Patent Publication Number: US-2023157050-A1

Title: Display device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-185743, filed Nov. 15, 2021, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a display device. 
     BACKGROUND 
     In recent years, display devices comprising organic light-emitting diodes (OLEDs) applied thereto as display elements have been put to practical use. Display devices having a top emission structure includes a high-reflective electrode which increases the reflectivity to resonate light, that is, for example, a reflective electrode containing silver (Ag), and a transparent electrode having a large band gap and located on the high-reflective electrode, that is, for example, an anode (or anode electrode) containing indium tin oxide (ITO) or indium zinc oxide (ZnO). To increase the resolution of such a display device, for example, from 300 ppi to 3,000 ppi, dry etching, which can be used in microfabrication, may be employed for processing the display device. Note that wet dry etching is not suitable for such process. However, since it is difficult to process a reflective electrode containing silver (Ag) by dry etching, the reflective electrode needs to be formed of aluminum (Al) or the like. Then, again, it is also difficult to achieve electrical contact between aluminum (Al) and a transparent electrode, for example, indium tin oxide (ITO). Under these circumstances, between aluminum (Al) and the transparent electrode, for example, a conducting electrode having good electrical contact with the transparent electrode, for example, indium tin oxide (ITO) needs to be placed. However, such a conducting electrode having good electrical contact with the transparent electrode, for example, indium tin oxide (ITO) needs to be placed between aluminum (Al) and the transparent electrode, may cause lowering in reflectivity on the surface of the anode. As a result, the absorption of light during multiple reflections on the surface of the anode is increased, and therefore the light-emission efficiency of the display device can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram showing a configuration example of a display device according to the first embodiment. 
         FIG.  2    is a plan view of a configuration example of a pixel according to the first embodiment. 
         FIG.  3    is a cross-sectional view of the configuration example of a display element according to the first embodiment. 
         FIG.  4    is a cross-sectional view of a configuration example of a display element according to a comparative example. 
         FIG.  5    is a schematic diagram showing an example of a brightness-voltage curve. 
         FIG.  6    is a cross-sectional view showing a configuration example of a display element according to a modified example 1. 
         FIG.  7    is a cross-sectional view showing a configuration example of a display element according to a modified example 2. 
         FIG.  8    is a cross-sectional view showing a configuration example of a display element according to a modified example 3. 
         FIG.  9    is a cross-sectional view showing a configuration example of a display element according to a modified example 4. 
         FIG.  10    is a cross-sectional view showing a configuration example of a display element according to a modified example 5. 
         FIG.  11    is a cross-sectional view showing a configuration example of a display element according to the second embodiment. 
         FIG.  12    is a cross-sectional view showing a configuration example of a display element according to a modified example 6. 
         FIG.  13    is a cross-sectional view showing a configuration example of a display element according to a modified example 7. 
         FIG.  14    is a cross-sectional view showing a configuration example of a display element according to a modified example 8. 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, a display device comprises a base, a first insulating layer disposed on the base, a lower electrode disposed on the first insulating layer, an organic layer disposed on the lower electrode and including a light-emitting layer and an upper electrode disposed on the organic layer, and the lower electrode includes a conductive layer including a contact area disposed over an entire circumference thereof when viewed in plan view, a reflective layer disposed above the conductive layer on an inner side of the contact area, which reflects light and a transparent electrode located on the conductive layer and the reflective layer and in contact with the contact area. 
     According to another embodiment, a display device comprises a base, a first insulating layer disposed on the base, a lower electrode disposed on the first insulating layer, an organic layer disposed on the lower electrode and including a light-emitting layer and an upper electrode disposed on the organic layer, and the lower electrode includes a conductive layer, a reflective layer disposed on the conductive layer, which reflects light, and a transparent electrode disposed on the reflective layer, the transparent electrode is formed of indium tin oxide, and the reflective layer is formed of Al—Ni, Al—W alloy, Al—Mo alloy, Al—Ti alloy, Al—Ni—W, Al—Ni—Mo alloy or Al—Ni—Ti alloy. 
     Embodiments will be described hereinafter with reference to the accompanying drawings. 
     Note that, throughout the embodiments, common structural elements are denoted by the same symbols and redundant explanations are omitted. Further, the drawings are schematic diagrams to facilitate understanding of the embodiments, and the shapes, dimensions, ratios, and the like, may differ from actual conditions, but they may be redesigned as appropriate, taking into account the following descriptions and conventionally known technology. 
     Note that, in order to make the descriptions more easily understandable, some of the drawings illustrate an X axis, a Y axis and a Z axis orthogonal to each other. A direction along the X axis is referred to as an X direction or a first direction, a direction along the Y axis is referred to as a Y direction or a second direction and direction along the Z axis is referred to as a Z direction or a third direction. The first direction X, the second direction Y and the third direction Z may intersect each other at an angle other than 90 degrees. A length along the first direction X or the second direction Y may be referred to as a width, and the length along the third direction Z may be referred to as a thickness. In the following descriptions, a direction from a base  10  to a display element  20  may be referred to as “upward” (or simply “above”) and a direction from the display element  20  to the base  10  may be referred to as “downward” (or simply “below”). With such expressions as “a second layer above a first layer” and “a second layer below a first layer”, the second layer may be in contact with the first layer or may be remote from the first layer. A plane defined by the X axis (the first direction X) and the Y axis (the second direction Y) may be referred to as an X-Y plane, a plane defined by the X axis (the first direction X) and the Z axis (the third direction Z) may be referred to as an X-Z plane, and a plane defined by the Y axis (the second direction Y) and the Z axis (the third direction Z) may be referred to as an Y-Z plane. Further, viewing towards the X-Y plane is referred to as plan view. 
     First Embodiment 
     This embodiment is directed to a display device DSP is an organic electroluminescent display device comprising organic light-emitting diodes (OLEDs) as display elements, and is installed in televisions, personal computers, mobile terminals, cellular phones, and other devices. 
       FIG.  1    is a diagram showing a configuration example of the display device DSP of this embodiment. 
     The display device DSP comprises an insulating base  10 . The base  10  may be glass or a flexible resin film. Further, the display device DSP includes a display area DA in which images are displayed and a non-display area NDA surrounding the display area DA. 
     The display device DSP comprises, in the display area DA, a plurality of pixels PX arranged in a matrix along the first direction X and the second direction Y. 
     The pixels PX each comprise a plurality of sub-pixels SP 1 , SP 2  and SP 3 . For example, the pixels PX each contain a red sub-pixel SP 1 , a green sub-pixel SP 2  and a blue sub-pixel SP 3 . The pixels PX may additionally contain fourth or more sub-pixels in addition to the above-described three-color sub-pixels, of some other color such as white. 
     A configuration example of one sub-pixel SP contained in a pixel PX will be briefly described. That is, the sub-pixel SP comprises a pixel circuit  1  and a display element  20  driven and controlled by the pixel circuit  1 . The pixel circuit  1  comprises a pixel switch  2 , a drive transistor  3  and a capacitor  4 . The pixel switch  2  and drive transistor  3  are switching elements constituted by, for example, thin-film transistors. The switching elements include electrodes made of, for example, titanium(Ti)-aluminum (Al)-titanium(Ti). Note that the electrodes of the switching element may as well be formed of materials other than titanium(Ti)-aluminum(Al)-titanium(Ti). 
     As to the pixel switch  2 , the gate electrode is connected to the respective scanning line GL, the source electrode is connected to the respective signal line SL, and the drain electrode is connected to one of the electrodes which constitutes the capacitor  4  and the gate electrode of the drive transistor  3 . As to the drive transistor  3 , the source electrode is connected to the other electrode of the capacitor  4  and a power line PL, and the drain electrode is connected to the anode of the display element  2 . The cathode of the display element  20  is connected to a power feed line FL. Note that the configuration of the pixel circuit  1  is not limited to that of the example shown in the figure. 
     The display element  20  is an organic light emitting diode (OLED), which is a light-emitting element. For example, the sub-pixel SP 1  comprises a display element which emits light corresponding to red wavelengths, the sub-pixel SP 2  comprises a display element which emits light corresponding to green wavelengths, and the sub-pixel SP 3  comprises a display element which emits light corresponding to blue wavelengths. Note that the sub-pixels SP 1  to SP 3  may comprise a display element which emits light corresponding to white wavelengths. When the emission color of each of the display elements  20  is white, multicolor display can be realized by arranging color filters to oppose the display elements  20 , respectively. When the emission color of each of the display elements  20  is of ultraviolet light, multicolor display can be realized by arranging light conversion layers to oppose the display elements  20 . The configuration of the display elements  20  will be described later. 
       FIG.  2    is a plan view showing a configuration example of a pixel PX according this embodiment. 
       FIG.  2    shows only the configuration necessary for explanation. 
     The display device DSP comprises an insulating layer  12 , a lower electrode E 1  and the like. In the example shown in  FIG.  2   , the display device DSP comprises insulating layers  12  ( 1211 ,  1212 ,  1213 ,  1214 ,  1221  and  1222 ) and lower electrodes E 1  (E 11 , E 12  and E 13 ), and the like. 
     The lower electrodes E 1  are disposed in the sub-pixels SP. In the example shown in  FIG.  2   , the lower electrode E 1  includes lower electrodes E 11 , E 12  and E 13 . The lower electrode E 11  is disposed in the sub-pixel SP 1 . The lower electrode E 12  is disposed in the sub-pixel SP 2 . The lower electrode E 13  is disposed in the sub-pixel SP 3 . The lower electrodes E 11 , E 12  and E 13  are aligned along the first direction X. The lower electrodes E 1 , including the lower electrodes E 11  to E 13 , are electrodes disposed for each sub-pixel or each display element and may be referred to as pixel electrodes, anodes, anodes or the like. 
