OLED light-emitting device, display device, electronic device, and method for manufacturing OLED light-emitting device

Abstract

To suppress deterioration of emission quality due to crosstalk between elements.SOLUTION: A first stack structure light emitting element includes two light emitting units and a first charge generation layer between them. A second stack structure light emitting element includes two light emitting units and a second charge generation layer between them. The first charge generation layer and the second charge generation layer are each composed of one or more charge generation constituent layers. The first end of the first charge generation layer and the second end of the second charge generation layer overlap on the top surface of a device separation layer. In the portion where the first end and the second end overlap, between the charge generation constituent layers that generate charges of the same polarity in the first charge generation layer and the second charge generation layer, the end portion of a constituent layer of the first stack structure light emitting element or the second stack structure light emitting element, which is the constituent layer that shields the charge of the same polarity is interposed.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The present disclosure relates to OLED light-emitting devices. [Background technology]

[0002] OLED (Organic Light-Emitting Diode) elements are current-driven, self-emitting elements that do not require a backlight and have the advantages of low power consumption, a wide viewing angle, and a high contrast ratio. OLED elements are therefore expected to be used in the development of light-emitting devices such as flat panel displays and light source devices.

[0003] A structure in which multiple light-emitting units having OLED structures of the same or different colors are stacked is known. Stacking light-emitting units of the same color can achieve a longer life and higher brightness for the OLED light-emitting device. Furthermore, for example, stacking red, blue, and green light-emitting units can form a white light-emitting device. Light-emitting elements (pixels) having a stacked structure are disclosed, for example, in Patent Documents 1 and 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2015 / 0357388 [Patent Document 2] U.S. Patent Application Publication No. 2018 / 0190731 Summary of the Invention [Problem to be solved by the invention]

[0005] Light-emitting elements with a stacked structure require a charge-generation layer between the light-emitting units. The charge-generation layer supplies electrons to one light-emitting unit and holes to the other unit. However, charge leakage between adjacent light-emitting elements through the charge-generation layer can occur. Crosstalk between light-emitting elements due to charge leakage reduces the luminescence quality of OLED light-emitting devices. [Means for solving the problem]

[0006] An OLED light-emitting device according to one embodiment of the present disclosure includes an isolation layer including openings defining light-emitting regions and a top surface between the openings; a bottom electrode exposed in the opening; a first stacked light-emitting element disposed on the first bottom electrode; and a second stacked light-emitting element disposed on a second bottom electrode adjacent to the first stacked light-emitting element and adjacent to the first bottom electrode. The first stacked light-emitting element includes first and second light-emitting units stacked above the isolation layer, and a first charge generation layer between the first and second light-emitting units. The first and second light-emitting units each include a light-emitting layer. The first charge generation layer supplies charges of one polarity to the first light-emitting unit and charges of the other polarity to the second light-emitting unit. The second stacked light-emitting element includes third and fourth light-emitting units stacked above the isolation layer, and a second charge generation layer between the third and fourth light-emitting units. The third and fourth light-emitting units each include a light-emitting layer. The second charge generation layer supplies charges of the one polarity to the third light-emitting unit and charges of the other polarity to the fourth light-emitting unit. The first charge generation layer and the second charge generation layer are each composed of one or more charge generation constituent layers. A first end of the first charge generation layer and a second end of the second charge generation layer overlap on the top surface of the element isolation layer. At the overlapping portion between the first end and the second end, an end of a constituent layer of the first stacked structure light-emitting element or the second stacked structure light-emitting element that shields charges of the same polarity is interposed between the charge generation constituent layers that generate charges of the same polarity in the first charge generation layer and the second charge generation layer, respectively.

