layer is in this band. It tends to occur at the energy level at a given location. As a result, it is possible to emit light having a wavelength corresponding to the energy level of a predetermined portion of the band and having a narrow spectrum width, and the light emission efficiency is good.

The above-described light emitting device of the present invention can take the following various modes.

(A) The optical member may have a refractive index distribution that is periodic in at least one direction.

(B) At least a part of the light emitting layer can function as a part of the optical member. In this case, when the defective part is formed in a part of the optical member, at least a part of the light emitting layer can function as at least a part of the defective part.

Further, in this case, the light emitting layer may be composed of a plurality of columnar portions. Here, each of the plurality of columnar portions may be arranged with respect to the third electrode via the first insulating layer. In this case, the plurality of columnar parts can be arranged in a predetermined pattern.

(C) It may further include at least one of a hole transport / injection layer and an electron transport / injection layer.

In this case, the hole transport / injection layer or the electron transport / injection layer can function as at least a part of the optical member.

In this case, when the defective portion is formed in a part of the optical member, the hole transport / injection layer or the electron transport / injection layer can function as at least a portion of the defective portion. .

(D) The light emitting layer can be embedded in the opening.

(E) The light emitting layer may be disposed between the first electrode and the second electrode.

(F) The third electrode can be arranged between the first electrode and the second electrode.

In this case, the third electrode may be arranged with respect to the first electrode via a second insulating layer, and may be arranged with respect to the second electrode via a third insulating layer. it can.

(G) The light emitting layer may include an organic light emitting material as a light emitting material.

The above light emitting device can be applied to, for example, optical communication equipment.

Next, a part of materials that can be used for each part of the light emitting device according to the present invention will be illustrated. Of these materials, only some of the known materials are shown, and it goes without saying that materials other than those exemplified can be selected.

(Light Emitting Layer) The material of the light emitting layer is selected from known compounds in order to obtain light of a predetermined wavelength. The material of the light emitting layer may be either an organic compound or an inorganic compound, but is preferably an organic compound from the viewpoint of abundance of types and film forming properties.

Examples of such organic compounds include:
Aromatic diamine derivative (TPD), oxydiazole derivative (PBD), oxydiazole dimer (OXD) disclosed in JP-A-10-153967.
-8), distilarylene derivative (DSA), beryllium-benzoquinolinol complex (Bebq), triphenylamine derivative (MTDATA), rubrene, quinacridone, triazole derivative, polyphenylene, polyalkylfluorene, polyalkylthiophene, azomethine zinc complex, A porphyrin zinc complex, a benzoxazole zinc complex, a phenanthroline europium complex, etc. can be used.

More specifically, as the material for the organic light emitting layer, Japanese Patent Laid-Open Nos. 63-70257 and 63-1758 are used.
60, JP-A-2-135361, 2-1.
No. 35359, No. 3-152184, No. 8-248276, and No. 10-1539.
Known materials such as those described in Japanese Patent Publication No. 67 can be used. These compounds may be used alone or in combination of two or more.

The inorganic compounds include ZnS: Mn (red region), ZnS: TbOF (green region), SrS: C.
Examples include u, SrS: Ag, and SrS: Ce (blue region).

(Electrode Layer) The first electrode and the second electrode constituting the light emitting device of the present invention constitute a pair of electrode layers composed of a cathode and an anode. In this case, the first electrode and the second electrode function as either the anode or the cathode.

The cathode, that is, the electrode for injecting electrons into the light emitting layer has a small work function (for example, 4 eV).
Below) electron-injecting metals, alloy electrically conductive compounds and mixtures thereof can be used. As such an electrode substance, for example, the one disclosed in JP-A-8-248276 can be used.

The anode, that is, the electrode for injecting holes into the light emitting layer has a large work function (for example, 4e).
V or more) metal, alloy, electrically conductive compound, or a mixture thereof can be used. When an optically transparent material is used as the anode, CuI, ITO, SnO
₂ , a conductive transparent material such as ZnO or a metal such as Au can be used.

