Display device and electronic equipment

Abstract

Provided is a display device capable of suppressing variation in emission luminance.　This display device is provided with: a first electrode layer having a plurality of electrodes arranged two-dimensionally; a second electrode layer provided opposite the first electrode layer; an electroluminescent layer provided between the first and second electrode layers; and an insulating layer provided between adjacent electrodes. The insulating layer has a plurality of openings. Each of the plurality of openings is provided to a corresponding one of electrodes. The insulating layer includes a plurality of localized portions. Each of the plurality of localized portions is localized around a corresponding one of the openings. The insulating layer forms a potential barrier between the electroluminescent layer and the localized portions.

Description

Technical Field

[0001] The present disclosure relates to a display device and an electronic device including the same.

Background Art

[0002] In recent years, organic EL (Electroluminescence) display devices (hereinafter simply referred to as "display devices") have become widely popular. As such a display device, there has been proposed one in which a first electrode layer and a second electrode layer are arranged to face each other with an organic electroluminescence layer interposed therebetween, and the first electrode layer is composed of a plurality of electrodes separated by an insulating layer (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the display device having the above configuration, there is a problem that the emission luminance fluctuates.

[0005] An object of the present disclosure is to provide a display device capable of suppressing fluctuations in emission luminance and an electronic device including the same.

Means for Solving the Problems

[0006] In order to solve the above problems, a first disclosure is a first electrode layer having a plurality of electrodes arranged two-dimensionally, a second electrode layer provided to face the first electrode layer, an electroluminescence layer provided between the first electrode layer and the second electrode layer, an insulating layer provided between adjacent electrodes, and comprising, The insulating layer has a plurality of openings, and the plurality of openings are respectively provided corresponding to each electrode. The insulating layer includes a plurality of localized portions, and the plurality of localized portions are respectively localized around each opening. The insulating layer is a display device that forms a potential barrier between the electroluminescence layer and the localized portions.

[0007] The second disclosure is an electronic device including the display device of the first disclosure.

Brief Description of the Drawings

[0008]

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[0009] Embodiments of the present disclosure will be described in the following order with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals. 1. One embodiment (example of display device) 2. Modification (modification of display device) 3. Application example (example of electronic device)

[0010] <1. One embodiment> [Configuration of display device] FIG. 1 is a schematic view showing an example of the overall configuration of a display device 10 according to an embodiment of the present disclosure. The display device 10 has a display area 110A and a peripheral area 110B provided at the periphery of the display area 110A. A plurality of sub-pixels 100R, 100G, and 100B are two-dimensionally arranged in a prescribed arrangement pattern such as a matrix in the display area 110A.

[0011] Sub-pixel 100R displays red, sub-pixel 100G displays green, and sub-pixel 100B displays blue. In the following description, when sub-pixels 100R, 100G, and 100B are not particularly distinguished, they are referred to as sub-pixel 100. A combination of adjacent sub-pixels 100R, 100G, and 100B constitutes one pixel. In FIG. 1, an example is shown in which a combination of three sub-pixels 100R, 100G, and 100B arranged in the row direction (horizontal direction) constitutes one pixel.

[0012] In the peripheral region 110B, a signal line driving circuit 111 and a scanning line driving circuit 112, which are drivers for video display, are provided. The signal line driving circuit 111 supplies a signal voltage of a video signal corresponding to luminance information supplied from a signal source (not shown) to the selected sub-pixel 100 via the signal line 111A. The scanning line driving circuit 112 is composed of a shift register or the like that sequentially shifts (transfers) start pulses in synchronization with the input clock pulses. The scanning line driving circuit 112 scans each sub-pixel 100 in row units when writing a video signal thereto, and sequentially supplies a scanning signal to each scanning line 112A.

[0013] The display device 10 may be a microdisplay. The display device 10 may be provided in a VR (Virtual Reality) device, an MR (Mixed Reality) device, an AR (Augmented Reality) device, an electronic viewfinder (Electronic View Finder: EVF), or a small projector or the like.

[0014] FIG. 2 is a cross-sectional view showing an example of the configuration of the display device 10 according to an embodiment of the present disclosure. The display device 10 includes a driving substrate 11, an interlayer insulating layer 12, a first electrode layer 13, an organic electroluminescence layer 14 (hereinafter referred to as "EL layer 14"), a second electrode layer 15, an element insulating layer 16, a protective layer 17, a color filter 18, a filling resin layer 19, and a counter substrate 20.

[0015] The display device 10 is an example of a light-emitting device. The display device 10 is a top-emission type display device. The side of the counter substrate 20 of the display device 10 is the top side, and the side of the driving substrate 11 of the display device 10 is the bottom side. In the following description, in each layer constituting the display device 10, the surface on the top side of the display device 10 is referred to as the first surface, and the surface on the bottom side of the display device 10 is referred to as the second surface.

[0016] The display device 10 includes a plurality of light-emitting elements 10A. The plurality of light-emitting elements 10A are composed of a first electrode layer 13, an EL layer 14, and a second electrode layer 15. The light-emitting element 10A is a white light-emitting element such as a white OLED or a white Micro-OLED (MOLED). As a color conversion method in the display device 10, a method using a white light-emitting element and a color filter 18 is used. However, the color conversion method is not limited to this, and a method of extracting three-color light (red light, green light, blue light) by a resonator structure may be used. By using the color filter 18 and the resonator structure in combination, the color purity may be improved.