     The lower electrode E 1  (E 11 , E 12  and E 13 ) includes a transparent electrode TE (TE 1 , TE 2  and TE 3 ), a reflective layer (or reflective electrode) RL (RL 1 , RL 2  and RL 3 ) which reflects light, and a conductive layer (or conductive electrode) CDL (CDL 1 , CDL 2  and CDL 3 ) which has conductivity. In the example shown in  FIG.  2   , the conductive layer CDL is formed into a rectangular shape (oblong or quadrangular) in plan view. The conductive layer CDL may be formed into a shape other than a rectangular shape (oblong or quadrangular) in plan view. The conductive layer CDL is formed into a rectangular shape whose length along the second direction Y is greater than the length along the first direction X in plan view. The reflective layer RL is located above the conductive layer CDL and overlaps the conductive layer CDL. In the example shown in  FIG.  2   , the reflective layer RL is formed into a rectangular shape (or quadrangular) in plan view. Note that the reflective layer RL may be formed into a shape other than a rectangular shape (or quadrangular) in plan view. The reflective layer RL is formed into a rectangular shape whose length along the second direction Y is greater than that along the first direction X in plan view. The size (or area) of the reflective layer RL is less than the size (or area) of the conductive layer CDL in plan view. In the example shown in  FIG.  2   , the reflective layer RL overlaps the central portion of the conductive layer CDL in plan view. Note that the reflective layer RL may overlap the conductive layer CDL to be off-center in plan view. The area of the conductive layer CDL where the reflective layer RL does not overlap in plan view may be referred to as a contact surface (or contact area) CS. The contact surface CS is disposed over the entire circumference (or the entire periphery) of the conductive layer CDL when viewed in plan view. Note that the contact surface CS, when viewed in plan view, may not be disposed over the entire circumference (or the entire periphery) of the conductive layer CDL. For example, the contact surface CS is disposed in a ring manner when viewed in plan view. In the example shown in  FIG.  2   , the reflective layer RL overlaps the conductive layer CDL when viewed in plan view and is surrounded by the contact surface CS. In other words, the reflective layer RL is disposed on an inner side of the contact surface CS when viewed in plan view. The transparent electrode TE is located above the reflective layer RL and the conductive layer CDL, and overlap the reflective layer RL and conductive layer CDL. In the example shown in  FIG.  2   , the transparent electrode TE is formed into a rectangular shape (oblong or quadrangular) in plan view. Note that the transparent electrode TE may be formed into a shape other than rectangular (oblong or quadrangular) in plan view. The transparent electrode TE is formed into a rectangular shape whose length along the second direction Y is greater than that along the first direction X in plan view. The size (or area) of the transparent electrode TE is greater than the size (or area) of the reflective layer RL in plan view. The size (or area) of the transparent electrode TE may be less than or equal to the size (or area) of the conductive layer CDL in plan view. The transparent electrode TE covers the reflective layer RL and the conductive layer CDL. The transparent electrode TE is in contact with, for example, the conductive layer CDL at the contact surface CS and completely covers the reflective layer RL. 
     The lower electrode E 11  includes a transparent electrode TEl, a reflective layer (or reflective electrode) RL 1  and a conductive layer (or conductive electrode) CDL 1 . In the example shown in  FIG.  2   , the conductive layer CDL 1  is formed into a rectangular shape (oblong or quadrangular) in plan view. Note that the conductive layer CDL 1  may be formed into a shape other than a rectangular shape (oblong or quadrangular) in plan view. The conductive layer CDL 1  is formed into a rectangular shape whose length along the second direction Y is greater than that of the first direction X in plan view. The reflective layer RL 1  is located above the conductive layer CDL 1  and overlaps the conductive layer CDLl. In the example shown in  FIG.  2   , the reflective layer RL 1  is formed into a rectangular shape (oblong or quadrangular shape) in plan view. Note that the reflective layer RL 1  may be formed into a shape other than a rectangular shape (oblong or quadrangular) in plan view. The reflective layer RL 1  is formed into a rectangular shape whose length along the second direction Y is greater than that along the first direction X in plan view. The size (or area) of the reflective layer RL 1  is less than the size (or area) of the conductive layer CDL 1  in plan view. In the example shown in  FIG.  2   , the reflective layer RL 1  overlaps the central portion of the conductive layer CDL 1  in plan view. Note that the reflective layer RL 1  may overlap the conductive layer CDL 1  to be off-center in plan view. In the example shown in  FIG.  2   , the reflective layer RL 1 , when viewed in plan view, overlaps the conductive layer CDL 1  and is surrounded by the contact surface CS 1 . In other words, the reflective layer RL 1  is disposed on an inner side of the contact surface CS 1  when viewed in plan view. The transparent electrode TE 1  is located above the reflective layer RL 1  and the conductive layer CDL 1  and overlaps the reflective layer RL 1  and the conductive layer CDLl. In the example shown in  FIG.  2   , the transparent electrode TEl is formed into a rectangular shape (oblong or quadrangular) in plan view. Note that the transparent electrode TEl may be formed into a shape other than a rectangular shape (oblong or quadrangular shape) in plan view. The transparent electrode TEl is formed into a rectangular shape whose length along the second direction Y is greater than the length along the first direction X in plan view. The size (or area) of the transparent electrode TEl is larger than that of the reflection layer RL 1  in plan view. Note that the size (or area) of the transparent electrode TEl may be less than or equal to the size (or area) of the conductive layer CDL 1  in plan view. The transparent electrode TE 1  covers the reflective layer RL 1  and the conductive layer CDL 1 . The transparent electrode TEl is in contact with, for example, the conductive layer CDL 1  at the contact surface CS 1  and completely covers the reflective layer RL 1 . 
     The lower electrode E 12  includes a transparent electrode TE 2 , a reflective layer (or reflective electrode) RL 2  and a conductive layer (or conductive electrode) CDL 2 . In the example shown in  FIG.  2   , the conductive layer CDL 2  is formed into a rectangular shape (oblong or quadrangular) in plan view. The conductive layer CDL 2  may be formed into a shape other than a rectangular shape (oblong or quadrangular shape) in plan view. The conductive layer CDL 2  is formed into a rectangular shape whose length along the second direction Y is greater than the length along the first direction X in plan view. The reflective layer RL 2  is located above the conductive layer CDL 2  and overlaps the conductive layer CDL 2 . In the example shown in  FIG.  2   , the reflective layer RL 2  is formed into a rectangular shape (oblong or quadrangular shape) in plan view. The reflective layer RL 2  may be formed into a shape other than a rectangular shape (oblong or quadrangular) in plan view. The reflective layer RL 2  is formed into a rectangular shape whose length along the second direction Y is greater than the length along the first direction X in plan view. The size (or area) of the reflective layer RL 2  is less than the size (or area) of the conductive layer CDL 2  in plan view. In the example shown in  FIG.  2   , the reflective layer RL 2  overlaps the central portion of the conductive layer CDL 2  in plan view. The reflective layer RL 2  may overlap the conductive layer CDL 2  to be off-center in plan view. In the example shown in  FIG.  2   , the reflective layer RL 2 , when viewed in plan view, overlaps the conductive layer CDL 2  and is surrounded by the contact surface CS 2 . In other words, the reflective layer RL 2  is disposed on an inner side of the contact surface CS 2  when viewed in plan view. The transparent electrode TE 2  is located above the reflective layer RL 2  and the conductive layer CDL 2  and overlaps the reflective layer RL 2  and the conductive layer CDL 2 . In the example shown in  FIG.  2   , transparent electrode TE 2  is formed into a rectangular shape (oblong or quadrangular) in plan view. The transparent electrode TE 2  may be formed into a shape other than a rectangular shape (oblong or quadrangular shape) in plan view. The transparent electrode TE 2  is formed in a rectangular shape whose length along the second direction Y is greater than the length along the first direction X in plan view. The size (or area) of the transparent electrode TE 2  is greater than that of the reflection layer RL 2  in plan view. The size (or area) of the transparent electrode TE 2  may be smaller than or equal to the size (or area) of the conductive layer CDL 2  in plan view. The transparent electrode TE 2  covers the reflective layer RL 2  and the conductive layer CDL 2 . The transparent electrode TE 2  is in contact with, for example, the conductive layer CDL 2  at contact surface CS 2  and completely covers the reflective layer RL 2 . 
     The lower electrode E 13  includes a transparent electrode TE 3 , a reflective layer (or reflective electrode) RL  3  and a conductive layer (or conductive electrode) CDL 3 . In the example shown in  FIG.  2   , the conductive layer CDL 3  is formed into a rectangular shape (oblong or quadrangular) in plan view. Note that the conductive layer CDL 3  may be formed into a shape other than rectangular (oblong or quadrangular) in plan view. The conductive layer CDL 3  is formed into a rectangular shape whose length along the second direction Y is greater than the length along the first direction X in plan view. The reflective layer RL 3  is located above the conductive layer CDL 3  and overlaps the conductive layer CDL 3 . In the example shown in  FIG.  2   , the reflective layer RL 3  is formed into a rectangular shape (oblong or quadrangular) in plan view. Note that the reflective layer RL 3  may be formed into a shape other than a rectangular shape (oblong or quadrangular) in plan view. The reflective layer RL 3  is formed into a rectangular shape whose length along the second direction Y is greater than the length in the first direction X in plan view. The size (or area) of the reflective layer RL 3  is less than the size (or area) of the conductive layer CDL 3  in plan view. In the example shown in  FIG.  2   , the reflective layer RL 3  overlaps the central portion of the conductive layer CDL 3  in plan view. Note that the reflective layer RL 3  may overlap the conductive layer CDL 3  to be off-center in plan view. In the example shown in  FIG.  2   , the reflective layer RL 3 , when viewed in plan view, overlaps the conductive layer CDL 3  and is surrounded by the contact surface CS 3 . In other words, the reflective layer RL 3  is disposed on an inner side of the contact surface CS 3  when viewed in plan view. The transparent electrode TE 3  is located above the reflective layer RL 3  and the conductive layer CDL 3  and overlaps the reflective layer RL 3  and the conductive layer CDL 3 . In the example shown in  FIG.  2   , the transparent electrode TE 3  is formed into a rectangular shape (oblong or quadrangular) in plan view. Note that the transparent electrode TE 3  may be formed into a shape other than a rectangular shape (oblong or quadrangular shape) in plan view. The transparent electrode TE 3  is formed into a rectangular shape whose length along the second direction Y is greater than the length along the first direction X. The size (or area) of the transparent electrode TE 3  is greater than that of the reflection layer RL 3  in plan view. Note that the size (or area) of the transparent electrode TE 3  may be less than or equal to the size (or area) of the conductive layer CDL 3  in plan view. The transparent electrode TE 3  covers the reflective layer RL 3  and the conductive layer CDL 3 . The transparent electrode TE 3  is in contact with, for example, the conductive layer CDL 3  at the contact surface CS 3  and completely covers the reflective layer RL 3 . 