The third electrode may be Au or S, for example.
It can be formed from a metal such as i. When the surface of the third electrode is oxidized to form an insulating layer around the third electrode, Ta, Ti, Al or the like can be used.

(Hole Transport / Injection Layer) The light emitting device of the present invention may further include a hole transport / injection layer. The hole transport / injection layer has a function of transporting and injecting holes to the light emitting layer. This hole transport / injection layer is located between the anode and the light emitting layer. The hole transport / injection layer can be formed of an organic layer.

As a material for forming the hole transporting / injecting layer, a material used as a hole transporting / injecting material of a known photoconductive material or a hole transporting / injecting layer of an organic light emitting device is used. It can be used by selecting from known ones. As the material of the hole transport / injection layer, one having a function of injecting holes or a function of blocking electrons is used. Specific examples thereof include those disclosed in Japanese Patent Application Laid-Open No. 8-248276.

(Electron Transport / Injection Layer) The light emitting device of the present invention may further include an electron transport / injection layer. This electron transport / injection layer has a function of transporting and injecting electrons to the light emitting layer. The electron transport / injection layer is located between the cathode and the light emitting layer. The electron transporting / injecting layer can be formed from an organic layer.

In order for the organic layer to function as an electron transport / injection layer, it is sufficient that the organic layer has a function of transmitting electrons injected from the cathode to the light emitting layer, and such an organic layer is formed. The material for doing so can be selected from known substances. As a specific example, for example, Japanese Patent Laid-Open No. Hei 8
The one disclosed in Japanese Patent No. 248276 can be exemplified.

Each layer of the light emitting device of the present invention can be formed by a known method. For example, for each layer of the light emitting device, a suitable film forming method is selected depending on the material, and specifically, a vapor deposition method, a spin coating method, an LB method, an inkjet method and the like can be exemplified.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] (Device Structure) FIG. 1 is a sectional view schematically showing a light emitting device 100 according to the present embodiment. 2 is shown in FIG.
3 is a plan view schematically showing the light emitting device 100 shown in FIG. FIG. 3 is a diagram schematically showing a plane cut along a plane parallel to the XY plane along the line BB in FIG. 1. Note that FIG. 1 is a diagram schematically showing a cross section taken along the line AA of FIG. 2.

The light emitting device 100 has a light emitting element portion on the substrate 10. The light emitting element portion includes a first electrode 30 which is an anode,
It includes a light emitting layer 80, a third electrode 40, and a second electrode 50 that is a cathode. The first electrode 30, the light emitting layer 80, and the second electrode 50 are stacked on the substrate 10 in this order from the side closer to the substrate 10.

Further, in the light emitting device 100 of the present embodiment, as shown in FIG. 2, the protective layer 20 is formed so as to cover the light emitting element portion. By covering the light emitting element portion with the protective layer 20, the deterioration of the second electrode 50 can be prevented. In addition, the protective layer 20 is not formed on the entire light emitting device, and the first electrode 30, the second electrode 50, and the third electrode
It is formed so that a part of the surface of the electrode 40 is exposed (see FIG. 2). The exposed portions of these electrodes each function as an electrode extraction portion of each electrode.

Next, each component of the light emitting element section will be described in detail.

The first electrode 30 and the second electrode 50 form a pair of electrode layers and are provided for injecting charges (holes or electrons) into the light emitting layer 80.

The third electrode 40 is arranged between the first electrode 30 and the second electrode 50. A predetermined voltage is applied to the third electrode 40. The third electrode 40 is arranged on the light emitting layer 80 via the first insulating layer 64. Further, the third electrode 40 is arranged with respect to the first electrode 30 via the second insulating layer 62, and the second electrode 5
It is arranged with respect to 0 via the third insulating layer 66. The first insulating layer 64 mainly has a function of insulating the light emitting layer 80 and the third electrode 40. The second insulating layer 62 mainly has a function of insulating the first electrode 30 and the third electrode 40. The third insulating layer 66 mainly has a function of insulating the second electrode 50 and the third electrode 40. Examples of the material forming the first insulating layer 64, the second insulating layer 62, and the third insulating layer 66 include
The material is not particularly limited as long as it is an insulating material.