[0017] (Driving Substrate) The driving substrate 11 is a so-called backplane and drives a plurality of light-emitting elements 10A. On the first surface of the driving substrate 11, a driving circuit for driving a plurality of light-emitting elements 10A, a power supply circuit for supplying power to the plurality of light-emitting elements 10A, etc. (none of which are shown) are provided.

[0018] The substrate body of the driving substrate 11 may be made of, for example, glass or resin with low permeability to moisture and oxygen, or may be made of a semiconductor that is easy to form transistors or the like. Specifically, the substrate body may be a glass substrate, a semiconductor substrate, a resin substrate, or the like. The glass substrate includes, for example, high strain point glass, soda glass, borosilicate glass, forsterite, lead glass, or quartz glass. The semiconductor substrate includes, for example, amorphous silicon, polycrystalline silicon, or single crystal silicon. The resin substrate includes at least one selected from the group consisting of, for example, polymethyl methacrylate, polyvinyl alcohol, polyvinyl phenol, polyethersulfone, polyimide, polycarbonate, polyethylene terephthalate, and polyethylene naphthalate.

[0019] (Interlayer insulating layer) The interlayer insulating layer 12 (hereinafter simply referred to as "insulating layer 12") is provided on the first surface of the driving substrate 11 and covers the driving circuit, the power supply circuit, and the like. The insulating layer 12 includes a plurality of contact plugs 12A. Each contact plug 12A connects the light-emitting element 10A and the driving circuit. The insulating layer 12 may further include a plurality of wirings (not shown).

[0020] The insulating layer 12 may have a single-layer structure or a laminated structure. The insulating layer 12 may be an organic insulating layer, an inorganic insulating layer, or a laminate thereof. The organic insulating layer includes at least one selected from the group consisting of, for example, polyimide-based resins, acrylic-based resins, and novolak-based resins. The inorganic insulating layer includes at least one selected from the group consisting of, for example, silicon oxide (SiO x ), silicon nitride (SiN x ), and silicon oxynitride (SiO x N y ).

[0021] (First electrode layer) The first electrode layer 13 is provided on the first surface of the insulating layer 12. The first electrode layer 13 is an anode. When a voltage is applied between the first electrode layer 13 and the second electrode layer 15, holes are injected from the first electrode layer 13 into the EL layer 14. The first electrode layer 13 also serves as a reflective layer, and it is preferable for enhancing the luminous efficiency that it is made of a material with as high a reflectivity as possible and a large work function. The first electrode layer 13 has a plurality of electrodes 13A. The plurality of electrodes 13A are electrically separated between adjacent light-emitting elements 10A. The plurality of electrodes 13A share the EL layer 14. The plurality of electrodes 13A are two-dimensionally arranged in a defined arrangement pattern such as a matrix. Each of the plurality of electrodes 13A is connected to each contact plug 12A provided in the insulating layer 12. Through this contact plug 12A, the first electrode layer 13 is connected to a driving circuit or wiring.

[0022] The electrode 13A is composed of at least one of a metal layer and a metal oxide layer. More specifically, the electrode 13A is composed of a single-layer film of a metal layer or a metal oxide layer, or a laminated film of a metal layer and a metal oxide layer. When the electrode 13A is composed of a laminated film, the metal oxide layer may be provided on the EL layer 14 side, or the metal layer may be provided on the EL layer 14 side. However, from the viewpoint of adjacent a layer with a high work function to the EL layer 14, it is preferable that the metal oxide layer is provided on the EL layer 14 side.

[0023] The metal layer contains, for example, at least one metal element selected from the group consisting of chromium (Cr), gold (Au), platinum (Pt), nickel (Ni), copper (Cu), molybdenum (Mo), titanium (Ti), tantalum (Ta), aluminum (Al), magnesium (Mg), iron (Fe), tungsten (W), and silver (Ag). The metal layer may contain the at least one metal element as a constituent element of an alloy. Specific examples of the alloy include an aluminum alloy or a silver alloy. Specific examples of the aluminum alloy include, for example, AlNd or AlCu.

[0024] The metal oxide layer includes, for example, a transparent conductive oxide (TCO: Transparent Conductive Oxide). The transparent conductive oxide includes, for example, at least one selected from the group consisting of a transparent conductive oxide containing indium (hereinafter referred to as "indium-based transparent conductive oxide"), a transparent conductive oxide containing tin (hereinafter referred to as "tin-based transparent conductive oxide"), and a transparent conductive oxide containing zinc (hereinafter referred to as "zinc-based transparent conductive oxide").

[0025] The indium-based transparent conductive oxide includes, for example, indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), or indium gallium zinc oxide (IGZO), fluorine-doped indium oxide (IFO). Among these transparent conductive oxides, indium tin oxide (ITO) is particularly preferred. This is because indium tin oxide (ITO) has a particularly low hole injection barrier to the EL layer 14 in terms of work function, so that the driving voltage of the display device 10 can be particularly reduced. The tin-based transparent conductive oxide includes, for example, tin oxide, antimony-doped tin oxide (ATO), or fluorine-doped tin oxide (FTO). The zinc-based transparent conductive oxide includes, for example, zinc oxide, aluminum-doped zinc oxide (AZO), boron-doped zinc oxide, or gallium-doped zinc oxide (GZO).