     The insulating layer  12  is formed into a grid pattern in plan view. The insulating layer  12  is formed to compartmentalize display elements or sub-pixels and may be referred to as banks, ribs, partition walls or the like. In the example shown in  FIG.  2   , the insulating layer  12  includes insulating layers (banks)  1211 ,  1212 ,  1213 ,  1214 ,  1221  and  1222 . The insulating layers  1211 ,  1212 ,  1213  and  1214  extend along the second direction Y. The insulating layers  1211  to  1214  are arranged to be spaced apart from each other along the first direction X. The insulating layers  1211 ,  1212 ,  1213  and  1214  are aligned in the order listed toward the tip end of the arrow along the first direction X. The insulating layers  1221  and  1222  extend along the first direction X. The insulating layers  1221  and  1222  are arranged to be spaced apart from each other along the second direction Y. For example, the insulating layers  1221  and  1222  are aligned in the order listed toward the tip end of the arrow along the second direction Y. The insulating layers  1211  to  1214  and the insulating layers  1221  and  1222  intersect each other, respectively. The insulating layer  12  comprises an opening OP overlapping the lower electrode El. In the example shown in  FIG.  2   , when viewed in plan view, the size (or area) of the opening OP is less than or equal to the size (or area) of the conductive layer CDL and is greater than or equal to the size (or area) of the reflective layer RL. Note that the size (or area) of the opening OP may be greater than the size (or area) of the conductive layer CDL. Further, the size (or area) of the opening OP may be less than the size (or area) of the reflective layer RL. In the example shown in  FIG.  2   , the insulating layer  12  includes an opening OP 1  overlapping the lower electrode E 11 , an opening OP 2  overlapping the lower electrode E 12  and an opening OP 3  overlapping the lower electrode E 13 . When viewed in plan view, the size (or area) of the opening OP 1  is less than or equal to the size (or area) of the conductive layer CDL 1  and is greater than or equal to the size (or area) of the reflective layer RL 1 . The size (or area) of the opening OP 1  may be greater than the size (or area) of the conductive layer CDL 1 . The size (or area) of the opening OP 1  may be less than the size (or area) of the reflective layer RL 1 . The opening OP 1  corresponds to the area surrounded by the insulating layers  1211  and  1212  and the insulating layers  1221  and  1222  In other words, the central portion of the lower electrode E 11 , overlaps the opening OP 1 , is exposed from the insulating layer  12 . The corners of the opening OP 1  are rounded (or to have R (radius)). The corners of the opening OP 1  may not be rounded or may intersect at right angles. When viewed in plan view, the size (or area) of the opening OP 2  is less than or equal to the size (or area) of the conductive layer CDL 2  and is larger than or equal to the size (or area) of the reflective layer RL 2 . Note that the size (or area) of the opening OP 2  may be larger than the size (or area) of the conductive layer CDL 2 . The size (or area) of the opening OP 2  may be less than the size (or area) of the reflective layer RL 2 . The opening OP 2  corresponds to the area surrounded by the insulating layers  1212  and  1213  and the insulating layers  1221  and  1222 . That is, the central portion of the lower electrode E 12 , which overlaps the opening OP 2 , is exposed from the insulating layer  12 . The corners of the opening OP 2  are rounded (or to have R (radius)). Note that the corners of the opening OP 2  may not be rounded or may intersect at right angles. When viewed in plan view, the size (or area) of the opening OP 3  is less than or equal to the size (or area) of the conductive layer CDL 3  and is larger than or equal to the size (or area) of the reflective layer RL 3 . Note that the size (or area) of the opening OP 3  may be larger than the size (or area) of the conductive layer CDL 3 . The size (or area) of the opening OP 3  may be less than the size (or area) of the reflective layer RL 3 . The opening OP 3  corresponds to the area surrounded by the insulating layers  1213  and  1214  and the insulating layers  1221  and  1222 . That is, the central portion of the lower electrode E 13 , which overlaps the opening OP 3 , is exposed from the insulating layer  12 . The corners of the opening OP 3  are rounded (or to have R (radius)). The corners of the opening OP 3  may not be rounded but may intersect at right angles. 
     In the example shown in  FIG.  2   , the insulating layer  12  covers the peripheral portion of each of the lower electrode E 11  to E 13 . The insulating layer  1221  overlaps an end portion of the lower electrode E 11 , on an opposite side to the tip of the arrow in the second direction Y, an end portion of the lower electrode E 12 , on an opposite side to the tip of the arrow in the second direction Y, and an end portion of the lower electrode E 13 , on an opposite side to the tip of the arrow in the second direction Y. The insulating layer  1222  overlaps an end portion of the lower electrode E 11 , on a side of the tip of the arrow in the second direction Y, an end portion of the lower electrode E 12 , on a side of the tip of the arrow in the second direction Y, and an end portion of the lower electrode E 13 , on a side of the tip of the arrow in the second direction Y. The insulating layer  1211  overlaps an end portion of the lower electrode E 11 , on an opposite side to the tip of the arrow along the first direction X. The insulating layer  1212  overlaps an end portion of the lower electrode E 11  on the tip of the arrow in the second direction Y, and an end portion of the lower electrode E 12  on an opposite side to the tip of the arrow in the first direction X. The insulating layer  1213  overlaps an end portion of the lower electrode E 12  on the tip of the arrow in the direction X, and overlaps an end portion of the lower electrode E 13  on an opposite side to the tip of the arrow in the first direction X. The insulating layer  1214  overlaps an end portion of the lower electrode E 13  on the side of tip of the arrow in the first direction X. 
     Here, the outline of the sub-pixel SP is equivalent to the outline of the lower electrode E 1 , for example. In other words, the sub-pixel SP 1 , the sub-pixel SP 2  and the sub-pixel SP 3 , which constitute one pixel PX, are formed into a rectangular shape (or quadrangular). The sub-pixel SP 1  is formed into an approximately rectangular shape extending along the second direction Y, the sub-pixel SP 2  is formed into an approximately rectangular shape extending in the second direction Y, and the sub-pixel SP 3  is formed into an approximately rectangular shape extending in the second direction Y. The sub-pixels SP 1 , SP 2  and SP 3  are aligned along the first direction X. The sub-pixels SP aligned adjacent to each other along the first direction X emit colors different from each other. Note that the emission colors of the adjacent sub-pixels SP may be the same as each other. The width of the sub-pixel SP 1  along the first direction X, the width of the sub-pixel SP 2  along in the first direction X, and the width of the sub-pixel SP 3  along the first direction X are the same as each other. Note that the width of the sub-pixel SP 1  along the first direction X, the width of the sub-pixel SP 2  along the first direction X, the width of the sub-pixel SP 3  along the first direction X may be different from each other. The width of the sub-pixel SP 1  along the second direction Y, the width of the sub-pixel SP 2  along the second direction Y, and the width of the sub-pixel SP 3  along the second direction Y are the same as each other. Note that the width of the sub-pixel SP 1  along the second direction Y, the width of the sub-pixel SP 2  along in the second direction Y, and the width of the sub-pixel SP 3  along the second direction Y may be different from each other. The area of the sub-pixel SP 1 , the area of the sub-pixel SP 2  and the area of the sub-pixel SP 3   3  are the same as each other. Note that the area of the sub-pixel SP 1 , the area of the sub-pixel SP 2  and the area of the sub-pixel SP 3  may be different from each other. The outline of the sub-pixels may be defined by the outline of the light-emitting area of the display element. The expressions “same”, “identical” and “equivalent” may cover situations where not only the physical quantity, material, or configuration (structure) of a plurality of subject objects, spaces, or areas and the like are exactly the same as each other, but also slightly different to the extent that they may be regarded as being substantially the same as each other. 
       FIG.  3    is a cross-sectional view showing a configuration example of the display element  20  according to this embodiment. Note that  FIG.  3    illustrates only the configuration necessary for explanation. 
     The display device DSP includes a base  10 , an insulating layer  11 , an insulating layer  12  ( 1212  and  1213 ), a display element  20  and an organic layer OR. 
     The display element  20  includes a lower electrode El (E 12 ), an organic layer OR (OR 2 ) and an upper electrode E 2 . The lower electrode E 1  (E 12 ) includes a conductive layer CDL (CDL 2 ), a reflective layer RL (RL 2 ) and a transparent electrode TE (TE 2 ). Note that the lower electrode E 1  may include a conductive layer CDL and a reflective layer RL. Further, the lower electrode E 1  may as well include a reflective layer RL. The organic layers OR (OR 1 , OR 2  and OR 3 ) includes a functional layer F 1 , a light-emitting layer EL (EL 1 , EL 2  and EL 3 ) and a functional layer F 2 . The functional layers F 1  and F 2  include, for example, a hole injection layer, a hole transport layer, a hole block layer, an electron injection layer, an electron transport layer and an electron block layer. The functional layers F 1  and F 2  may not include at least one of the hole injection layer, hole transport layer, hole block layer, electron injection layer, electron transport layer and electron block layer. The functional layers F 1  and F 2  may as well include a layer(s) other than the hole injection layer, hole transport layer, hole block layer, electron injection layer, electron transport layer and electron block layer. Each of the functional layers F 1  and F 2  is not limited to a single layer, but may as well be a stacked body in which multiple functional layers are stacked. Further, at least one of the functional layers F 1  and F 2  may be omitted. 