First electrode 30, second electrode 50, and third electrode
The electrodes 40 can be formed of the materials described above, respectively.

The light emitting layer 80 is made of a material that emits light by electroluminescence. The light emitting layer 80 is disposed between the first electrode 30 and the second electrode 50, as shown in FIG. The light emitting layer 80 can be formed from the above-mentioned materials.

The light emitting layer 80 is composed of a plurality of columnar portions, as shown in FIGS. Therefore, the plurality of columnar portions are arranged with respect to the third electrode 40 via the first insulating layer 64. In the light emitting device 100 of the present embodiment, as shown in FIG. 3, the plurality of columnar portions are arranged in a triangular lattice shape. The arrangement of the plurality of columnar portions is not limited to the triangular lattice shape, but may be arranged in a square lattice shape or a honeycomb shape, for example.

In the light emitting device 100, the light emitting layer 80 (plurality of columnar portions) functions as a part of the optical member 88 described later. The plurality of columnar portions are formed by embedding a light emitting material in the openings 22 (see FIGS. 8 and 9).

In the light emitting device 100 of the present embodiment, the light emitting layer 80 and the layers around the light emitting layer 80
The optical member 88 is configured. Specifically, as shown in FIG. 1, the optical member 88 includes a plurality of columnar portions forming the light emitting layer 80, a first insulating layer 64, a second insulating layer 62, and a third insulating layer 66 (hereinafter, referred to as “ The first insulating layer 64 etc. ”) and the third electrode 40. In order for the third electrode 40 to function as a component of the optical member 88, the third electrode 4
It is necessary that 0 be made of a material that does not absorb the light generated in the light emitting layer 80. Similarly, in the first insulating layer 64, the second insulating layer 62, and the third insulating layer 66, these layers are formed in the light emitting layer 80 in order to function as one component of the optical member 88. It must be made of a material that does not absorb light.

The optical member 88 has a refractive index distribution which is periodic in at least one direction and has a function of propagating the light generated in the light emitting layer 80 in a predetermined direction. In the light emitting device 100 of the present embodiment, as shown in FIG. 3, since the plurality of columnar parts forming the light emitting layer 80 are arranged in a triangular lattice pattern, the optical member 88 is arranged in the XY plane. a
It has a refractive index distribution that is periodic in the directions b, c, and c. Furthermore, the optical member 88 is in the XY plane.
It also has a periodic refractive index distribution in the d direction, the e direction, and the f direction.

The light generated in the light emitting layer 80 is confined in the optical member 88.

Specifically, the light emitting device 10 of the present embodiment
In 0, the optical member 88 is based on the photorefractive index difference between the light emitting layer 80 (plurality of columnar parts) and the layers around the light emitting layer 80 (the first insulating layer 64 and the third electrode 40). Nick band gaps or incomplete photonic bands can be formed. For example, when the difference in the refractive index between the light emitting layer 80 and the third electrode 40 is large, the photonic band gap may be formed in the light emitting layer 80 in all directions or in a specific direction. On the other hand, when the difference in refractive index between the light emitting layer 80 and the third electrode 40 is small, the optical member 88 is used.
In some cases, the photonic band gap may be formed only in some directions or may not be formed in all directions.

(Device Manufacturing Method) Next, FIGS.
A method of manufacturing the light emitting device 100 according to the present embodiment will be described with reference to FIG. FIG. 4, FIG. 6, FIG. 8, FIG. 10, and FIG. 12 are plan views schematically showing one manufacturing process of the light emitting device shown in FIG. In addition, FIG. 5, FIG. 7, FIG.
1 and 13 are respectively FIG. 4, FIG. 6, FIG. 8 and FIG.
It is a figure which shows 0 and the cross section in the AA line of FIG. 12 typically.

(1) First, as shown in FIGS. 4 and 5, the first electrode 30 is formed on the substrate 10 by the mask sputtering method. Subsequently, the second insulating layer 62 having a predetermined opening (not shown) is formed on the first electrode 30. This opening is formed by, for example, a photolithography process.