[0026] (Second electrode layer) The second electrode layer 15 is provided to face the first electrode layer 13. The second electrode layer 15 is provided as an electrode common to all the sub-pixels 100 within the display region 110A. The second electrode layer 15 is a cathode. When a voltage is applied between the first electrode layer 13 and the second electrode layer 15, electrons are injected from the second electrode layer 15 into the EL layer 14. The second electrode layer 15 is a transparent electrode having transparency to the light generated in the EL layer 14. Here, the transparent electrode is assumed to include a semi-transmissive reflective layer. It is preferable that the second electrode layer 15 is made of a material having as high transparency as possible and a small work function in order to enhance the light emission efficiency.

[0027] The second electrode layer 15 is composed of, for example, at least one layer of a metal layer and a metal oxide layer. More specifically, the second electrode layer 15 is composed of a single-layer film of a metal layer or a metal oxide layer, or a laminated film of a metal layer and a metal oxide layer. When the second electrode layer 15 is composed of a laminated film, the metal layer may be provided on the EL layer 14 side, or the metal oxide layer may be provided on the EL layer 14 side. However, from the viewpoint of adjacent the EL layer 14 with a layer having a low work function, it is preferable that the metal layer is provided on the EL layer 14 side.

[0028] The metal layer contains, for example, at least one metal element selected from the group consisting of magnesium (Mg), aluminum (Al), silver (Ag), calcium (Ca), and sodium (Na). The metal layer may contain the at least one metal element as a constituent element of an alloy. Specific examples of the alloy include MgAg alloy, MgAl alloy, or AlLi alloy. The metal oxide layer contains a transparent conductive oxide. As the transparent conductive oxide, the same materials as the transparent conductive oxide of the electrode 13A described above can be exemplified.

[0029] (EL layer) The EL layer 14 is provided between the first electrode layer 13 and the second electrode layer 15. The EL layer 14 is continuously provided across all the electrodes 13A within the display region 110A and is shared by all the electrodes 13A within the display region 110A. The EL layer 14 is provided as an organic layer common to all the sub-pixels 100 within the display region 110A. The EL layer 14 is configured to be capable of emitting white light.

[0030] The EL layer 14 may be an organic EL layer with a 1-stack structure, an organic EL layer with a 2-stack structure, or an organic EL layer other than these. The organic EL layer with a 1-stack structure has, for example, a structure in which a hole injection layer, a hole transport layer, a red light-emitting layer, a light emission separation layer, a blue light-emitting layer, a green light-emitting layer, an electron transport layer, and an electron injection layer are laminated in this order from the first electrode layer 13 toward the second electrode layer 15. The organic EL layer with a 2-stack structure has, for example, a structure in which a hole injection layer, a hole transport layer, a blue light-emitting layer, an electron transport layer, a charge generation layer, a hole transport layer, a yellow light-emitting layer, an electron transport layer, and an electron injection layer are laminated in this order from the first electrode layer 13 toward the second electrode layer 15.

[0031] The hole injection layer is for enhancing the hole injection efficiency into each light-emitting layer and suppressing leakage. The hole transport layer is for enhancing the hole transport efficiency to each light-emitting layer. The electron injection layer is for enhancing the electron injection efficiency into each light-emitting layer. The electron transport layer is for enhancing the electron transport efficiency to each light-emitting layer. The light emission separation layer is a layer for adjusting the injection of carriers into each light-emitting layer, and the injection of electrons and holes into each light-emitting layer through the light emission separation layer adjusts the light emission balance of each color. The charge generation layer supplies electrons and holes to two light-emitting layers sandwiching the charge generation layer, respectively.

[0032] The red light-emitting layer, the green light-emitting layer, the blue light-emitting layer, and the yellow light-emitting layer each cause recombination of holes injected from the electrode 13A and electrons injected from the second electrode layer 15 by applying an electric field, and generate red light, green light, blue light, and yellow light.

[0033] (Inter-element insulating layer) Figure 3 is an enlarged cross-sectional view of the region R in Figure 2. Figure 4 is an energy diagram of each layer included in the cross-section along line IV-IV in Figure 3. The inter-element insulating layer 16 (hereinafter simply referred to as "insulating layer 16") is provided on the first surface of the insulating layer 12 and between adjacent first electrode layers 13, and electrically separates between adjacent electrodes 13A.

[0034] The insulating layer 16 has a plurality of openings 16H. The plurality of openings 16H are each provided corresponding to each sub-pixel 100. The plurality of openings 16H are each provided on the first surface of each electrode 13A (i.e., the surface facing the second electrode layer 15), exposing the first surface of each electrode 13A. Through the opening 16H, the first electrode layer 13 and the EL layer 14 are in contact. The peripheral surface of the opening 16H may be an inclined surface inclined with respect to the first surface of the electrode 13A. One opening 16H may be provided for one electrode 13A, or two or more openings 16H may be provided for one electrode 13A. The insulating layer 16 covers from the peripheral portion of the first surface of the electrode 13A to the side surface (end face) of the electrode 13A. In this specification, the peripheral portion of the first surface refers to a region having a predetermined width from the periphery of the first surface toward the inside.

[0035] The insulating layer 16 includes an insulating layer main body 16A, a barrier layer 16B, and a plurality of localization portions 16C. The insulating layer 16 forms a potential barrier between the EL layer 14 and the localization portions 16C. Thereby, it is possible to suppress carriers trapped in the localization portions 16C from being detrapped from the localization portions 16C to the EL layer 14. Therefore, reversible luminance fluctuations can be suppressed. In this embodiment, the case where the carriers are electrons will be described. The potential barrier formed between the EL layer 14 and the localization portions 16C is configured such that when a voltage is applied between the first electrode layer 13 and the second electrode layer 15, carriers can tunnel from the EL layer 14 to the localization portions 16C.