     The insulating layer  11  is disposed on the base  10 . The insulating layer  11  is equivalent to the base layer of the display element  20  and is, for example, an organic insulating layer. The pixel switch  2  and the like, of the pixel circuit  1  shown in  FIG.  1    are disposed on the base  10  and are covered by an insulating layer, for example, the insulating layer  11 , which is omitted from the figure. The insulating layer  11  may be formed from a single layer or multiple layers. Further, some other layer(s) may be disposed between the base  10  and the insulating layer  11 . 
     The lower electrode E 1  is disposed on the insulating layer  11 . In the example shown in  FIG.  3   , the lower electrode E 1  includes a lower electrode E 12 . The lower electrode E 12  is disposed above the insulating layer  11 . Although not shown in the figure, the lower electrode E 1  is electrically connected to the switching element via a contact hole formed in the insulating layer  11 . For example, although not shown, the lower electrode E 12  is electrically connected to the switching element via the contact hole formed in the insulating layer  11 . Note that between the lower electrode E 1  and the insulating layer  11 , some other layer(s) may be disposed. For example, between the lower electrode E 12  and the insulating layer  11 , some other layer(s) may be disposed. 
     In the example shown in  FIG.  3   , the lower electrode E 1  comprises a conductive layer CDL, a reflective layer RL and a transparent electrode TE, which are stacked in the listed order. Not that the lower electrode E 1  may be constituted by a conductive layer CDL and a reflective layer RL stacked in the listed order. The lower electrode E 1  may as well be constituted by the reflective layer RL. The conductive layer CDL is disposed on the insulating layer  11 . The conductive layer CDL is made of a metal material which has good electrical contact with the transparent electrode TE (and the switching element), for example, titanium or a metal material containing titanium (a titanium alloy). Note that as long as the conductive layer CDL has good electrical contact with the transparent electrode TE, it may be formed of a metal material other than titanium or a metal material containing titanium, that is, for example, TiN, Ta, TaN, Mo, W, Cr or the like. The conductive layer CDL is electrically connected to the switching element via the contact hole formed in the insulating layer  11 . For example, although not shown in the figure, the conductive layer CDL is electrically connected to the switching element via the contact hole formed in the insulating layer  11 . The conductive layer CDL includes a conductive layer CDL 2 . The reflective layer RL is disposed on the conductive layer CDL. The reflective layer RL is formed of a metal material that has high reflectivity and can be micro-processed by dry etching, and the like, for example, aluminum (Al), Al—Ni, Al—Ni—La, or a metal material containing aluminum (Al alloy). Note that the reflective layer RL may be, as long as it has high reflectivity and can be micromachined by dry etching or the like, made of any metal material other than aluminum (Al), Al—Ni, Al—Ni—La or a metal material containing aluminum. Lanthanum (La) has the effect of suppressing hillocks that may occur on the surface of the reflective layer RL. Therefore, when heat resistance is required, La may be added to the reflective layer RL. The reflective layer RL includes a reflective layer RL 2 . The transparent electrode TE is disposed on the reflective layer RL and the conductive layer CDL, to cover the reflective layer RL and the conductive layer CDL. For example, the transparent electrode TE covers at least the reflection layer RL so as not to expose the reflection layer RL. The transparent electrode TE is formed from a transparent electrode with a large band gap, for example, indium tin oxide (ITO). The transparent electrode TE includes a transparent electrode TE 2 . 
     For example, the lower electrode E 12  comprises a conductive layer CDL 2 , a reflective layer RL 2  and a transparent electrode TE 2  stacked in the listed order. The cross-section of the lower electrode E 12  has a tapered shape in the X-Z plane. The cross-section of the lower electrode E 12  has a tapered shape in the X-Z plane. The cross-section of the lower electrode E 12  is formed into a trapezoidal shape including, in the X-Z plane, an upper surface (or upper bottom) EU 1  located on the side of the tip of the arrow in the third direction Z, a lower surface (or lower bottom) ED 1  located on the opposite side to the upper bottom EU 1  in the third direction Z, an end portion (a side portion, side portion or inclined surface) ES 11  located on the opposite side of the tip of the arrow in the first direction X, and an end portion (a side portion, side surface or inclined surface) ES 12  located on the opposite side to the end portion (a side portion, side portion or inclined surface) ES 11  in the first direction X. The side portion ES 11  is formed into an inclined surface from the tip side of the arrow in the first direction X (inner side) to the side opposite the tip of the arrow in the first direction X (outer side), that is, from the upper side towards the lower side in the third direction. In other words, the side ES 11  is an inclined surface that expands to the opposite side to the tip of the arrow in the first direction X, towards the lower side along the third direction Z. The side ES 12  is formed into an inclined surface from an opposite side (inner side) to the tip side (outer side) of the arrow in the first direction X, that is, from the upper side to the lower side in the third direction. In other words, the side portion ES 12  is an inclined surface which expands to the tip side of the arrow in the first direction X towards the lower side in the third direction Z. The side portion ES 11  is connected to the end portion of the lower bottom RD 1 , located on an opposite side to the tip of the arrow in the first direction X, and the end portion of the upper bottom EU 1 , located on an opposite side to the tip of the arrow in the first direction X. The side portion ES 12  is connected to an end portion of the upper bottom EU 1 , opposite to the end to which the side portion ES 11  is connected, and an end portion of the lower bottom ED 1 , opposite to the end to which the side portion ES 11  is connected. The upper bottom EU 1  is covered by an organic layer OR 2 . The side portion ES 11  is covered by an insulating layer  12 , for example, the insulating layer  1212 . The side portion ES 12  is covered by an insulating layer  12 , for example, the insulating layer  1213 . The width of the upper bottom EU 1  in the first direction X is greater than or equal to the width of the opening OP 2  in the first direction X. Note that the width of the upper bottom EU 1  in the first direction X may be less than the width of the opening OP 2  in the first direction X. As the process of forming the lower electrode E 12 , two processes of photoetching may be required for forming the conductive layer CDL 2  and the reflective layer RL 2  and the transparent electrode TE 2 , respectively. For example, in the process of formation of the lower electrode E 12 , the conductive layer CDL 2  and the reflective layer RL 2  are etched at one time by a forward taper manner. 
     The conductive layer CDL 2  is disposed on the insulating layer  11 . The conductive layer CDL 2  is electrically connected to the switching element via the contact hole formed in the insulating layer  11 . For example, although not shown in the figure, the conductive layer CDL 2  is electrically connected to the switching element via the contact hole formed in the insulating layer  11 . The cross-section of the conductive layer CDL 2  has a tapered shape in the X-Z plane. The cross-section of the conductive layer CDL 2  is formed into a trapezoidal shape including, in the Z-Y plane, an upper surface (or upper bottom) CDU 1  located on the side of the tip of the arrow in the third direction Z, a lower surface (or lower bottom) CDD 1  located on the opposite side to the upper bottom CDU 1  in the third direction Z, an end portion (a side portion, side portion or inclined surface) CDS 1  located on the opposite side of the tip of the arrow in the first direction X, and an end portion (a side portion, side surface or inclined surface) CDS 2  located on the opposite side to the end portion (side portion, side portion or inclined surface) CDS 1  in the first direction X. The side portion CDS 1  is formed into an inclined surface from the tip side of the arrow in the first direction X (inner side) to the side opposite the tip of the arrow in the first direction X (outer side), that is, from the upper side towards the lower side in the third direction. In other words, the side CDS 1  is an inclined surface that expands to the opposite side to the tip of the arrow in the first direction X, towards the lower side along the third direction Z. The side portion CDS 2  is formed into an inclined surface from an opposite side (inner side) to the tip side of the arrow in the first direction X to the tip side (outer side) of the arrow in the first direction X, that is, from the upper side to the lower side in the third direction. In other words, the side portion CDS 2  is an inclined surface which expands to the tip side of the arrow in the first direction X towards the lower side in the third direction Z. The end portions CDS 1  and CDS 2  are equivalent to a contact surface CS 2 . The side portion CDS 1  is connected to the end portion of the upper bottom CDU 1 , located on an opposite side to the tip of the arrow in the first direction X, and the end portion of the lower bottom CDD 1 , located on an opposite side to the tip of the arrow in the first direction X. The side portion ES 12  is connected to an end portion of the upper bottom CDU 1 , opposite to the end to which the side portion CDS 1  is connected, and an end portion of the lower bottom CDD 1 , opposite to the end to which the side portion CDS 1  is connected. The lower bottom CDD 1  is located on the insulating layer  11 . The side portions CDS 1  and CDS 2  are covered by the transparent electrode TE 2 . A thickness CDT 1  of the conductive layer CDL 2  is greater than or equal to a thickness RT 1  of the reflective layer RL 2 . For example, the thickness CDT 1  of the conductive layer CDL 2  is 100 nm (nanometer) or less. 