Then, the first insulating layer 64 is formed at a predetermined position on the second insulating layer 62. Specifically, the first insulating layer 64 is formed so as to surround the opening provided in the second insulating layer 62. Through the above steps, as shown in FIGS. 4 and 5, a plurality of openings 22 are formed in the region surrounded by the first insulating layer 64. This opening 2
2 is provided for arranging the light emitting layer 80 (plurality of columnar portions) in a later step (see FIGS. 10 and 11).

(2) Next, as shown in FIGS. 6 and 7, for example, mask sputtering is performed on the region 24 (see FIGS. 4 and 5) surrounded by the first insulating layer 64 and the second insulating layer 62. The third electrode 40 is formed by the method.

(3) Next, as shown in FIGS. 8 and 9, a third insulating layer 66 is formed on the third electrode 40 and the first insulating layer 64 by, for example, a mask sputtering method. The third insulating layer 66 can also be formed by a photolithography process or a printing technique.

(4) Next, as shown in FIGS. 10 and 11, a light emitting layer 80 is formed in the opening 22. The light emitting layer 80 is formed in the opening 2 by an inkjet method, for example.
2 is formed by embedding a light emitting material. The light emitting layer 80 is composed of a plurality of columnar portions arranged in a triangular lattice. By this step, the light emitting layer 80 (plurality of columnar portions)
And an optical member 88 including the layers around the light emitting layer 80 (the first insulating layer 64 and the like and the third electrode 40).

(5) Next, as shown in FIGS. 12 and 13, a second layer is formed on the light emitting layer 80 by, for example, a mask vapor deposition method.
The electrode 50 is formed. Subsequently, the protective layer 20 is formed over the entire surface except a part of the first electrode 30. This protective layer 20
Is formed so that a part of each electrode is exposed in order to form an electrode extraction portion of each electrode on the surfaces of the first electrode 30, the second electrode 50, and the third electrode 40. Through the above steps, the light emitting device 100 of this embodiment is obtained (see FIGS. 1 to 3).

(Device Operation) The light emitting device 100 according to the present embodiment emits light by the following mechanism.

First, a voltage is applied between the first electrode 30 and the second electrode 50 while a predetermined voltage is applied to the third electrode 40. Thereby, the first electrode 30 serving as the anode
Holes are injected into the light emitting layer 80, and electrons are injected into the light emitting layer 80 from the second electrode 50, which is a cathode, and a large amount of holes or electrons are generated in the light emitting layer 80.

Here, holes and electrons are recombined in the light emitting layer 80 to generate excitons, and light is generated when the excitons are deactivated. The light generated in the light emitting layer 80 is, for example, in a predetermined direction parallel to the XY plane (see FIGS. 1 to 3) after the optical member 88 restricts the propagation of the light in the XY plane. And emits.

As described above, in the light emitting device 100 of the present embodiment, only the light of the specific spectrum is emitted due to the two-dimensional photonic band gap or the incomplete photonic band formed by the optical member 88. Therefore, it has wavelength selectivity, has a narrow emission spectrum width, and has excellent directivity. The above optical member 88
Regarding the effects of the above, the light emitting device 100 of the present embodiment
This will be described in the section of action and effect (described later).

(Operation and Effect) Light emitting device 10 of the present embodiment
The main effects of 0 are listed below.

(A) Light emitting device 10 according to the present embodiment
According to 0, by applying a voltage between the first electrode 30 and the second electrode 50 in a state where a predetermined voltage is applied to the third electrode 40, electrons or holes are generated in the light emitting layer 80. When a large amount is generated, holes or electrons are injected into the light emitting layer. As a result, the number of electrons or holes that contribute to light emission in the light emitting layer 80 can be increased, and the light emission efficiency can be improved.

(B) Further, as described above, in the light emitting device 100 of the present embodiment, the light emitting layer 80 (plurality of columnar portions) and layers around the light emitting layer 80 (the first insulating layer 64 and the like and The optical member 88 can form a photonic band gap or an incomplete photonic band based on the difference in refractive index from the third electrode 40).