[0036] Preferably, the insulating layer 16 forms a potential barrier around the localization portions 16C. That is, preferably, the localization portions 16C form a well-type potential within the insulating layer 16. In this case, it is possible to suppress carriers trapped in the localization portions 16C from being detrapped from the localization portions 16C to surrounding members such as the EL layer 14 and the electrode 13A.

[0037] (Barrier layer) The barrier layer 16B is provided between the insulating layer main body 16A and the EL layer 14, and between the localized portion 16C and the EL layer 14. The barrier layer 16B forms a potential barrier between the EL layer 14 and the localized portion 16C. The lower limit value of the height of the potential barrier with respect to the localized portion 16C (i.e., the energy barrier difference between the localized portion 16C and the barrier layer 16B) is preferably 1 eV or more. The upper limit value of the height of the potential barrier with respect to the localized portion 16C (i.e., the energy barrier difference between the localized portion 16C and the barrier layer 16B) is, for example, 5 eV or less. The height of the potential barrier with respect to the EL layer 14 (i.e., the energy barrier difference between the EL layer 14 and the barrier layer 16B) is preferably 1 eV or less. When the height of the potential barrier with respect to the localized portion 16C is 1 eV or more, it is possible to suppress the detrapping of carriers trapped in the localized portion 16C from the localized portion 16C to the EL layer 14. When the height of the potential barrier with respect to the EL layer 14 is 1 eV or less, it is possible to suppress a decrease in the number of carriers trapped from the EL layer 14 to the localized portion 16C through the potential barrier.

[0038] The height of the potential barrier with respect to the localized portion 16C and the height of the potential barrier with respect to the EL layer 14 are obtained as follows. For a stacked structure composed of the EL layer 14, the insulating layer main body 16A, the barrier layer 16B, the localized portion 16C, etc., it can be obtained by using photoelectron spectroscopy or inverse photoelectron spectroscopy.

[0039] The barrier layer 16B may be composed of the same material as the insulating layer main body 16A, or may be composed of a material different from the insulating layer main body 16A. The barrier layer 16B contains, for example, silicon oxide (SiO x ).

[0040] The average thickness of the barrier layer 16B (i.e., the average distance between the EL layer 14 and the localized portion 16C) is preferably 2 nm or more and 5 nm or less. When the average thickness of the barrier layer 16B is 2 nm or more, it is possible to suppress the detrapping of carriers trapped in the localized portion 16C from the localized portion 16C to the EL layer 14. On the other hand, when the average thickness of the barrier layer 16B is 5 nm or less, it is possible to suppress a decrease in the number of carriers trapped from the EL layer 14 to the localized portion 16C through the potential barrier.

[0041] The average thickness of the barrier layer 16B (i.e., the average distance between the EL layer 14 and the localized portion 16C) is obtained as follows. First, a cross-section of the display device 10 (a cross-section parallel to the thickness direction of the display device 10) is cut out by cryo-FIB (Focused Ion Beam) processing or the like to produce a thin slice. Subsequently, the produced thin slice is observed with a TEM (Transmission Electron Microscope) to obtain one cross-sectional TEM image. At this time, the acceleration voltage is set to 80 kV. Next, in the obtained one cross-sectional TEM image, the thickness D (see FIG. 3) of the portion of the barrier layer 16B located between the EL layer 14 and the localized portion 16C is measured at 10 or more points. At this time, each measurement position is randomly selected from the portion of the barrier layer 16B located between the EL layer 14 and the localized portion 16C. Then, the average thickness of the barrier layer 16B is obtained by simply averaging (arithmetic mean) the thicknesses of the barrier layer 16B measured at 10 or more points.

[0042] (Insulating layer body) The insulating layer body 16A preferably forms a potential barrier between the localized portion 16C and the electrode 13A. By forming a potential barrier between the localized portion 16C and the electrode 13A, it is possible to suppress the detrapping of carriers from the localized portion 16C to the electrode 13A. The lower limit value of the height of the potential barrier with respect to the localized portion 16C (i.e., the energy barrier difference between the localized portion 16C and the insulating layer body 16A) is preferably 1 eV or more. When the height of the potential barrier is 1 eV or more, it is possible to suppress the detrapping of carriers trapped in the localized portion 16C from the localized portion 16C to the electrode 13A or the like. The upper limit value of the height of the potential barrier is not particularly limited, but is, for example, 5 eV or less. The barrier layer 16B contains, for example, silicon oxide (SiO x ). The energy barrier difference between the localized portion 16C and the insulating layer body 16A can be obtained in the same manner as the energy barrier difference between the localized portion 16C and the barrier layer 16B.

[0043] (Localized portion) The localized portion 16C has a plurality of trap levels for trapping carriers in the forbidden band (band gap). The localized portion 16C traps carriers that have reached from the EL layer 14 through the barrier layer 16B at a plurality of trap levels. The LUMO (Lowest Unoccupied Molecular Orbital) of the localized portion 16C may be higher than the LUMO of the EL layer 14.