     The reflective layer RL 2  is disposed on the conductive layer CDL 2 . The cross-section of the reflective layer RL 2  has a tapered shape in the X-Z plane. The cross-section of the reflective layer RL 2  is formed into a trapezoidal shape including, in the X-Z plane, an upper surface (or upper bottom) RU 1  located on the tip side of the arrow in the third direction Z, a lower surface (or lower bottom) RD 1  located on the opposite side to the upper bottom RU 1  in the third direction Z, an end portion (a side portion, side surface or inclined surface) RS 1  located on the opposite side of the tip of the arrow in the first direction X, and an end portion (a side portion, side surface or inclined surface) RS 2  located on the opposite side to the inclined surface RS 1  in the first direction X. The end portion RS 1  is formed into an inclined surface from the tip side (inner side) of the arrow in the first direction X to an opposite side (outer side) to the tip side of the arrow in the first direction X, that is, from the upper side to the lower side in the third direction. In other words, the side portion RS 1  is an inclined surface which expands to an opposite side (outer side) to the tip of the arrow in the first direction X towards the lower side in the third direction Z. For example, the side portion RS 1  is formed into an inclined surface that is continuous to the side portion CDS 1  in the X-Y plane. In other words, the side portion CDS 1  is located on an outer side further from the side portion RS 1 , that is, for example, on an opposite side to the tip of the arrow in the first direction X. For example, the side portion RS 1  and the side portion CDS 1  are formed at one time in forward tapering etching manner in the X-Y plane. The side portion RS 2  is formed into an inclined surface from an opposite side (inner side) to the tip of the arrow in the first direction X towards the tip side (outer side) of the arrow in the first direction X from the upper side to the lower side in the third direction Z. In other words, the side portion RS 2  is formed into an inclined surface which expands toward the tip side (outer side) of the arrow in the first direction X from the opposite side (inner side) to the tip of the arrow in the first direction X. In other words, the side portion RS 2  is an inclined surface which expands to the tip side of the arrow in the first direction X toward the lower side in the third direction  3 . For example, the side portion RS 2  is formed into an inclined surface that is continuous to the side portion CDS 2  in the X-Y plane. In other words, the side portion CDS 2  is located on a further outer side of the side portion RS 2 , that is, for example, on the opposite side to the tip of the arrow in the first direction X. For example, the side portion RS 2  and the side portion CDS 2  are formed at once by forward taper etching in the X-Y plane. The side portion RS 1  is connected to the end portion of the upper bottom RU 1 , which is located on an opposite side to the tip of the arrow in the first direction X and the end portion of the lower bottom RD 1 , which is located on an opposite side to the tip of the arrow in the first direction X. The side portion RS 2  is connected to the end portion of the upper bottom RU 1 , on an opposite side to the end to which the side portion RS 1  is connected, and the end portion of the lower bottom RD 1 , which is located on an opposite side to the end to which the side portion RS 1  is connected. The lower bottom RD 1  is located on the upper bottom CDU 1  of the conductive layer CDL 2 . The width of the lower bottom RD 1  along the first direction X is the same as the width of the upper bottom CDU 1  of the conductive layer CDL 2  along the first direction X. Note that the width of the lower bottom RD 1  along the first direction X may be less than the width of the upper bottom CDU 1  of the conductive layer CDL 2  along the first direction X. The width of the upper bottom RU 1  along the first direction X is greater than or equal to, for example, the width of the opening OP 2  along the first direction X. The width of the upper bottom RU 1  along the first direction X may be, for example, less than the width of the opening OP 2  along the first direction X. The upper bottom RU 1 , the side portion RS 1  and the side portion RS 2  are covered by the transparent electrode TE 2 . For example, in the case where the reflective layer RL 2  is Al or an Al alloy and the transparent electrode TE is ITO, it is difficult to electrically connect the transparent electrode TE to the reflective layer RL 2  because Alx is formed at the interface of the reflective layer RL 2 . The thickness RT 1  of the reflective layer RL 2  is less than or equal to the thickness CDT 1  of the conductive layer CDL 2 . Further, the thickness RT 1  of the reflective layer RL 2  is greater than the thickness TT 1  of the transparent electrode TE 2 . For example, the thickness RT 1  of the reflective layer RL 2  is 50 to 100 nm. For example, the thickness TT 2  of the transparent electrode TE 2  is 5 to 10 nm. 
     In the patterning process after the formation of the lower electrode E 1 , when the lower electrode E 1  of aluminum and ITO is exposed to an atmosphere of alkaline liquid (for example, stripping solution, developing solution or the like) in a stripping process or the like, a mutual corrosion reaction (galvanic corrosion reaction) between aluminum and ITO may occur. When the galvanic corrosion reaction occurs, degradation of pixels PX, rise in applied voltage and degradation of the lower electrode E 1  over time may occur. In the lower electrode E 1  of the display element  20  shown in  FIG.  3   , the reflection layer RL is covered by the transparent electrode TE, and thus the reflective layer RL and the transparent electrode TE are prevented from being exposed to an alkaline liquid atmosphere at the same time. In this manner, the occurrence of galvanic corrosion reactions can be prevented in the display element  20  shown in  FIG.  3   . 
     In the example shown in  FIG.  3   , the insulating layer  12  is located on the insulating layer  11  and the lower electrode E 1 . The insulating layer  12  may be formed from a single layer or in multiple layers. The insulating layer  12  includes the insulating layers  1212  and  1213 . For example, the insulating layer  1212  covers the insulating layer  11  and the side portion ES 11  of the lower electrode E 12 . The insulating layer  1212  covers the transparent electrode TE 2  which covers the side portion RS 1  of the reflective layer RL 2  and the side portion CDS 1  of the conductive layer CDL 2 . The insulating layer  1213  covers the insulating layer  11  and the end portion ES 12  of the lower electrode E 12 . The insulating layer  1213  covers the transparent layer TE 2  which covers the side portion RS 2  of the reflective layer RL 2  and the side portion CDS 2  of the conductive layer CDL 2 . 
     The organic layer OR covers the lower electrode E 1  and the insulating layer  12 . The organic layer OR is constituted by a functional layer F 1 , a light-emitting layer EL and a functional layer F 2  stacked in the order listed. In the example shown in  FIG.  3   , the organic layer OR includes organic layers OR 1 , OR 2  and OR 3 . For example, the organic layer OR 2  covers the lower electrode E 12 , the insulating layer  1212  and the insulating layer  1213 . The organic layer OR 2  comprises a functional layer F 1 , a light-emitting layer EL 2  and a functional layer F 2 , which are stacked in the order listed. The organic layer OR 1  is located on the opposite side to the organic layer OR 2  with respect to the tip of the arrow in the first direction X. The organic layer OR 1  covers the insulating layer  1212 . The organic layer OR 1  is constituted by a functional layer F 1 , a light-emitting layer EL 1  and a functional layer F 2 , which are stacked in the order listed. The organic layer OR 3  is located on the tip side of the organic layer OR 2  with respect to the arrow in the first direction X. The organic layer OR 3  covers the insulating layer  1213 . The organic layer OR 3  comprises a functional layer F 1 , a light-emitting layer EL 3  and a functional layer F 2 , which are stacked in the order listed. The functional layer F 1  covers the insulating layer  1212 , the transparent electrode TE 2  and insulating layer  1213 . The light-emitting layers EL 1 , EL 2  and EL 3  are arranged in the order listed so as to be spaced apart from each other along the first direction X. The light-emitting layer EL 2  is disposed to be spaced apart on the tip side of the light emitting layer EL 1  with respect to the arrow in the first direction X. The light-emitting layer EL 3  is disposed to be spaced apart on the tip side of the light emitting layer EL 2  with respect to the arrow in the first direction X. The light-emitting layers EL 1 , EL 2  and EL 3  are disposed on the functional layer F 1 . The light-emitting layers EL 1  to EL 3  are light-emitting layers of different colors, for example. The light-emitting layer EL 1  is, for example, a red light-emitting layer, the light-emitting layer EL 2  is, for example, a green light-emitting layer, and the light-emitting layer EL 3  is, for example, a blue light-emitting layer. Note that the light-emitting layer EL 1  may be, for example, a green or blue light-emitting layer. The light-emitting layer EL 2  may be, for example, a red or blue light-emitting layer. The light-emitting layer EL 3  may be, for example, a red or green light-emitting layer. The light-emitting layers EL 1  through EL 3  may be light-emitting layers of the same color, for example, white. The functional layer F 2  covers the light-emitting layers EL 1 , EL 2  and EL 3 . 
     The upper electrode E 2  is disposed on the organic layer OR. In the example shown in  FIG.  3   , the upper electrode E 2  is disposed on the organic layer OR 1 , organic layer OR 2  and organic layer OR 3 . For example, the upper electrode E 2  is disposed on the functional layer F 2 . The upper electrode E 2  is made of MgAg or a metal material containing MgAg. Note that the upper electrode E 2  may be made of, for example, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). Further, the upper electrode E 2  is an electrode commonly disposed for a plurality of sub-pixels SP or a plurality of display elements  20 , and may be referred to as a common electrode, a counter electrode, a negative electrode or a cathode. Note that the upper electrode E 2  may be covered by a transparent protective layer (including at least one of an inorganic insulating layer and an organic insulating layer). The upper electrode E 2  may be constituted by a single layer or as a stacked layer body. Note that the upper electrode E 2  may be electrically connected to the feeding line FL located in the display area DA shown in  FIG.  1   . 
     In the example shown in  FIG.  3   , the display device DSP comprises a reflective layer (for example, Al or Al alloy) RL 2  and a transparent electrode (for example, ITO) TE 2  disposed on top of the reflective layer, and with this structure, it is possible to optimize the work function for hole injection into the organic layer OR 2  and to prevent the creation of unevenness due to hillocks on the surface of the reflective layer RL 2 . 
       FIG.  4    is a cross-sectional view showing a configuration example of the display element  20   c  according to a comparative example. In the display device DSP shown in  FIG.  4   , parts that are identical to those of the display device DSP shown in  FIG.  3    are designated by the same reference symbols, and the detailed explanations thereof will be omitted. The parts different from those described above will be mainly explained. 
     The display device DSP of the comparative example includes a base  10 , an insulating layer  11 , an insulating layer  12 , a display element  20   c  and an organic layer OR. The display element  20   c  includes a lower electrode Elc, an organic layer OR and an upper electrode E 2 . The lower electrode Elc includes a reflective layer DRL, a conductive layer UCL and a transparent electrode TE. 
