JP2003017273A - Display device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that is capable of display in high luminance and its manufacturing method. SOLUTION: The display device comprises a first electrode 201 made of a light reflecting material, a second electrode 108 made of a light transmission material, and an organic EL layer 107 that is pinched by these first electrode 201 and second electrode 108. A reflecting wall 202 for reflecting the emitting- light h emitted in the organic EL layer 107 toward the second electrode 201 side is provided in the surroundings of the organic EL layer 107. This reflecting wall 202 is constructed as an inner circumference wall formed in a concave shape of the first electrode 201.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and a method for manufacturing the display device, and more particularly to a display device having a light emitting layer sandwiched between electrodes and a method for manufacturing the display device.

[0002]

2. Description of the Related Art Electroluminescence of organic materials (e
An organic EL element utilizing luminescence (hereinafter referred to as EL) is drawing attention as a light emitting element capable of high-luminance light emission by low-voltage direct current driving. FIG. 5 shows an energy band diagram of the organic EL element. As shown in this figure,
The organic EL element is a carrier injection type electroluminescent element,
An organic EL layer 505 is sandwiched between an anode 501 and a cathode 503 having different work functions. The organic EL layer 505 is
It is composed of a plurality of layers having different carrier transport properties, for example, the anode 5
When the hole transport layer 505a, the light emitting layer 505b and the electron transport layer 505c are thinly deposited from the 01 side, when the hole transport layer also serves as the light emitting layer, and when the electron transport layer also serves as the light emitting layer. Yes, it is manufactured in various forms depending on the design with at least the light emitting layer.

In the light emitting process of such an organic EL element, holes injected from the anode 501 and electrons injected from the cathode 503 are recombined in the light emitting layer 505b, and excitons are accompanied by this recombination. Is generated and light is emitted when the excitons are deactivated.

FIG. 6 is a cross-sectional view of an essential part showing an example of a display device using the above-mentioned organic EL element. The display device shown in this figure has a thin film transi
stor: hereinafter referred to as TFT) is an active matrix type display device, in which T is formed on the supporting substrate 101.
A TFT layer 102 on which an FT (not shown) is formed is provided. Then, the first electrode 10 serving as an anode or a cathode (for example, an anode in this case) of the organic EL element is formed on the flattening insulating film 103 formed so as to cover the TFT layer 102.
4 are formed. The first electrode 104 is formed by patterning a conductive film having light reflectivity for each pixel, and is connected to the power source of the TFT through a contact hole (not shown) formed in the planarization insulating film 103.

An insulating film 105 is patterned on the flattening insulating film 103 so as to cover the peripheral portion of each first electrode 104. The insulating film 105 is made of a transparent material such as silicon oxide, and has an opening 105a that exposes only a portion of the surface of the first electrode 104 that contributes to light emission.
Are formed. Then, the opening 10 of the insulating film 105
The organic EL layer 1 is formed on the first electrode 104 exposed from 5a.
07 is provided. The organic EL layer 107 is provided so that the edge is overlapped with the opening edge portion of the insulating film 105 so as to completely cover the first electrode 104 exposed from the opening 105a of the insulating film 105. . Although illustration is omitted here, as described with reference to FIG.
The organic EL layer 107 is composed of a plurality of layers including at least a light emitting layer. In addition, the organic EL layer 107
Are formed by vapor deposition on a mask arranged above the substrate 101.

A second electrode 108 serving as an anode or a cathode (here, for example, a cathode) is formed above the substrate 101 so as to cover the organic EL layer 107. The second electrode 108 is made of a conductive material having a light-transmitting property, is formed in a solid film shape as an electrode common to the pixels, and is formed by the insulating film 105 and the organic EL layer 107 as a first electrode.
Insulation with the electrode 104 is secured.