[0044] Each of the plurality of localized portions 16C is provided on the first surface of each electrode 13A (i.e., the surface facing the second electrode layer 15). Each of the plurality of localized portions 16C is localized around each opening 16H of the insulating layer 16. Since carrier trapping is likely to occur in the portion around the opening 16H of the insulating layer 16, by providing the localized portion 16C around the opening 16H of the insulating layer 16, the leakage current can be reduced. The localized portion 16C is preferably provided adjacent to the barrier layer 16B.

[0045] The localized portion 16C may have a closed-loop shape surrounding the opening 16H of the insulating layer 16, or may be discontinuously provided in a scattered manner so as to surround the opening 16H of the insulating layer 16. The localized portion 16C is preferably surrounded by an insulating material (e.g., silicon oxide (SiO x )) contained in the insulating layer 16. More specifically, the localized portion 16C is preferably adjacent to the peripheral surface of the opening 16H of the insulating layer 16 via the barrier layer 16B.

[0046] The localized portion 16C is preferably separated from the first surface of the electrode 13A. Thereby, it is possible to suppress carriers trapped in the localized portion 16C from being detrapped from the localized portion 16C to the electrode 13A. The shortest distance between the first electrode layer 13 and the localized portion 16C is preferably equal to or greater than the average thickness of the barrier layer 16B from the viewpoint of suppressing the detrapping of carriers from the localized portion 16C to the electrode 13A.

[0047] The localized portion 16C contains an insulating material different from that of the barrier layer 16B. The localized portion 16C contains, for example, at least one selected from the group consisting of silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), hafnium oxide (HfO x ), aluminum oxide (AlO x ), and tantalum oxide (TaO x ).

[0048] (Protective layer) The protective layer 17 is provided on the first surface of the second electrode layer 15 and covers the plurality of light-emitting elements 10A. The protective layer 17 blocks the light-emitting elements 10A from the outside air and suppresses the intrusion of moisture from the external environment into the light-emitting elements 10A. Further, when the second electrode layer 15 is composed of a metal layer, the protective layer 17 may have a function of suppressing the oxidation of this metal layer.

[0049] The protective layer 17 is composed of, for example, an inorganic material with low hygroscopicity. The inorganic material includes, for example, at least one of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiNO), titanium oxide (TiO), and aluminum oxide (AlO). The protective layer 17 may have a single-layer structure, but when the thickness of the protective layer 17 is increased, it may also have a multilayer structure. This is for relaxing the internal stress in the protective layer 17. The protective layer 17 may be composed of a polymer resin. The polymer resin includes at least one selected from the group consisting of thermosetting resins and ultraviolet curable resins, etc.

[0050] (Color Filter) The color filter 18 is provided on the first surface of the protective layer 17. The color filter 18 is, for example, an on-chip color filter (OCCF). The color filter 18 includes, for example, a red filter, a green filter, and a blue filter. The red filter, the green filter, and the blue filter are respectively provided facing the light-emitting element 10A. The red filter and the light-emitting element 10A constitute the sub-pixel 100R, the green filter and the light-emitting element 10A constitute the sub-pixel 100G, and the blue filter and the light-emitting element 10A constitute the sub-pixel 100B.

[0051] The white light emitted from each light-emitting element 10A within the sub-pixels 100R, 100G, and 100B passes through the above-mentioned red filter, green filter, and blue filter respectively, so that red light, green light, and blue light are respectively emitted from the display surface. Also, a light-shielding layer (not shown) may be provided in the region between color filters of each color, that is, between sub-pixels. Note that the color filter 18 is not limited to an on-chip color filter and may be provided on one main surface of the counter substrate 20.

[0052] (Filling Resin Layer) The filling resin layer 19 is provided between the color filter 18 and the counter substrate 20. The filling resin layer 19 has a function as an adhesive layer for adhering the color filter 18 and the counter substrate 20. The filling resin layer 19 contains at least one selected from the group consisting of, for example, thermosetting resins and ultraviolet curable resins.

[0053] (Counter substrate) The counter substrate 20 is provided to face the driving substrate 11. More specifically, the counter substrate 20 is provided such that the second surface of the counter substrate 20 faces the first surface of the driving substrate 11. The counter substrate 20 and the filling resin layer 19 seal the light emitting element 10A, the color filter 18, and the like. The counter substrate 20 is made of a material such as glass that is transparent to each color light emitted from the color filter 18.

[0054] [Manufacturing method of display device] Hereinafter, with reference to FIGS. 5A to 5C and FIGS. 6A and 6B, an example of a manufacturing method of the display device 10 according to an embodiment of the present disclosure will be described.

[0055] First, for example, using thin film formation technology, photolithography technology, and etching technology, a driving circuit, a power supply circuit, and the like are formed on the first surface of the substrate body. Thereby, the driving substrate 11 is obtained. Next, for example, by a CVD (Chemical Vapor Deposition) method, an insulating layer 12 is formed on the first surface of the driving substrate 11 so as to cover the driving circuit, the power supply circuit, and the like. At this time, a plurality of contact plugs 12A, a plurality of wirings, and the like are formed in the insulating layer 12.

[0056] Next, for example, by a sputtering method, a metal layer and a metal oxide layer are sequentially formed on the first surface of the insulating layer 12, and then the metal layer and the metal oxide layer are patterned using, for example, photolithography technology and etching technology. Thereby, the first electrode layer 13 having a plurality of electrodes 13A is formed.