     In the example shown in  FIG.  4   , the lower electrode Elc comprises a reflective layer DRL, a conductive layer UCL and a transparent electrode TE, which are stacked in the order listed. The reflective layer DRL is placed on the insulating layer  11 . Between the reflective layer DRL and the insulating layer  11 , some other layer may be disposed. The reflective layer DRL is made of a metal material which has high reflectivity and can be micromachined by dry etching or the like, that is, for example, aluminum (Al), Al—Ni, Al—Ni—La or a metal material containing aluminum (Al alloy). As long as it has high reflectivity and can be micromachined by dry etching, metal materials other than aluminum (Al), Al—Ni, Al—Ni—La or a metal material containing aluminum (Al alloy) may be used for the reflective layer DRL. The reflective layer DRL is electrically connected to the switching device via a contact hole formed in the insulating layer  11 . For example, although not shown in the figure, the reflective layer DRL is electrically connected to the switching element via the contact hole formed in the insulating layer  11 . The conductive layer UCL is disposed on the reflective layer DRL. The conductive layer UCL is formed of a metal material that has good electrical contact with the transparent electrode TE, that is, for example, titanium (Ti) or a metal material containing titanium. Note that as long as it has good electrical contact with the transparent electrode TE, metal materials other than titanium or a titanium-containing metallic material, that is, for example, TiN, Ta, TaN, Mo, W, Cr or the like may be used to form the conductive layer UCL. The transparent electrode TE is disposed on the conductive layer UCL. The transparent electrode TE is formed from a transparent electrode with a large band gap, for example, indium tin oxide (ITO). 
     The cross-section of the lower electrode Elc is, in the X-Z plane, formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. The cross-section of the reflective layer DRL is, in the X-Z plane, formed into a rectangular shape whose length along the first direction X is greater the length along the third direction Z. The cross-section of the conductive layer UCL is, in the X-Z plane, formed into a rectangular shape whose length along the first direction X is greater than the length in the third direction Z. The cross-section of the transparent electrode TE is, in the X-Z plane, formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. 
     Both end portions of the lower electrode E 1   c  along the first direction X are covered by the insulating layer  12 . Both end portions of the reflective layer DRL along the first direction X are covered by the insulating layer  12 . Both end portions of the conductive layer UCL along the first direction X are covered by the insulating layer  12 . Both end portions of the transparent electrode TE along the first direction X are covered by the insulating layer  12 . The width of the reflective layer DRL along the first direction X, the width of the conductive layer UCL along the first direction X and the width of the transparent electrode TE along the first direction X are the same as each other. The width of the reflective layer DRL along the first direction X is, for example, greater than or equal to the width of the opening OP along the first direction X. Note that the width of the reflective layer DRL along the first direction X may be less than the width of the opening OP along the first direction X. The thickness UCT of the conductive layer UCL is, for example, less than the thickness DRT of the reflective layer DRL. 
       FIG.  5    is a schematic diagram showing an example of a brightness-voltage curve. In  FIG.  5   , the horizontal axis indicates voltage (V) and the vertical axis indicates brightness (Cd/m2).  FIG.  5    illustrates a brightness-voltage curve BRL 1  corresponding to the display device DSP of the embodiment shown in  FIG.  3    and a brightness voltage curve CBRL corresponding to the display device DSPc of the comparative example shown in  FIG.  4   . 
     In the example shown in  FIG.  5   , the brightness-voltage curve BRL 1  is about 30% higher than the brightness voltage curve CBRL. In other words, the brightness of the display device DSP of the embodiment shown in  FIG.  3    can be improved by about 30% as compared to the brightness of the display device DSPc of the comparative example shown in  FIG.  4   . The reason why the brightness of the display device DSPc shown in 
       FIG.  3    can be improved as compared to that of the display device DSPc shown in  FIG.  4    is as follows. That is, in the display device DSPc of the comparative example shown in  FIG.  4   , the reflective layer UCL of low reflectivity is disposed on the reflective layer DRL of high reflectivity, whereas in the display device DSP of the embodiment shown in  FIG.  3   , the transparent electrode TE 2  is disposed on the reflective layer RL 2  with high reflectivity. The display device DSP of this embodiment, compared with the display device DSPc of the comparative example, can reduce the drive voltage to achieve the predetermined brightness, and therefore the life of the display element  20  can be improved. Further, the display device DSP according to this embodiment has such a structure that the lower electrode E 1  is configured so that the reflection layer RL 1  is covered by the transparent electrode TE 1 , and therefore damage due to corrosion of the lower electrode E 1  can be reduced. Therefore, the display device DSP of this embodiment can achieve lower drive voltage as well. 
     According to this embodiment, the display device DSP comprises a base  10 , an insulating layer  11 , an insulating layer  12  and a display element  20 . The display element  20  includes a lower electrode E 1 , an organic layer OR and an upper electrode E 2 . The lower electrode E 1  includes a conductive layer CDL, a reflective layer RL and a transparent electrode TE. The organic layer OR includes a functional layer F 1 , a light-emitting layer EL and a functional layer F 2 . The insulating layer  11  is disposed on the base  10 . The lower electrode E 1  is disposed on the insulating layer  11 . The lower electrode E 1  comprises a conductive layer CDL, a reflective layer RL and a transparent electrode TE, which are stacked in the order listed. The conductive layer CDL is disposed on the insulating layer  11 . The reflective layer RL is disposed on the conductive layer CDL. The transparent electrode TE covers the reflective layer RL and the conductive layer CDL. In the lower electrode E 1  of the display device DSP in this embodiment, the reflection layer RL is completely covered by the transparent electrode TE, which prevents the reflective layer RL and the transparent electrode TE from being exposed to an alkaline liquid atmosphere at the same time. Therefore, the display device DSP of this embodiment can prevent the occurrence of galvanic corrosion reactions. That is, the display device DSP can prevent degradation of the pixels PX, rise in applied voltage and degradation over time. The display device DSP can improve the brightness. Therefore, the display device DSP can improve the display quality. 
     Next, modified examples of the first embodiment and embodiments other than the first embodiment will be described with reference to  FIGS.  6 ,  7 ,  8 ,  9 ,  10 ,  11 ,  12 ,  13  and  14   . In the modified examples of the first embodiment and embodiments other than the first embodiment described below, parts identical to those described above are marked with the same reference symbols, and detailed descriptions thereof will be omitted. Parts different from those described above will be mainly explained in detail. Note that advantageous effects similar to those of the embodiments described above can be obtained in the modified examples of the first embodiment and other embodiments than the first embodiment as well. 
     Modified Example 1 
     The display device DSP of Modified Example 1 is different from the display device DSP of the aforementioned embodiment in the configuration of the lower electrode E 1 . 
       FIG.  6    is a cross-sectional view showing a configuration example of a display device  20  according to Modified Example 1.  FIG.  6    shows only the configuration necessary for explanation. In the example shown in  FIG.  6   , the cross-section of the lower electrode E 12  is formed into, in the X-Z plane, an approximately trapezoidal shape including an upper surface EU 1 , a lower surface ED 1 , an end portion ES 11  and an end portion ES 12 . 
     In the example shown in  FIG.  6   , the conductive layer CDL 2  is formed into a plate shape. The cross-section of the conductive layer CDL 2  is formed into, in the X-Z plane, a rectangular shape including an upper surface CDU 1 , a lower surface CDD 1 , an end portion CDS 1  and an end portion CDS 2 . The cross-section of the conductive layer CDL 2  is formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. The conductive layer CDL 2  includes an upper surface CDE 1  of the end portion CDS 1  and an upper surface CDE 2  of the end portion CDS 2 . The upper surface CDE 1  is equivalent to the end portion of the upper surface CDU 1  on a side opposite to the tip of the arrow in the first direction X. The upper surface CDE 2  is equivalent to the end portion of the upper surface CDU 1  on the tip side of the arrow along the first direction X. The upper surfaces CDE 1  and CDE 2  are equivalent to contact surface CS 2 . The upper surfaces CDE 1  and CDE 2  are covered by the transparent electrode TE 2 . In other words, the upper surfaces CDE 1  and CDE 2  are in contact with the transparent electrode TE 2 . On the upper surface CDU 1  except for the upper surface CDE 1  and CDE 2 , the reflective layer RL 2  is provided. That is, the upper surfaces CDE 1  and CDE 2  are each located on an outer side from the reflective layer RL 2 . The upper surface CDE 1  is located on an opposite side to the tip of the arrow in the first direction X, with respect to the reflective layer RL 2 . The upper surface CDE 2  is located on the side of the tip of the arrow in the first direction X with respect to the reflective layer RL 2 . The end portions CDS 1  and CDS 2  each project outwards from the reflective layer RL 2 . The end portion CDS 1  projects to an opposite side to the tip of the arrow along the first direction X with respect to the reflective layer RL 2 . The end portion CDS 2  projects to the tip side of the arrow along the first direction X with respect to the reflective layer RL 2 . The width of the conductive layer CDL 2  along the first direction X is, for example, greater than the width of the opening OP 2  along the first direction X. Note that the width of the conductive layer CDL 2  along the first direction X may be less than or equal to the width of the opening OP 2  along the first direction X. The thickness CDT 2  of the conductive layer CDL 2  is greater than or equal to the thickness TT 1  of the transparent electrode TE 2 . 
     In the example shown in  FIG.  6   , the reflective layer RL 2  is disposed on the upper surface CDU 1  except for the upper surfaces CDE 1  and CDE 2  of the conductive layer CDL 2 . The width of the reflective layer RL 2  along the first direction X is less than the width of the conductive layer CDL 2  along the first direction X. That is, the width of conductive layer CDL 2  along the first direction X is greater than the width of the reflective layer RL 2  along the first direction X. The side portions RS 1  and RS 2  are each disposed on an inner side with respect to the conductive layer CDL 2 . The side portion RS 1  is retracted to the tip of the arrow along the first direction X with respect to the conductive layer CDL 2 . The side portion RS 2  is retracted to the opposite side to the tip of the arrow along the first direction X with respect to the conductive layer CDL 2 . The thickness RT 2  of the reflective layer RL 2  is greater than the thickness CDT 2  of the conductive layer CDL 2 . 