In the display device 6 thus constructed, a voltage is applied to the second electrode 108, and the TFT layer 1
By applying a voltage to the first electrode 104 of each pixel by driving the TFT formed on the TFT 02, emitted light h is generated in the organic EL layer 107 of each pixel selected by the TFT, and this emitted light h is transmitted. It is taken out from the second electrode 108 side made of a conductive material.

[0008]

By the way, in the organic EL element provided in the display device 6 having the above-described structure, singlet excitation is caused by recombination of electrons and holes in the light emitting layer of the organic EL layer 107. And triplet excitons are generated, of which the generation efficiency of singlet excitons that contribute to light emission, that is, the internal quantum efficiency for injected charges is 2
It is about 5%. Further, the emitted light h generated in the light emitting layer is isotropically emitted in all directions. Therefore, when the insulating film 105 is made of a transparent material as described above,
The emission light h ′ emitted parallel to the surface direction of the organic EL layer 107 as shown by the chain line arrow in the figure is the organic EL layer 1 as it is.
07 penetrates into the insulating film 105 arranged around and becomes leakage light. Therefore, out of the emitted light h, h ′ generated in the light emitting layer, the extraction efficiency of the emitted light h that is actually emitted to the outside and contributes to the display (so-called external quantum efficiency).
Is about 20%. That is, in the display device using the organic EL element, the quantum efficiency for charge injection is 5%.
It's just a degree.

In a display device using such an organic EL element, in order to improve the brightness, it is effective to increase the amount of singlet excitons generated by increasing the current flowing between the electrodes. . However, there is a problem in that the larger the value of the current passed through the organic EL element, the faster the deterioration of the organic EL layer 107 and the shorter the life of the display device.

Therefore, according to the present invention, the efficiency of extracting emitted light (external quantum efficiency) is improved without increasing the current value, whereby the display can be improved in luminance while ensuring the life of the display device. An object of the present invention is to provide a device and a manufacturing method thereof.

[0011]

The display device of the present invention for solving the above-mentioned problems includes a first light-reflecting material.
In a display device including an electrode, a second electrode made of a light transmissive material, and a light emitting layer sandwiched between the first electrode and the second electrode, the light emitting layer is formed around the light emitting layer. It is characterized in that a reflective wall surface for reflecting light to the second electrode side is provided. This reflection wall surface is assumed to be configured as a part of the first electrode.

In the display device having such a structure, of the emitted light generated in the light emitting layer and emitted in all directions, the light emitted in the surface direction of the light emitting layer is reflected by the light emitting layer. It is reflected by the wall surface toward the second electrode. Therefore, the emitted light emitted in the above-mentioned direction is emitted together with the emitted light emitted to the second electrode side and the emitted light emitted to the first electrode side made of the light reflecting material and reflected by the first electrode. , Is taken out from the side of the second electrode made of a light transmissive material. Therefore, the extraction efficiency (external quantum efficiency) of the emitted light generated in the light emitting layer from the second electrode side is improved.

The present invention is also a method of manufacturing such a display device, in which a concave portion having a forward tapered inner peripheral surface is formed on the surface of the first electrode made of a light-reflecting material.
It is characterized in that a light emitting layer is formed in the recess of the electrode, and a second electrode made of a light transmissive material is formed on the light emitting layer while maintaining insulation between the light emitting layer and the first electrode. When forming the recess in the first electrode, the first electrode is isotropically etched using the resist pattern as a mask.