[0057] Next, for example, by the plasma CVD method, as shown in FIG. 5A, an insulating layer 16D is formed on the first surface of the insulating layer 12 so as to cover the plurality of electrodes 13A. Next, for example, by photolithography technology and dry etching technology, as shown in FIG. 5B, recesses 16F are respectively formed in portions of the insulating layer 16D that are located on the first surfaces of the respective electrodes 13A. At this time, the formation positions of the respective recesses 16F are adjusted so that the recesses 16F are located inside the periphery of the first surface of the electrode 13A.

[0058] Next, for example, by the plasma CVD method, as shown in FIG. 5C, an insulating layer 16E is formed on the first surface of the insulating layer 16D so as to follow each recess 16F. Next, for example, by etch-back, as shown in FIG. 6A, openings 16H are respectively formed on the first surfaces of the plurality of electrodes 13A. At this time, a part of the insulating layer 16E remains on the peripheral surface (inclined surface) of the opening 16H, and a localized portion 16C is formed by this residue. Next, for example, by plasma treatment, as shown in FIG. 6B, the insulating layer 16D and the localized portion 16C are surface-treated to form a barrier layer 16B. Thereby, the insulating layer 16 is obtained.

[0059] Next, for example, by vapor deposition, a hole injection layer, a hole transport layer, a red light-emitting layer, a light-emitting separation layer, a blue light-emitting layer, a green light-emitting layer, an electron transport layer, and an electron injection layer are laminated in this order on the first surface of the electrode 13A and the first surface of the insulating layer 16 to form an EL layer 14. Next, for example, by vapor deposition or sputtering, a second electrode layer 15 is formed on the first surface of the EL layer 14. Thereby, a plurality of light-emitting elements 10A are formed on the first surface of the insulating layer 12.

[0060] Next, for example, by a CVD method or a vapor deposition method, after forming the protective layer 17 on the first surface of the second electrode layer 15, a color filter 18 is formed on the first surface of the protective layer 17, for example, by photolithography. In order to planarize the steps due to the steps of the protective layer 17 and the film thickness difference of the color filter 18 itself, a planarization layer may be formed above, below, or both above and below the color filter 18. Next, for example, using an ODF (One Drop Fill) method, after covering the color filter 18 with the filling resin layer 19, the counter substrate 20 is placed on the filling resin layer 19. Next, for example, heat is applied to the filling resin layer 19 or ultraviolet rays are irradiated to the filling resin layer 19 to cure the filling resin layer 19, whereby the driving substrate 11 and the counter substrate 20 are bonded together through the filling resin layer 19. Thereby, the display device 10 is sealed. As described above, the display device 10 shown in FIG. 2 is obtained.

[0061] [Operational Effects] To facilitate the understanding of the operational effects of the display device 10 according to an embodiment, the configurations of the display devices 410 and 510 according to Comparative Examples 1 and 2 are compared with the configuration of the display device 10 according to an embodiment, and the operational effects of the display device 10 will be described.

[0062] In the display device 410 according to Comparative Example 1, as shown in FIG. 7, a plurality of sub-pixels 100 share the EL layer 14. In the display device 410 having such a configuration, when a known interlayer insulating layer 416 is provided as the interlayer insulating layer, carriers flow from the electrode 13A to the interface between the EL layer 14 and the interlayer insulating layer 516 and leak. When the carriers leak in this way, abnormal light emission occurs around the opening 16H of the interlayer insulating layer 416.

[0063] In order to suppress the occurrence of the above abnormal light emission, the present inventors have studied a display device 510 according to Comparative Example 2 provided with an interlayer insulating layer 516 having many trap levels (defect levels) as the interlayer insulating layer, as shown in FIG. 8. As the interlayer insulating layer 516, for example, silicon nitride (SiN) formed by plasma CVD or the like x) is used. By providing such an interlayer insulating layer 516 with many trap levels, the interfacial conductivity between the EL layer 14 and the interlayer insulating layer 516 is reduced, and carrier leakage is suppressed.

[0064] However, in the display device 510 according to Comparative Example 2, carriers are trapped and detrapped in the interlayer insulating layer 516. Along with this, a phenomenon occurs in which the leakage current fluctuates reversibly according to the amount of trapped charge, and as a result, a reversible change in luminance occurs.

[0065] As described above, in the display device 10 according to one embodiment, as shown in FIG. 2, the insulating layer 16 includes a localized portion 16C that is localized around the opening 16H of the insulating layer 16, and a barrier layer 16B provided between the EL layer 14 and the localized portion 16C. The barrier layer 16B forms a potential barrier for carriers between the EL layer 14 and the localized portion 16C. Thereby, carriers once trapped from the EL layer 14 to the localized portion 16C are not easily detrapped from the localized portion 16C to the EL layer 14 and remain in the localized portion 16C. Therefore, reversible fluctuations in the leakage current can be suppressed, and thus reversible fluctuations in luminance can be suppressed.

[0066] <2 Modification Example> (Modification Example 1) In the above-described embodiment, an example in which the peripheral surface of the opening 16H of the insulating layer 16 is an inclined surface has been described. However, the peripheral surface of the opening 16H of the insulating layer 16 may be a vertical surface that is substantially perpendicular to the first surface of the electrode 13A, as shown in FIG. 9. In this case, the localized portion 16C may be adjacent to both the peripheral surface of the opening 16H of the insulating layer 16 and the first surface (upper surface) of the insulating layer 16 with the barrier layer 16B interposed therebetween. The first surface of the insulating layer 16 is the surface on the top side of the display device 10 as described above, and is also the opposing surface facing the second electrode layer 15.