     In the example shown in  FIG.  6   , the insulating layer  1212  covers the side portion ES 11  of the lower electrode E 12 . The insulating layer  1212  covers the transparent electrode TE 2  which covers the side portion RS 1  of the reflective layer RL 2  and the upper surface CDE 1 , and the end portion CDS 1  of the conductive layer CDL 2 . The insulating layer  1213  covers the side portion RS 12  of the lower electrode E 12 . The insulating layer  1213  covers the side portion RS 2  of the reflective layer RL 2  and the upper surface CDE 2 , and the end portion CDS 2  of the conductive layer CDL 2 . 
     In Modified Example 1 having such a configuration as described above, an advantageous effect similar to that of the first embodiment can be exhibited. 
     Additionally, in the display device DSP according to Modified Example 1, the width of the conductive layer CDL along the first direction X is greater than the width of the reflective layer RL along the first direction X, and therefore the contact properties between the conductive layer CDL and the transparent electrode TE can be improved. 
     Modified Example 2 
     The display device DSP of Modified Example 2 is different from the display device DSP of the embodiment described above or that of the modified example thereof in the configuration of the lower electrode E 1 . 
       FIG.  7    is a cross-sectional view of a configuration example of a display device  20  according to Modified Example 2.  FIG.  7    illustrates only the configuration necessary for explanation. 
     In the example shown in  FIG.  7   , the cross-section of the lower electrode E 12  is formed into a rectangular shape, in the X-Z plane, including an upper surface EU 1 , a lower surface ED 1 , a side portion ES 11  and a side portion ES 12 . 
     In the example shown in  FIG.  7   , the conductive layer CDL 2  is formed into a plate shape. The cross-section of the conductive layer CDL 2  is formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. The width of the conductive layer CDL 2  along the first direction X is greater than or equal to the width of, for example, the opening OP 2  along the first direction X. Note that the width of the conductive layer CDL 2  along the first direction X may be less than the width of, for example, the opening OP 2  along the first direction X. 
     In the example shown in  FIG.  7   , the reflective layer RL 2  is directly contactable (or electrically contactable) with the transparent electrode TE and has a corrosion potential equivalent to that of the transparent electrode TE. That is, the reflective layer RL 2  is formed of a material which does not generate a galvanic corrosion reaction, that is, for example, Al—Ni, Al—W alloy, Al—Mo alloy, Al—Ti alloy, Al—Ni—W, Al—Ni—Mo alloy or Al 13  Ni—Ti alloy. 
     In the example shown in  FIG.  7   , the reflective layer RL 2  is disposed on the conductive layer CDL 2 . The reflective layer RL 2  is formed into a plate shape. The cross-section of the reflective layer RL 2  is formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. The width of the reflective layer RL 2  along the first direction X is greater than or equal to the width of, for example, the opening OP 2  along the first direction X. Note that the width of the reflective layer RL 2  along the first direction X may be less than the width of, for example, the opening OP 2  along the first direction X. For example, the width of the reflective layer RL 2  along the first direction X is the same as the width of the conductive layer CDL 2  along the first direction X. Note that the width of the reflective layer RL 2  along the first direction X may be different from the width of the conductive layer CDL 2  along the first direction X. 
     In the example shown in  FIG.  7   , the reflective layer RL 2  is formed of Al alloy, which can decrease the contact resistance between the transparent electrode (for example, ITO) TE 2  and the reflective layer (for example, Al alloy) RL 2 . Therefore the conductive layer CDL 2 , the reflective layer RL 2  and the transparent electrode TE 2 , of the lower electrode E 12 , can be processed together at once by a single photolithography process. 
     In the example shown in  FIG.  7   , the transparent electrode TE 2  is disposed on the reflective layer RL 2 . The transparent electrode TE 2  is formed into a plate shape. The cross-section of the transparent electrode TE 2  is, in the X-Z plane, formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. The width of the transparent electrode TE 2  along the first direction X is larger than or equal to the width of, for example, the opening OP 2  along the first direction X. Note that the width of the transparent electrode TE 2  along the first direction X may be less than the width of, for example, the opening OP 2  along the first direction X. For example, the width of the transparent electrode TE 2  along the first direction X is the same as the width of the reflective layer RL 2  along the first direction X and the width of the conductive layer CDL 2  along the first direction X. Note that the width of the transparent electrode TE 2  along the first direction X may be different from the width of the reflective layer RL 2  along the first direction X and the width of the conductive layer CDL 2  along the first direction X. 
     In the example shown in  FIG.  7   , the insulating layer  1212  covers the side portion ES 11  of the lower electrode E 12 . The insulating layer  1212  covers the end portion of the conductive layer CDL 2 , on an opposite side to the tip of the arrow along the first direction X, the end portion of the reflective layer RL 2 , on an opposite side to the tip of the arrow along the first direction X, and the end portion of the transparent electrode TE 2 , on an opposite side to the tip of the arrow along the first direction X. The insulating layer  1213  covers a side portion ES 12  of the lower electrode E 12 . The insulating layer  1213  covers the end portion of the conductive layer CDL 2 , on the tip end side of the arrow along the first direction X, the end portion of the reflective layer RL 2 , on the tip end side of the arrow along the first direction X, and the end portion of the transparent electrode TE 2 , on the tip end side of the arrow along the first direction X. 
     In Modified Example 2 as well, advantageous effects similar to those of the first embodiment can be obtained. 
     Modified Example 3 
     The display device DSP of Modified Example 3 is different from the display device DSP of each of the embodiment described above and the modified examples in the configuration of the lower electrode E 1 . 
       FIG.  8    is a cross-sectional view showing a configuration example of a display device  20  according to Modified Example 3. 
     In the example shown in  FIG.  8   , the lower electrode E 12  comprises a conductive layer CDL 2  and a reflective layer RL 2 , which are stacked in the order listed. The cross-section of the lower electrode E 12  has a tapered shape in the X-Z plane. The cross-section of the lower electrode E 12  is, in the X-Z plane, formed into a trapezoidal shape including an upper bottom EU 1 , a lower bottom ED 1 , a side portion ES 11  and a side portion ES 12 . The cross-section of the lower electrode E 12  may be, in the X-Z plane, formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. 
     In the example shown in  FIG.  8   , the cross-section of the conductive layer CDL 2  is, in the X-Z plane, formed into a trapezoidal shape including an upper bottom CDU 1 , a lower bottom CDD 1 , a side portion CDS 1  and a side portion CDS 2 . The cross-section of the conductive layer CDL 2  may be, in the X-Z plane, formed into a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. The width of the conductive layer CDL 2  along the first direction X may be greater than or equal to the width of the opening OP 2  along the first direction X, or less than the width of the opening OP 2  along the first direction X. The side portion CDS 1  is covered by the insulating layer  1212 . The side portion CDS 2  is covered with an insulating layer  1213 . 
     In the example shown in  FIG.  8   , the cross-section of the reflective layer RL 2  is, in the X-Z plane, formed into a trapezoidal shape including an upper bottom RU 1 , a lower bottom RD 1 , a side portion RS 1  and a side portion RS 2 . Note that the cross-section of the reflective layer RL 2  may be, in the X-Z plane, formed in a rectangular shape whose length along the first direction X is greater than the length along the third direction Z. The width of the reflective layer RL 2  along the first direction X may be greater than or equal to the width of the opening OP 2  along the first direction X, or less than the width of the opening OP 2  along the first direction X. The side portion RS 1  is covered by the insulating layer  1212 . The side portion RS 2  is covered by the insulating layer  1213 . 
     In the example shown in  FIG.  8   , the insulating layer  1212  covers the side portion ES 11  of the lower electrode E 12 . The insulating layer  1212  covers the side portion RS 1  and the side portion CDS 1 . The insulating layer  1213  covers the side portion ES 12  of the lower electrode E 12 . The insulating layer  1213  covers the side portion RS 2  and the side portion CDS 2 . 
     In the example shown in  FIG.  8   , the functional layer Fl covers the insulating layer  1212 , the reflective layer RL 2  and the insulating layer  1213 . In other words, the functional layer Fl covers the insulating layer  1212 , the upper bottom RU 1  and the insulating layer  1213 . 
     In the example shown in  FIG.  8   , even the reflective layer (for example, Al or Al alloy) RL 2  can be subjected to hole injection into the organic layer OR 2  in terms of work function. 
     In Modified Example 3 as well, advantageous effects similar to those of the first embodiment can be obtained. In addition, the width of the reflective layer RL 2  along the first direction X can be made greater than the width of the reflective layer RL 2  in the first direction X of the first embodiment, and thus the aperture efficiency can be improved by increasing the width of the reflective layer RL 2  along the first direction X. Further, as to the display device DSP of Modified Example 3, the number of processing steps in the formation process of the lower electrode E 12  of the display device DSP of the first embodiment by one. 
     Modified Example 4 
     The display device DSP of Modified Example 4 is different from the display device DSP of each of the embodiment and the modified examples thereof in the configuration of the organic layer OR. 
       FIG.  9    is a cross-sectional view showing a configuration example of a display device  20  according to Modified Example 4.  FIG.  9    illustrates only the configuration necessary for explanation. 
     In the example shown in  FIG.  9   , the organic layer OR 1  and the organic layer OR 2  are separated from each other along the first direction X with a groove penetrating to the insulating layer  1212  therebetween. 
     The organic layer OR 2  and the organic layer OR 3  are separated from each other along the first direction X with a groove penetrating to the insulating layer  1213  therebetween. 
     In the example shown in  FIG.  9   , the upper electrode E 2  is disposed on the organic layer OR and the insulating layer  12 . For example, the upper electrode E 2  covers the organic layer OR 1 , the insulating layer  1212 , the organic layer OR 2 , the insulating layer  1213  and the organic layer OR 3 . The upper electrode E 2  covers, in the groove between the organic layer OR 1  and the organic layer OR 2 , a side surface of the organic layer OR 1 , on the tip side of the arrow along the first direction X, a side surface of the organic layer OR 2 , on an opposite side to the tip of the arrow along the first direction X and an upper surface of the insulating layer  1212 . The upper electrode E 2  covers, in the groove between the organic layer OR 2  and the organic layer OR 3 , a side surface of the organic layer OR 2 , on the tip side of the arrow along the first direction X, a side surface of the organic layer OR 3 , on an opposite side to the tip of the arrow along the first direction X and an upper surface of the insulating layer  1213 . 