When the optical member 88 can form a photonic band gap, the optical member 88 forms a band for light. At a predetermined band edge energy within this band, a state with a high density of states can be obtained. Therefore, since the optical member 88 is configured such that the energy level of the spectrum of the light emitted in the light emitting layer 80 includes the energy level of this band edge, the emission of light in the light emitting layer 80 is the energy of this band edge. It tends to occur at the level. Thereby, having a wavelength corresponding to the energy level of a predetermined band edge,
In addition, light with a narrow spectrum width can be emitted, and the light emission efficiency is good.

On the other hand, when the optical member 88 can form an incomplete photonic band, the optical member 88 forms a band for light. There are energy levels with a high density of states in this band. Here, since the optical member 88 is configured such that the energy level of the spectrum of the light emitted in the light emitting layer 80 includes the energy level having a high density of states, the light emission in the light emitting layer 80 is in this band. It tends to occur at the energy level at a given location. As a result, it is possible to emit light having a wavelength corresponding to the energy level of a predetermined portion of the band and having a narrow spectrum width, and the light emission efficiency is good.

[Second Embodiment] (Device Structure) FIG. 14 is a sectional view schematically showing a light emitting device 200 according to the present embodiment. Figure 15 shows
FIG. 15 is a plan view schematically showing the light emitting device 200 shown in FIG. 14. FIG. 16 is a diagram schematically showing a plane cut along a plane parallel to the XY plane along the line BB in FIG. 14. In addition,
FIG. 14: is a figure which shows typically the cross section along the AA line of FIG.

In the light emitting device 200, as in the light emitting device 100 of the first embodiment, the light emitting layer 80 is composed of a plurality of columnar portions. On the other hand, in the light emitting device 200, mainly in the light emitting element portion, the optical member 188 includes the defective portion 28.
The structure is different from that of the light emitting device 100 of the first embodiment.

The defective portion 28 is formed in a part of the optical member 188 and functions as a defect. This defective portion 28
Is set so that the energy level due to this defect exists within the energy level of a predetermined emission spectrum. Specifically, the energy level caused by the defect formed by the defect portion 28 is formed to be the energy level corresponding to the emission spectrum of the light emitting layer 80 by current excitation.

The defective portion 28 has a columnar shape. On the other hand, the defect portion 28 is formed with a diameter different from that of the other columnar portions forming the light emitting layer 80. Specifically, in this light emitting device 200, the diameter of the cross section when the defect portion 28 is cut along a plane parallel to the XY plane is the light emitting layer 80.
Is formed larger than the diameter of the other columnar portion (columnar portion other than the defective portion 28) constituting the. In addition, the defect portion 28 is made of the same material as the other columnar portions forming the light emitting layer 80. That is, in the light emitting device 200, a part of the light emitting layer 80 functions as the defective portion 28. Other structures are almost the same as the light emitting device 100 shown in FIG.
The description is omitted.

(Device Manufacturing Method) In the manufacture of the light emitting device 200 of this embodiment, in order to form the defective portion 28, an opening having a diameter different from that of the other columnar portions constituting the light emitting layer 80 is formed. After that, except that the defect portion 28 is formed by embedding a light emitting material in the opening, the light emitting device 100 is substantially the same as the light emitting device 100 according to the first embodiment, and a description thereof will be omitted. Note that the defective portion 28 can be formed in the same step as the plurality of columnar portions forming the light emitting layer 80.

(Operation and Effect of Device) Among the operations of the light emitting device 200 of the present embodiment, the mechanism until light is generated in the light emitting layer 80 is the same as that of the light emitting device 100 of the first embodiment. is there. Therefore, according to the light emitting device 200, the light emitting device 100 according to the first embodiment.
Similarly, the number of electrons or holes that contribute to light emission in the light emitting layer 80 can be increased, and the light emission efficiency can be improved.

On the other hand, in the light emitting device 200 of the present embodiment, the defective portion 28 is formed in a part of the optical member 188 in the light emitting element portion. As described above, the defect portion 28 is set so that the energy level due to the defect exists within the energy level of the predetermined emission spectrum. As a result, of the light generated in the light emitting layer 80, the light having the spectrum of the energy level corresponding to the photonic band gap of the optical member 188 cannot propagate in the optical member 88 and the energy level caused by the defect is generated. Only light having a spectrum corresponding to can propagate in the optical member 88. Therefore, it is possible to obtain light with a very narrow emission spectrum width with high efficiency.