[0067] As shown in FIG. 9, the thickness D1 of the barrier layer 16B on the first surface (upper surface) of the insulating layer 16 and the thickness D2 of the barrier layer 16B on the peripheral surface of the opening 16H of the insulating layer 16 may be substantially constant. Alternatively, as shown in FIG. 10, the thickness D1 of the barrier layer 16B on the first surface (upper surface) of the insulating layer 16 may be greater than the thickness D2 of the barrier layer 16B on the peripheral surface of the opening 16H of the insulating layer 16. When the thickness D1 is greater than the thickness D2, it is possible to suppress the carriers trapped in the localized portion 16C from being emitted from the first surface (upper surface) of the insulating layer 16 toward the second electrode layer 15 (upward in FIG. 10).

[0068] Note that, also in the above-described embodiment, the thickness D1 and the thickness D2 may be substantially the same, or the thickness D1 may be greater than the thickness D2.

[0069] (Modification 2) In the above-described embodiment, an example in which the insulating layer 16 covers the peripheral portion of the first surface of the electrode 13A has been described with reference to FIG. 3. However, as shown in FIG. 11, the insulating layer 16 may not cover the peripheral portion of the first surface of the electrode 13A. That is, the entire first surface of the electrode 13A may be exposed from the insulating layer 16 through the opening 16H. The localized portion 16C may face the side surface of the electrode 13A. The localized portion 16C may be adjacent to the first surface of the insulating layer 16 with the barrier layer 16B interposed therebetween. The first surface (upper surface) of the electrode 13A and the first surface (upper surface) of the barrier layer 16B may be substantially at the same height. From the viewpoint of suppressing a decrease in the number of carriers trapped in the localized portion 16C, the localized portion 16C is preferably provided in a range within 10 nm from the side surface of the electrode 13A. In this case, the entire localized portion 16C may be provided in the above range, or a part of the localized portion 16C may be provided in the above range.

[0070] (Modification 3) In the above-described embodiment, an example in which the insulating layer 16 includes the insulating layer main body 16A and the barrier layer 16B has been described. However, the insulating layer main body 16A and the barrier layer 16B may be integrated, and an interface may not be provided between the insulating layer main body 16A and the barrier layer 16B.

[0071] (Modification Example 4) In the above-described embodiment, an example in which the insulating layer 16 includes a localization portion 16C that traps electrons as carriers has been described. However, the insulating layer 16 may be provided with a localization portion that traps holes as carriers instead of the localization portion 16C. Alternatively, the insulating layer 16 may be provided with a localization portion that traps holes as carriers together with the localization portion 16C. In this case, the localization portion 16C may be provided around the opening 16H of the insulating layer 16. The localization portion that traps holes has a plurality of trap ranks for trapping holes.

[0072] (Modification Example 5) In the above-described embodiment, an example in which the localization portion 16C includes an insulating material has been described. However, the localization portion 16C may include a conductive material such as metal.

[0073] <3 Application Example> (Electronic Device) The display device 10 according to the above-described embodiment and its modification examples can be used in various electronic devices. The display device 10 is incorporated into various electronic devices as a module as shown in FIG. 12, for example. In particular, it is suitable for those that require high resolution such as an electronic viewfinder or a head-mounted display of a video camera or a single-lens reflex camera and are used enlarged near the eyes. This module has a region 210 that is not covered by the counter substrate 20 or the like and is exposed on one short side of the driving substrate 11. Wiring of the signal line driving circuit 111 and the scanning line driving circuit 112 is extended to this region 210 to form external connection terminals (not shown). A flexible printed circuit (FPC) 220 for inputting and outputting signals may be connected to the external connection terminals.

[0074] (Specific Example 1) Figs. 13A and 13B show an example of the appearance of the digital still camera 310. This digital still camera 310 is of the interchangeable-lens single-lens reflex type, and has an interchangeable photographing lens unit (interchangeable lens) 312 at approximately the center of the front of the camera body (camera body) 311, and a grip portion 313 for the photographer to hold on the left side of the front.

[0075] A monitor 314 is provided at a position shifted from the center to the left side on the back of the camera body 311. An electronic viewfinder (eyepiece window) 315 is provided above the monitor 314. The photographer can view the optical image of the subject guided from the photographing lens unit 312 through the electronic viewfinder 315 and determine the composition. As the electronic viewfinder 315, the display device 10 can be used.

[0076] (Specific Example 2) Fig. 14 shows an example of the appearance of the head-mounted display 320. The head-mounted display 320 has, for example, ear-hanging portions 322 for wearing on the user's head on both sides of the spectacle-shaped display portion 321. As the display portion 321, the display device 10 can be used.

[0077] (Specific Example 3) Fig. 15 shows an example of the appearance of the television device 330. This television device 330 has, for example, a video display screen portion 331 including a front panel 332 and a filter glass 333, and this video display screen portion 331 is constituted by the display device 10.

[0078] As described above, one embodiment of the present disclosure and its modified examples have been specifically described. However, the present disclosure is not limited to the above-described one embodiment and its modified examples, and various modifications based on the technical idea of the present disclosure are possible.

[0079] For example, the configurations, methods, processes, shapes, materials, numerical values, etc. described in the above-described embodiment and its modifications are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, etc. may be used as necessary.

[0080] The configurations, methods, processes, shapes, materials, numerical values, etc. of the above-described embodiment and its modifications can be combined with each other as long as they do not deviate from the gist of the present disclosure.