In such a manufacturing method, since the light emitting layer is formed in the recess of the first electrode, the inner peripheral surface of the side peripheral wall of the first electrode is arranged around the light emitting layer. Since this inner peripheral surface has a forward tapered shape, it is directed toward the second electrode formed on the light emitting layer. Moreover, since the first electrode is made of a light-reflecting material, the inner peripheral surface serves as a reflection wall surface for reflecting the light generated in the light emitting layer to the second electrode side.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method for manufacturing a display device and a display device according to the present invention will be described below in detail with reference to the drawings. Note that, in the present embodiment, as an example, as shown in FIG. 1, organic EL elements as light emitting elements are formed in an array on the supporting substrate 101, and emitted light h from each light emitting portion 1a on which the organic EL elements are formed is emitted. The present invention is applied to an active matrix drive type display device in which a TFT is provided for each pixel in which each light emitting portion 1a is arranged, among the top emission type display device in which is taken out from the side opposite to the supporting substrate 101. The case will be described. However, the present invention is not limited to the one using an organic EL element as a light emitting element, and is widely applicable to a display device using a self-luminous light emitting element such as an inorganic electroluminescent element. The display method is not limited to the top emission method, and may be a transmission method in which emitted light is extracted from the supporting substrate 101 side, and the drive method is not limited to the active matrix method.
Passive method is also acceptable.

Further, in each of the drawings used for the description, the dimensions, shapes and arrangement relationships thereof are schematically shown to the extent that the present invention can be understood, and the same components are denoted by the same reference numerals. The overlapping description will be omitted. Furthermore, the materials used and the numerical conditions such as the amount thereof, the treatment time, the treatment temperature, and the film thickness mentioned in the following description are only preferable examples within the scope of the present invention. Therefore, the invention according to this application is not limited only to these conditions.

FIG. 2 is a schematic sectional view of an essential part showing an example of the display device of the present invention, and FIG. 3 is an enlarged sectional view of the essential part of FIG. In the display device 1 shown in these figures, the same components as those of the conventional display device described with reference to FIG. 6 are designated by the same reference numerals, and duplicate description will be omitted.

The difference between the display device 1 shown in these figures and the conventional display device described with reference to FIG.
It is assumed that the electrode 201 has a shape and other components are similar to those of the conventional display device.

The first electrode 201 is formed by patterning a light-reflecting material film on a pixel-by-pixel basis. In particular, the peripheral portion of the first electrode 201 is formed into a sidewall shape projecting to the side opposite to the support substrate 101 over the entire circumference. That is, the first electrode 201 is formed in a concave shape having a side peripheral wall portion. Further, the inner peripheral surface of the side peripheral wall portion of the first electrode 201 is formed in a forward taper shape such that the concave opening width of the first electrode 201 is gradually narrowed toward the bottom thereof, and is configured as a reflection wall surface 202. ing. The peripheral portion of the first electrode 201 is preferably formed into a side wall shape projecting to the side opposite to the support substrate 101 over the entire circumference, but the present invention is not limited to this, and a part of the peripheral edge may be formed. It may be formed in a side wall shape protruding to the side opposite to the support substrate 101.

As the light-reflecting material forming the first electrode 201, chromium (Cr) or the like can be preferably used. Then, when the first electrode 201 is used as an anode, a material having a high work function is selected from such light reflecting materials, and when the first electrode 201 is used as a cathode, Lower materials will be selected.

The insulating film 105 covering the periphery of the first electrode 201 formed in this manner covers the periphery of the first electrode 201 including the side peripheral wall portion of the first electrode 201, and
Opening 105 for exposing the bottom of the concave first electrode 201
a. In addition, it is preferable that the bottom edge of the opening 105a reaches the concave bottom of the first electrode 201. As a result, the organic EL layer 1 described next
The edge of 07 is easily overlapped on the edge of the insulating film 105 without interruption.

The organic EL including at least a light emitting layer is formed on the first electrode 201 exposed from the opening 105a.
A layer 107 is provided. That is, this organic EL layer 1
The reflective wall surface 202 formed of the inner peripheral surface of the side peripheral wall portion of the first electrode 201 is arranged so as to surround 07. Note that, as described above, the organic EL layer 107 is provided so that its edge is overlapped with the edge of the insulating film 105.