[Third Embodiment] (Device Structure) FIG. 17 is a sectional view schematically showing a light emitting device 300 according to the present embodiment.

In the light emitting device 300, the hole transport / injection layer 70 and the electron transport / injection layer 70 are further provided in the light emitting element section.
Except for including the injection layer 90, the light emitting device 100 shown in FIG.
It has the same structure as.

Hole Transport / Injection Layer 70 and Electron Transport /
The injection layer 90 functions as a part of the optical member 288 together with the light emitting layer 80. In the light emitting device 300 of the present embodiment, the hole transport / injection layer 70 is provided in the plurality of openings.
The light emitting layer 80 and the electron transporting / injecting layer 90 are sequentially embedded to form a plurality of columnar portions. That is, the optical member 288 includes a plurality of columnar portions including the hole transporting / injecting layer 70, the light emitting layer 80, and the electron transporting / injecting layer 90, and layers around the columnar portions (the first insulating layer 64 and the second insulating layer 64).
Insulating layer 62 and third insulating layer 66 and third electrode 40)
Composed of and. Like the light emitting layer 80, the hole transporting / injecting layer 70 and the electron transporting / injecting layer 90 are arranged on the third electrode 40 via the first insulating layer 64.

(Operation of Device, and Operation and Effect) Since the operation of the light emitting device 300 of the present embodiment is basically the same as the operation of the light emitting device 100 of the first embodiment, the description thereof is omitted. To do.

Further, in the light emitting device 300 of the present embodiment, since the hole transport / injection layer 70 and the electron transport / injection layer 90 are arranged in addition to the light emitting layer 80, the holes or electrons that contribute to light emission are emitted. The number can be increased. Thereby, the luminous efficiency can be further improved.

In the light emitting device 300 of the present embodiment, in addition to the light emitting layer 80, the hole transport / injection layer 70 is provided.
Although the case where both the electron transport / injection layer 90 and the electron transport / injection layer 90 are provided has been described, only one of the hole transport / injection layer 70 and the electron transport / injection layer 90 may be provided.

Further, in the light emitting device 300 of the present embodiment, a defective portion (not shown) can be provided as in the light emitting device 200 described above. In this case, the hole transporting / injecting layer 70 and the electron transporting / injecting layer 90 forming the defective portion function together with the light emitting layer 80 as a part of the defective portion. Also in this case, the above-described light emitting device 200
The same operation and effect can be obtained.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these, and various modes can be adopted within the scope of the gist of the invention.

In the light emitting device 100 of the present embodiment, the first electrode 30 (anode) is arranged on the substrate 10, and the second electrode 50 (cathode) is arranged in a layer above the first electrode 30. The case has been explained, or the second
The electrode 50 (cathode) is arranged on the substrate 10, and the first electrode 30 is provided via the light emitting layer 80 formed on the second electrode 50.
(Anode) can also be arranged.

[Brief description of drawings]

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

FIG. 2 is a plan view schematically showing the light emitting device shown in FIG.

FIG. 3 is a view schematically showing a plane cut along a plane parallel to the XY plane along the line BB in FIG.

FIG. 4 is a plan view schematically showing one manufacturing process of the light emitting device shown in FIG.

5 is a diagram schematically showing a cross section taken along line AA of FIG.

6 is a plan view schematically showing one manufacturing process of the light emitting device shown in FIG.

7 is a diagram schematically showing a cross section taken along line AA of FIG.

FIG. 8 is a plan view schematically showing one manufacturing process of the light emitting device shown in FIG.

9 is a diagram schematically showing a cross section taken along line AA of FIG.

10 is a plan view schematically showing one manufacturing process of the light emitting device shown in FIG.

11 is a diagram schematically showing a cross section taken along line AA of FIG.

FIG. 12 is a plan view schematically showing one manufacturing process of the light emitting device shown in FIG.