[0081] The materials exemplified in the above-described embodiment and its modifications can be used singly or in combination of two or more without particular notice.

[0082] In addition, the present disclosure can also adopt the following configurations. (1) A first electrode layer having a plurality of two-dimensionally arranged electrodes, A second electrode layer provided facing the first electrode layer, An electroluminescence layer provided between the first electrode layer and the second electrode layer, An insulating layer provided between adjacent electrodes, Comprising, The insulating layer has a plurality of openings, and the plurality of openings are respectively provided corresponding to each of the electrodes, The insulating layer includes a plurality of localized portions, and the plurality of localized portions are respectively localized around each of the openings, A display device in which the insulating layer forms a potential barrier between the electroluminescence layer and the localized portion. (2) The insulating layer contains an insulating material, The display device according to (1), wherein the localized portion is surrounded by the insulating material. (3) The display device according to (2), wherein the insulating layer forms the potential barrier around the localized portion. (4) The localization part contains at least one selected from the group consisting of silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, and tantalum oxide. The insulating material contains silicon oxide. The display device according to (2) or (3). (5) The insulating layer has an insulating layer main body, and a barrier layer provided between the insulating layer main body and the electroluminescence layer. It is provided with The localization part is provided adjacent to the barrier layer. The display device according to any one of (1) to (4), wherein the barrier layer forms the potential barrier. (6) The electrode has a facing surface facing the second electrode layer. The display device according to any one of (5), wherein the localization part is provided on the facing surface. (7) The insulating layer has a facing surface facing the second electrode layer, and the thickness of the barrier layer on the facing surface is thicker than the thickness of the barrier layer on the peripheral surface of the opening. The display device according to (6). (8) The display device according to any one of (1) to (5), wherein the localization part faces the side surface of the electrode. (9) The height of the potential barrier for the localization part is 1 eV or more and 5 eV or less. The display device according to any one of (1) to (8), wherein the height of the potential barrier for the electroluminescence layer is 1 eV or less. (10) The average distance between the electroluminescence layer and the localization part is 2 nm or more and 5 nm or less. The display device according to any one of (1) to (9). (11) The display device according to any one of (1) to (10), wherein the electroluminescence layer is continuously provided across the plurality of electrodes. (12) The localization part is the display device according to any one of (1) to (11) having a trap rank for trapping carriers. (13) The carrier is an electron in the display device according to (12). (14) An electronic device including the display device according to any one of (1) to (13).

Explanation of symbols

[0083] 10, 410, 510 Display device 10A Light-emitting element 11 Driving substrate 12 Interlayer insulating layer 13 First electrode layer 13A Electrode 14 Organic electroluminescence layer 15 Second electrode layer 16, 416, 516 Element isolation layer 16A Insulating layer body 16B Barrier layer 16C Localization part 16D, 16E Insulating layer 16F Recess 16H Opening 17 Protection layer 18 Color filter 19 Filling resin layer 20 Counter substrate 100R, 100G, 100B Sub-pixels 110A Display area 110B Peripheral area 111 Signal line driving circuit 111A Signal line 112 Scanning line driving circuit 112A Scanning line 310 Digital still camera (electronic device) 320 Head-mounted display (electronic device) 330 Television device (electronic device)

Claims

1. A first electrode layer having a plurality of electrodes arranged two-dimensionally, a second electrode layer provided facing the first electrode layer, an electroluminescence layer provided between the first electrode layer and the second electrode layer, and an insulating layer provided between adjacent ones of the electrodes, wherein the insulating layer has a plurality of openings, each of the plurality of openings being provided corresponding to each of the electrodes, the insulating layer includes a plurality of localized portions, each of the plurality of localized portions being localized around each of the openings, and the insulating layer forms a potential barrier between the electroluminescence layer and the localized portions. A display device.

2. The insulating layer contains an insulating material, and the localized portion is surrounded by the insulating material. The display device according to claim 1.

3. The insulating layer forms the potential barrier around the localized portion. The display device according to claim 2.

4. The localized portion includes at least one selected from the group consisting of silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, and tantalum oxide, and the insulating material contains silicon oxide. The display device according to claim 2.

5. The insulating layer includes an insulating layer main body, and a barrier layer provided between the insulating layer main body and the electroluminescence layer, wherein the localized portion is provided adjacent to the barrier layer, and the barrier layer forms the potential barrier. The display device according to claim 1.

6. The electrode has a facing surface facing the second electrode layer, and the localized portion is provided on the facing surface. The display device according to claim 5.

7. The insulating layer has a facing surface facing the second electrode layer, and the thickness of the barrier layer on the facing surface is thicker than the thickness of the barrier layer on the peripheral surface of the opening. The display device according to claim 6.

8. The localized portion faces the side surface of the electrode. The display device according to claim 1.

9. The height of the potential barrier with respect to the localized portion is 1 eV or more and 5 eV or less, and the height of the potential barrier with respect to the electroluminescence layer is 1 eV or less. The display device according to claim 1.

10. The average distance between the electroluminescence layer and the localized portion is 2 nm or more and 5 nm or less. The display device according to claim 1.

11. ​ ​ The display device according to claim 1, wherein the electroluminescent layer is continuously provided across the plurality of electrodes.

12. The display device according to claim 1, wherein the localized portion has a trap rank for trapping carriers.

13. The display device according to claim 12, wherein the carrier is an electron.

14. An electronic device including the display device according to claim 1.

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