Further, on the support substrate 101 having the first electrode 202 as described above, the insulating film 105 and the organic film 107 ensure light insulation with respect to the first electrode 202. A second electrode 108 made of a material is provided. As the light transmissive material forming the second electrode 108, for example, when the second electrode 108 is used as a cathode, a material having a low work function such as Mg-Ag (magnesium-silver) is selected, Second electrode 108
When used as an anode, ITO (Indium Tin
A material with a high work function such as Oxide) is selected.

Here, the reflection wall surface 202 of the first electrode 201
The taper shape is formed at an angle so that the emitted light which is generated in the organic EL layer 107 and is incident on the reflecting surface 202 is reflected to the second electrode 108 side. Also,
The height t1 of the reflection wall surface 202 is such that the emitted light h generated in the organic EL layer 107 and emitted in the surface direction of the organic EL layer 107 is effectively reflected to the second electrode 108 side.
It is assumed that the film thickness is equal to or larger than the film thickness t2 of the L layer 107. For example, the film thickness t2 of the organic EL layer 107 is 100 n
When it is about m, the height t1 of the reflection wall surface 202 is 100.
It is set to be equal to or larger than nm, and here, as an example, it is set to be 200 nm.

The taper shape of the reflection wall surface 202 is the first
In the case of the shape obtained by isotropically etching the electrode material from above, the taper angle of the reflection wall surface 202 is not constant but changes in the depth direction. Therefore, the reflection wall surface 2
By appropriately selecting the height t1 of 02, the organic EL layer 1
The emitted light h generated in 07 and emitted in the surface direction of the organic EL layer 107 is set to be effectively reflected to the second electrode 108 side.

In the display device 1 having such a structure,
The organic EL layer 107 includes the first electrode 201 and the second electrode 108.
The portion that directly sandwiches is the light emitting portion 1a. And
In the display device 1, of the emitted light h, h ′ generated in the light emitting layer (not shown) of the organic EL layer 107 and emitted in all directions, as shown by the chain line in FIG. The light h ′ emitted in parallel with is reflected by the reflection wall surface 202 arranged around the organic EL layer 107 toward the second electrode 108 side. Therefore, the emitted light h ′ emitted in the above-described direction is emitted to the second electrode 108 side or emitted to the first electrode 201 side made of a light reflecting material and reflected by the first electrode 201. The emitted light h is extracted from the second electrode 108 made of a light transmissive material. Therefore, the extraction efficiency (external quantum efficiency) of the emitted light h, h ′ generated in the light emitting layer of the organic EL layer 107 from the second electrode 108 side is improved as compared with the display device in which the reflective wall surface 202 is not provided. It is possible to let

In particular, when the peripheral portion of the first electrode 201 patterned for each pixel is formed in a side wall shape projecting to the side opposite to the support substrate 101 over the entire circumference, the organic EL layer 107. Since the light h ′ emitted in all the surface directions of is reflected on the second electrode 108 side,
It becomes possible to most effectively take out the emitted lights h and h ′ generated in the light emitting layer of the organic EL layer 107 from the second electrode 108 side.

As a result of the above, it is possible to perform display with higher brightness without increasing the current value, that is, without accelerating the deterioration of the organic EL layer. In addition, since it is possible to secure a certain level of brightness by driving with a lower current value, it is possible to suppress deterioration of the organic EL layer and to achieve a longer life of the display device.

Next, the procedure for manufacturing the display device having the structure described with reference to FIGS. 2 and 3 will be described as an example of the method for manufacturing the display device of the present invention.

First, as shown in FIG. 4A, a TFT layer 102 formed by forming TFTs (not shown here) is provided on a supporting substrate 101 made of, for example, quartz glass,
The upper portion of the TFT layer 102 is covered with the flattening insulating film 103. Then, the flattening insulating film 103 is etched using a resist pattern formed by a lithography method of applying resist, exposing and developing as a mask, and contact holes not shown here are formed in the TFTs provided in each pixel. Is formed on the planarization insulating film 103.