     In Modified Example  4  as well, advantageous effects similar to those of the first embodiment can be obtained. 
     Modified Example 5 
     The display device DSP of Modified Example 5 is different from the display device DSP of each of the embodiment and the modified examples thereof in the configuration of the organic layer OR. 
       FIG.  10    is a cross-sectional view showing a configuration example of a display device  20  according to Modified Example 5.  FIG.  10    illustrates only the configuration necessary for explanation. 
     In the example shown in  FIG.  10   , the organic layer OR covers the lower electrode E 1 , the insulating layer  1212  and the insulating layer  1213 . The organic layer OR comprises a functional layer F 1 , a light-emitting layer EL and a functional layer F 2 , which are stacked in the order listed. The light-emitting layer EL is, for example, a white light-emitting layer. 
     In Modified Example 5 as well, advantageous effects similar to those of the first embodiment can be obtained. 
     Second Embodiment 
     The display device DSP of the second embodiment is different from the display device DSP of each of the embodiment described above and the modified examples thereof in the configurations of the organic layer OR and the insulating layer  12 . 
       FIG.  11    is a cross-sectional view showing a configuration example of a display device  20  according to the second embodiment.  FIG.  11    illustrates only the configuration necessary for explanation. 
     In the example shown in  FIG.  11   , the lower electrode E 1  corresponds to the lower electrode E 1  shown in  FIG.  3   . 
     In the example shown in  FIG.  11   , the cross-section of the organic layer OR is, in the X-Z plane, formed into an approximately dome shape including a rounded upper end portion on an opposite side to the tip of the arrow along the first direction X, and a rounded upper end portion on a side of the tip of the arrow along the first direction X. Note that the cross-section of the organic layer OR may be, in the X-Z plane, formed into a shape other than an approximately dome shape. The organic layer OR covers the lower electrode E 1  and the insulating layer  11 . Note that the organic layer OR may cover the lower electrode El. The organic layer OR includes an organic layer OR 2 . The organic layer OR 2  includes a side portion ORS 1  on an opposite side to the tip of the arrow in the first direction X and a side portion ORS 2  on a side of the tip of the arrow in the first direction X. The side portion ORS 1  is equivalent to the portion from the side surface of the organic layer OR 2 , on an opposite side to the tip of the arrow in the first direction X to the end portion of the upper surface of the organic layer OR 2 , on an opposite side to the tip of the arrow in the first direction X. The side portion ORS 2  is equivalent to the portion from the side surface of the organic layer OR 2 , on a side to the tip of the arrow in the first direction X to the end portion of the upper surface of the organic layer OR 2 , on a side to the tip of the arrow in the first direction X. For example, the organic layer OR 2  covers the lower electrode E 12  and the insulating layer  11 . Note that the organic layer OR 2  may cover only the lower electrode E 12 . The organic layer OR 2  covers the upper bottom EU 1 , the side portion ES 11  and the side portion ES 12 . For example, the organic layer OR 2  covers the transparent electrode TE 2 . In other words, the organic layer OR 2  is disposed on the transparent electrode TE 2 . 
     In the example shown in  FIG.  11   , the insulating layer  12  covers the organic layer OR. The insulating layer  12  includes insulating layers  1212  and  1213 . For example, the insulating layer  1212  covers the side portion ORS 1  of the organic layer OR 2 . In other words, the insulating layer  1212  is in contact with the side portion ORS 1 . The insulating layer  1213  covers the side portion ORS 2  of the organic layer OR 2 . In other words, the insulating layer  1213  is in contact with the side portion ORS 2 . 
     In the example shown in  FIG.  11   , the upper electrode E 2  is disposed on the insulating layer  12  and the organic layer OR. For example, the upper electrode E 2  is disposed on the insulating layer  1212 , the organic layer OR 2  and the insulating layer  1213 . 
     In the example shown in  FIG.  11   , the lower electrode E 1  is formed, and thereafter, the organic layer OR is deposited on the lower electrode E 1  and the organic layer OR is subjected to patterning by dry etching. Then, the resultant is planarized, and the insulating layer  12  is applied on the organic layer OR and the insulating layer  11 . Then, patterning is carried out to remove the insulating layer  12  on the organic layer OR. The upper electrode E 2  is then deposited on the organic layer OR and the insulating layer  12 . 
     In the second embodiment as well, advantageous effects similar to those of the first embodiment can be obtained. 
     Modified Example 6 
     The display device DSP of Modified Example 6 is different from the display device DSP of each of the embodiment described above and the modified examples thereof in the configurations of the organic layer OR and the insulating layer  12 . 
       FIG.  12    is a cross-sectional view showing a configuration example of a display device  20  according to Modified Example 6.  FIG.  12    illustrates only the configuration necessary for explanation. 
     In the example shown in  FIG.  12   , the lower electrode E 1  corresponds to the lower electrode E 1  shown in  FIG.  6   . In the example shown in  FIG.  12   , the organic layer OR 2  covers the upper bottom EU 1  and the side portions ES 11  and ES 12  of the lower electrode E 12 . The organic layer OR 2  covers the upper bottom EU 1 , the reflective layer TE 2  which covers the side portion RS 1  and the upper surface CDE 1  of the reflective layer RL 2 , the transparent electrode TE 2  which covers the end portion CDS 1  of the conductive layer CDL 2 , the side portion RS 2  and the upper surface CDE 2  of the reflective layer RL 2 , and the end portion CDS 2  of the conductive layer CDL 2 . 
     In the example shown in  FIG.  12   , the insulating layer  12  corresponds to the insulating layer  12  shown in  FIG.  11   . 
     In Modified Example 6 as well, advantageous effects similar to those of the second embodiment can be obtained. 
     Modified Example 7 
     The display device DSP of Modified Example 7 is different from the display device DSP of each of the embodiment described above and the modified examples thereof in the configurations of the organic layer OR and the insulating layer  12 .  FIG.  13    is a cross-sectional view showing a configuration example of a display device  20  of Modified Example 7.  FIG.  13    illustrates only the configuration necessary for explanation. 
     In the example shown in  FIG.  13   , the lower electrode E 1  corresponds to the lower electrode El shown in  FIG.  7   . In the example shown in  FIG.  13   , the organic layer OR 2  covers the upper surface EU 1  and the side portions ES 11  and ES 12  of the lower electrode E 12 . The organic layer OR 2  covers the upper surface of the transparent electrode TE 2 , the side portion of the conductive layer CDL 2 , on an opposite side to the tip of the arrow along the first direction X, the side portion of the reflective layer RL 2 , on an opposite side to the tip of the arrow along the first direction X, the side portion of the conductive layer CDL 2 , on a side to the tip of the arrow along the first direction X, the side portion of the reflective layer RL 2 , on a side to the tip of the arrow along the first direction X, and the side portion of the transparent electrode TE 2 , on a side to the tip of the arrow along the first direction X. 
     In the example shown in  FIG.  13   , the insulating layer  12  corresponds to the insulating layer  12  shown in  FIG.  11   . 
     In Modified Example 7 as well, advantageous effects similar to those of the second embodiment can be obtained. 
     Modified Example 8 
     The display device DSP of Modified Example 8 is different from the display device DSP of each of the embodiment described above and the modified examples thereof in the configurations of the organic layer OR and the insulating layer  12 . 
       FIG.  14    is a cross-sectional view showing a configuration example of a display device  20  according to Modified Example 8.  FIG.  14    illustrates only the configuration necessary for explanation. 
     In the example shown in  FIG.  14   , the lower electrode E 1  corresponds to the lower electrode E 1  shown in  FIG.  8   . 
     In the example shown in  FIG.  14   , the organic layer OR 2  covers the upper bottom EU 1  and the side portions ES 11  and ES 12  of the lower electrode E 12 . The organic layer OR 2  covers the upper bottom RU 1  of the reflective layer RL 2 , the side portion RS 1  and the side portion RS 2  of the reflective layer RL 2  and the side portions ES 1  and ES 12  of the conductive layer CDL 2 . 
     In the example shown in  FIG.  14   , the insulating layer  12  corresponds to insulating layer  12  shown in  FIG.  11   . 
     In the example shown in  FIG.  14   , the transparent electrode (for example, ITO) TE 2  is not disposed on the reflective layer (for example, Al or Al alloy) RL 2 . With this structure, even if alkaline liquid (for example, developer solution) enters during patterning of the organic layer OR 2  and the insulating layer  12 , deterioration of pixels PX, rise in applied voltage and degradation over time, which may be caused by the reduction of the reflective layer RL 2  and the transparent electrode TE 2  will not occur. In this manner, a brightness efficiency, which is close to that of the display device DSP including a lower electrode E 1 , in which the transparent electrode TE 2  is disposed on the reflective layer RL 2 , can be realized. Further, since the area of the reflective layer RL 2  can be expanded, the aperture ratio can be improved. 
     In Modified Example 8 as well, advantageous effects similar to those of the second embodiment can be obtained. 
     Based on the display device which has been described in the above-described embodiments, a person having ordinary skill in the art may achieve a display device with an arbitral design change; however, as long as they fall within the scope and spirit of the present invention, such a display device is encompassed by the scope of the present invention. 
     A skilled person would conceive various changes and modifications of the present invention within the scope of the technical concept of the invention, and naturally, such changes and modifications are encompassed by the scope of the present invention. For example, if a skilled person adds/deletes/alters a structural element or design to/from/in the above-described embodiments, or adds/deletes/alters a step or a condition to/from/in the above-described embodiment, as long as they fall within the scope and spirit of the present invention, such addition, deletion, and altercation are encompassed by the scope of the present invention. 
     Furthermore, regarding the examples described in the above embodiments, any advantage and effect those will be obvious from the description of the specification or arbitrarily conceived by a skilled person are naturally considered achievable by the present invention.