13 is a diagram schematically showing a cross section taken along line AA of FIG.

FIG. 14 is a sectional view schematically showing a light emitting device according to a second embodiment of the invention.

FIG. 15 is a plan view schematically showing the light emitting device shown in FIG.

16 is a diagram schematically showing a plane cut along a plane parallel to the XY plane along the line BB in FIG.

FIG. 17 is a sectional view schematically showing a light emitting device according to a third embodiment of the invention.

[Explanation of symbols]

10 substrates 20 Protective layer 22 opening 24 areas 28 Defects 30 First electrode 40 Third electrode 50 Second electrode 62 second insulating layer 64 first insulating layer 66 Third insulating layer 70 hole transport / injection layer 80 Light-emitting layer 88,188,288 Optical member 90 Electron transport / injection layer 100,200,300 Light emitting device

Continued front page    (72) Inventor Taketomi Uekawa             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation (72) Inventor Nobuo Oguchi             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation (72) Inventor Atsushi Harada             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation F-term (reference) 3K007 AB00 AB02 AB04 BA00 EA04                       EB00

Claims (21)

[Claims] 1. A substrate, and a light emitting element portion formed on the substrate, wherein the light emitting element portion includes a light emitting layer that generates light by electroluminescence, and a first light emitting layer for injecting charges into the light emitting layer. 1 electrode and 2nd
An electrode, and a third electrode disposed on the light emitting layer via a first insulating layer.
A light emitting device comprising: an electrode; and an optical member for propagating light generated in the light emitting layer in a predetermined direction. 2. The light emitting device according to claim 1, wherein the optical member can form a photonic band gap. 3. The defect according to claim 2, wherein the optical member includes a defect portion which is formed in a part of the optical member and is set so that an energy level due to the defect exists within an energy level of a predetermined emission spectrum. , Light emitting device. 4. The optical member according to claim 2, wherein the energy level of an emission spectrum of the light emitting layer includes an energy level of a band edge of a photonic bandgap formed by the optical member. Light emitting device. 5. The light emitting device according to claim 1, wherein the optical member can form an incomplete photonic band. 6. The light emitting device according to claim 5, wherein the optical member is configured such that an energy level of an emission spectrum of the light emitting layer includes an energy level of a band formed by the optical member. 7. The light-emitting device according to claim 1, wherein the light emitted from the light-emitting layer is emitted with a limited two-dimensional spontaneous emission. 8. The light emitting device according to claim 1, wherein the optical member has a periodic refractive index distribution in at least one direction. 9. The light emitting device according to claim 1, wherein at least a part of the light emitting layer functions as a part of the optical member. 10. The light emitting device according to claim 3, wherein at least a part of the light emitting layer functions as at least a part of the defective portion. 11. The method according to claim 9 or 10, The light emitting device, wherein the light emitting layer includes a plurality of columnar portions. 12. The light emitting device according to claim 11, wherein each of the plurality of columnar portions is arranged with respect to the third electrode via the first insulating layer. 13. The light emitting device according to claim 11, wherein the plurality of columnar portions are arranged in a predetermined pattern. 14. The light emitting device according to claim 1, further comprising at least one of a hole transport / injection layer and an electron transport / injection layer. 15. The light emitting device according to claim 14, wherein the hole transporting / injecting layer or the electron transporting / injecting layer functions as at least a part of the optical member. 16. The light emitting device according to claim 3, wherein the hole transporting / injecting layer or the electron transporting / injecting layer functions as at least a part of the defective portion. 17. The light emitting layer according to claim 1, wherein the light emitting layer is embedded in the opening.
Light emitting device. 18. The light-emitting device according to claim 1, wherein the light-emitting layer is arranged between the first electrode and the second electrode. 19. The light emitting device according to claim 1, wherein the third electrode is arranged between the first electrode and the second electrode. 20. The third electrode according to claim 19, wherein the third electrode is arranged with respect to the first electrode via a second insulating layer, and is arranged with respect to the second electrode via a third insulating layer. Light emitting device. 21. The light emitting device according to claim 1, wherein the light emitting layer contains an organic light emitting material as a light emitting material.