After that, a conductive film 2 for forming a first electrode to be an anode or a cathode is formed on the flattening insulating film 103.
01a is formed. Here, the first electrode is configured as an anode, and the conductive film 2 made of a material having a high work function and light reflectivity, such as a Cr (chrome) film, is used.
01a is formed into a film. The conductive film 201 is formed by, for example, a sputtering method. In addition, the conductive film 201a
The film thickness t3 of the first electrode is
It is set to a value that is combined with the height required as a reflection wall surface configured as a part of the electrode, and here, for example, 300 n
The film thickness is set to m.

Next, a resist pattern (not shown) is formed on the conductive film 201a by a lithography method. Then, the conductive film 201a is patterned by etching using this resist pattern as a mask. At this time, each conductive film 201a is patterned in each pixel shape, and each TFT is similarly connected to a TFT provided in each pixel through a contact hole (not shown) formed in the interlayer insulating film 103. It will be formed in the state of

Next, as shown in FIG. 4B, the conductive film 2
A resist pattern 301 is formed by a lithography process on the support substrate 101 on which 01a is patterned. The resist pattern 301 covers the periphery of the conductive film 201a and is formed on the conductive film 201a.
It is assumed that the opening portion 301a has a shape smaller than that of the opening portion 301a.

After that, as shown in FIG. 4C, the conductive film 201a is isotropically etched using the resist pattern 301 as a mask. At this time, half etching is performed so that the etching depth is smaller than the film thickness t3 of the conductive film 201a, that is, the conductive film 201a is left on the etching bottom surface. Here, the etching depth is about 200 nm, and the conductive film 201 having a film thickness of 100 nm is formed on the bottom of the etching.
Let's leave a.

By the isotropic etching as described above, the first concave portion having a concave portion on the upper surface side of the conductive film 201a is formed.
The electrode 201 is obtained. The first electrode 201 has a side wall portion whose peripheral edge is projected upward over the entire circumference, and the inner peripheral surface of the side wall portion serves as a forward tapered reflection wall surface 202.

The isotropic etching is performed by the conductive film 2
It is preferable to perform wet etching in order to suppress the etching damage to the etching surface of 01a, that is, the surface of the first electrode 201.
Therefore, here, for example, "ETCH-1" (trade name) manufactured by Sanyo Kasei Co., Ltd. is used as an etching solution, and the conductive film 201a made of Cr is wet-etched.

After the above, as shown in FIG. 4 (4), the first
The insulating film 1 is formed on the supporting substrate 101 on which the electrode 201 is formed.
05 is patterned. The insulating film 105 is made of, for example, silicon oxide (SiO ₂ ), covers the peripheral edge of the first electrode 201 including the reflection wall surface 202 of the first electrode 201, and exposes the bottom surface portion of the first electrode 201.
5a.

When the insulating film 105 having such a shape is formed, first, CVD (chemical vapor deposition) is performed.
By the method, an insulating film 105 made of silicon oxide and having a film thickness of 800 nm is formed above the supporting substrate 101. still,
The film thickness of the insulating film 105 is appropriately selected depending on the material forming the insulating film 105 so that the insulating property between the first electrode 201 and the second electrode described below can be sufficiently ensured.

Next, a resist pattern (not shown here) is formed on the insulating film 105 by a lithography method. After that, the insulating film 105 is isotropically etched by using this resist pattern as a mask. This etching is preferably wet etching in order to suppress damage to the first electrode 201 due to etching. Therefore, here, hydrofluoric acid (H
F) The insulating film 105 made of silicon oxide is wet-etched using a mixed acid of an aqueous solution and an ammonium fluoride (NH ₄ F) aqueous solution as an etching solution. As a result, the opening 10 reaching the first electrode 201 is formed in the insulating film 105.
5a is formed.

Thereafter, the washed support substrate 101 is
It is installed in a vacuum vapor deposition device for forming an organic EL layer. Then, a vapor deposition mask, not shown here, is placed on the support substrate 101. This vapor deposition mask has, for example, a stripe-shaped opening, the opening is superposed on the opening 105a, and the insulating film 10 is provided in the opening of the vapor deposition mask.
It is arranged above the support substrate 101 so that the opening 105a formed in 5 can be surely accommodated.

In this state, a triphenylamine derivative (N, N-diphenyl-N, N-bis (3-methylphenyl) -1,1-biphenyl-4,4-, which serves as a hole transport layer by vacuum deposition, is formed. Diamine: TPD) is formed by vapor deposition to a film thickness of about 50 nm.

Subsequently, in the same vapor deposition apparatus, an aluminum quinolinol complex (tris (8
-Hydroxyquinolinol) aluminum: Alq3)
Is vapor-deposited to a film thickness of 50 nm.

Here, the "hole transport layer" means that a large number of holes can be injected from the hole injection electrode (anode) having a large work function, and the injected holes can move in the film. ,
It is assumed that the thin film layer has a property that it is difficult to inject electrons, or it is possible to inject electrons but it is difficult to move in the film. The "electron transport layer" is capable of injecting a large amount of electrons from an electron injecting electrode (cathode) having a small work function, and the injected electrons can move through the film, but it is difficult to inject holes. Alternatively, it is assumed that the thin film layer has a property that it is difficult to move in the film even if it can be injected. The first
When the electrode 104 is formed as a cathode, the hole transport layer, the electron transport layer, the light emitting layer, and the like that form the organic EL layer 111 are laminated in an appropriately selected order.

As described above, the organic EL layer 1 having a film thickness of 100 nm is formed by laminating the hole transport layer and the electron transport light emitting layer.
07 is formed. The organic EL layer 107 is the insulating film 10
5 is laminated on the concave bottom surface of the first electrode 201 so as to be in contact with the first electrode 201 on the bottom surface of the opening 105a. Then, the side wall portion of the first electrode 201 is arranged around the organic EL layer 107.

Next, after removing the vapor deposition mask from the support substrate 101, the second electrode 10 in the form of a solid film is formed on the organic EL layer 107 by vacuum vapor deposition (for example, resistance heating vapor deposition).
8 is formed. The second electrode 108 serves as an anode or a cathode. When the first electrode 201 is an anode, it is formed as a cathode, and when the first electrode 201 is a cathode, it is formed as an anode. Here, since the first electrode 201 is configured as an anode, the second electrode 108 is configured as a cathode made of a material having a low work function, and has a work function such as Mg-Ag (alloy of magnesium and silver). Therefore, a material having low light transmittance and light transmittance is used.

As described above, the light emitting element (organic EL element) 109 in which the organic EL layer 107 is sandwiched between the first electrode 201 serving as the anode and the second electrode 108 serving as the cathode is provided for each pixel. Form. Although illustration is omitted here, after the light emitting element 109 is formed, a sealing step of the light emitting element 109 for preventing the deterioration of the organic EL layer 107 is performed.

As described above, the display device 1 having the configuration described with reference to FIGS. 2 and 3 is obtained. According to such a manufacturing method, the reflective wall surface 202 for reflecting the emitted light h generated in the organic EL layer 107 to the second electrode 108 side can be formed only by adding a mask step and an etching step.
The display device 1 provided around the layer 107 is obtained. Therefore, without increasing the number of parts, that is, the increase in manufacturing cost is suppressed to the minimum, the display device 1 having the above-described configuration is provided.
It becomes possible to obtain

In the above embodiment, the light emitting element is composed of a single color organic EL element. However, by repeating the organic EL layer forming step a plurality of times, a full color organic EL element having RGB is used. It can also be applied to existing displays. In the above embodiment, a TFT (thin film transistor) is provided on the support substrate 101, and the TFT
The case where the present invention is applied to the active matrix type display device in which the first electrode is connected to is explained. For this reason,
The second electrode 108 was formed as a solid film. However, the present invention is not limited to this, and for example, a passive matrix method in which a plurality of second electrodes are arranged in a stripe shape in a state of being orthogonal to a first electrode arranged in a stripe shape is used. It is also applicable to a display device. Further, the shapes of the first electrode and the second electrode are not limited to the stripe shape, and may be formed in a fine pattern of various shapes.

However, when the first electrode has a continuous shape over a plurality of pixels, it is preferable to provide a concave portion for each portion of the first electrode corresponding to each pixel. By molding the first electrode in such a shape, the organic EL corresponding to each pixel is formed.
It is possible to provide a reflective wall surface that surrounds the entire circumference of the layer portion, and it is possible to most effectively extract the light generated in the organic EL layer from the second electrode side.

[0050]

As described above, according to the display device of the present invention, it is possible to improve the extraction efficiency (external quantum efficiency) of emitted light generated in the light emitting layer. Therefore, in the display device using the organic EL element having the light emitting layer, it is possible to improve the luminance without increasing the driving current, that is, while suppressing the deterioration of the element, and to reduce the current with less current. By driving the display device, the life of the display device can be extended. Further, according to the manufacturing method of the display device of the present invention, without increasing the number of parts, the increase of the manufacturing cost can be suppressed to a minimum by merely adding the mask process and the etching process, and the light is reflected around the light emitting layer. It is possible to obtain a high-luminance, long-life display device in which a wall surface is arranged.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a display device to which the present invention is applied.

FIG. 2 is a cross-sectional view of essential parts showing an example of a display device of the present invention.

FIG. 3 is an enlarged cross-sectional view in which a main part of FIG. 2 is further enlarged.

FIG. 4 is a sectional process diagram for explaining the manufacturing method for the display device shown in FIGS. 2 and 3.

FIG. 5 is an energy band diagram of an organic EL element.

FIG. 6 is an enlarged sectional view of an essential part for explaining an example of a conventional display device.

[Explanation of symbols]

1 ... Display device, 101 ... Support substrate, 107 ... Organic EL layer (light emitting layer), 108 ... Second electrode, 201 ... First electrode, 2
02 ... Reflective wall surface, h, h '... Emitted light

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/14 H05B 33/14 A 33/22 33/22 Z F term (reference) 3K007 AB02 AB05 AB11 AB18 BA06 CB01 CC01 DA01 DB03 EB00 FA01 5C094 AA10 AA22 AA31 AA43 AA48 BA27 CA19 DA13 DB01 DB04 EA04 EA05 EA06 ED11 FA04 FB01 FB02 FB12 FB20 GB10 5G435 AA03 AA14 AA17 BB05 CC09 FF03 HH12 HH14 KK05

Claims (5)

[Claims] 1. A first electrode made of a light-reflecting material, a second electrode made of a light-transmitting material, and the first electrode and the second electrode.
In a display device including a light emitting layer sandwiched between electrodes, a reflective wall surface for reflecting light generated in the light emitting layer to the second electrode side is provided around the light emitting layer. A display device characterized by. 2. The display device according to claim 1, wherein the reflection wall surface is configured as a part of the first electrode. 3. The display device according to claim 1, wherein the first electrode is provided on a supporting substrate, and the second electrode is provided above the supporting substrate via the first electrode and the light emitting layer. A display device characterized by being. 4. A step of forming a concave portion having a forward tapered inner peripheral surface on the surface of a first electrode made of a light-reflecting material; and a step of forming a light emitting layer in the concave portion of the first electrode. And a step of forming a second electrode made of a light transmissive material on the light emitting layer while maintaining insulation between the light emitting layer and the first electrode. 5. The method for manufacturing a display device according to claim 4, wherein when the recess is formed in the first electrode, the first electrode is isotropically etched using a resist pattern as a mask. And a method for manufacturing a display device.