[0007] According to one embodiment of the present disclosure, a method for manufacturing an OLED light-emitting device includes forming a lower electrode, forming an isolation layer including openings defining light-emitting regions and top surfaces between the openings, such that the lower electrodes are exposed through the openings, and forming adjacent first and second stacked light-emitting elements on the isolation layer. The first stacked light-emitting element includes first and second light-emitting units stacked above the isolation layer, and a first charge generation layer between the first and second light-emitting units. The first and second light-emitting units each include a light-emitting layer. The first charge generation layer supplies charges of one polarity to the first light-emitting unit and charges of the other polarity to the second light-emitting unit. The second stacked light-emitting element includes third and fourth light-emitting units stacked above the isolation layer, and a second charge generation layer between the third and fourth light-emitting units. The third and fourth light-emitting units each include a light-emitting layer. The second charge generation layer supplies charges of the one polarity to the third light-emitting unit and charges of the other polarity to the fourth light-emitting unit. The first charge generation layer and the second charge generation layer are each composed of one or more charge generation constituent layers. A first end of the first charge generation layer and a second end of the second charge generation layer overlap on the top surface of the element isolation layer. In the overlapping portion between the first end and the second end, an end of a constituent layer of the first stacked structure light-emitting element or the second stacked structure light-emitting element that shields charges of the same polarity is interposed between the charge generation constituent layers that generate charges of the same polarity in the first charge generation layer and the second charge generation layer, respectively. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, it is possible to suppress degradation of light emission quality due to crosstalk between light-emitting elements. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows a schematic configuration example of an OLED display device. [Figure 2A] 1 shows a plan view of a part of a stack structure light emitting element array. [Figure 2B] 2B is a schematic diagram showing a cross-sectional structure taken along the line IIB-IIB in FIG. 2A. [Figure 2C] An enlarged view of the area enclosed by the dashed circle IIC in FIG. 2B is shown. [Figure 3A] 10A and 10B are cross-sectional views showing different configuration examples of charge generation layers of adjacent stacked light-emitting elements. [Figure 3B] 3B shows an enlarged view of the area enclosed by the dashed circle IIIB in FIG. 3A. [Figure 4] 10A and 10B are schematic diagrams showing opening patterns of a metal mask that can be used to generate a charge generating layer. [Figure 5] 10A and 10B are schematic diagrams showing other examples of opening patterns of a metal mask that can be used to form a charge generating layer. [Figure 6] 10 shows a flow chart of a portion of the manufacturing process after forming the pixel defining layer. [Figure 7A] 10A and 10B are cross-sectional views showing different configuration examples of adjacent stacked structure light-emitting elements. [Figure 7B] 7B shows an enlarged view of the area enclosed by the dashed circle VIIB in FIG. 7A. [Figure 8A] 10A and 10B are cross-sectional views showing different configuration examples of adjacent stacked structure light-emitting elements. [Figure 8B] 8B shows an enlarged view of the area enclosed by the dashed circle VIIIB in FIG. 8A. [Figure 9A] 10A and 10B are cross-sectional views showing different configuration examples of adjacent stacked structure light-emitting elements. [Figure 9B] 9B is an enlarged view of the area surrounded by the dashed circle IXB in FIG. 9A. [Figure 10] 10A and 10B are cross-sectional views showing different configuration examples of adjacent stacked structure light-emitting elements. [Figure 11A] 1 shows a plan view of a part of a stack structure light emitting element array. [Figure 11B] 11B is a schematic diagram showing a part of the cross-sectional structure taken along the line XIB-XIB in FIG. 11A. [Figure 11C]11B is a schematic diagram showing a part of the cross-sectional structure taken along the XIC-XIC cutting line in FIG. 11A. [Figure 12] 1 is a cross-sectional view showing an example of the configuration of adjacent stacked light-emitting elements. FIG. [Figure 13] 13 is a plan view showing an example of the layout of the stacked light emitting element shown in FIG. 12 that emits red, green or blue light. FIG. [Figure 14] Another example of the structure of the stacked light emitting device is shown. [Figure 15] 1A and 1B show schematic diagrams of exemplary configurations of a vehicle and an in-vehicle display. [Figure 16] 1 shows a schematic configuration example of a smartphone. [Figure 17] 1 shows an example of a biosensor to which an OLED light-emitting device according to an embodiment of the present specification is applied. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the accompanying drawings. The embodiments are merely examples for realizing the present disclosure and do not limit the technical scope of the present disclosure. The same reference symbols are used for common components in each drawing. For clarity of explanation, the dimensions and shapes of the illustrated objects may be exaggerated.

[0011] An OLED (Organic Light-Emitting Diode) light-emitting device is disclosed below. A representative example of an OLED light-emitting device is an OLED display device. An OLED display device according to an embodiment of the present specification includes a stacked light-emitting element in which multiple light-emitting units, each having an OLED structure, are stacked. In one stacked light-emitting element, the multiple stacked light-emitting units include light-emitting layers of the same color or different colors. Unless otherwise specified, in this specification, a pixel is an element that emits a specific color to display an image, for example, red, blue, green, or white light. Note that red, blue, or green pixels may be referred to as subpixels. A stacked light-emitting element corresponds to one pixel.

[0012] In a stacked-structure light-emitting element, a charge-generating layer that generates charge when a voltage is applied is sandwiched between adjacent upper and lower light-emitting units. The charge-generating layer supplies electrons to one light-emitting unit and holes to the other unit. If charge leakage occurs between the charge-generating layers of adjacent stacked-structure light-emitting elements, this minute current can cause adjacent pixels to emit light slightly (so-called crosstalk). In this embodiment, we will describe an OLED display device structure that reduces or eliminates this charge leakage.

[0013] The display region of an OLED display device according to an embodiment of the present specification includes stacked light-emitting elements corresponding to pixels. The stacked light-emitting elements include a plurality of stacked light-emitting units and further include a charge generation layer between the light-emitting units. The ends of the charge generation layers of adjacent stacked light-emitting elements overlap on the top surface of the pixel definition layer. The pixel definition layer is an example of an element isolation layer. In the overlapping portions of the charge generation layer ends, the ends of the constituent layers that generate charges of the same polarity in each charge generation layer are interposed between the constituent layers that generate charges of the same polarity. This makes it possible to suppress charge leakage between the charge generation layers.

[0014] [Device configuration] 1 schematically shows an example of the configuration of an OLED display device 1. The OLED display device 1 includes a TFT (Thin Film Transistor) substrate 10 on which OLED elements and pixel circuits are formed, and a thin film encapsulation (TFE) structure 20 that encapsulates the organic light-emitting elements. The thin film encapsulation structure 20 is one type of encapsulation structure, and as another example, the encapsulation structure may include a encapsulation substrate that encapsulates the organic light-emitting elements and a bonding portion (glass frit seal portion) that bonds the TFT substrate 10 and the encapsulation substrate. Dry nitrogen, for example, is sealed between the TFT substrate 10 and the encapsulation substrate.

[0015] A scan driver 31, an emission driver 32, a protection circuit 33, a driver IC 34, and a demultiplexer 36 are arranged around the cathode electrode formation region 14 outside the display region 25 of the TFT substrate 10. The driver IC 34 is connected to external devices via an FPC (Flexible Printed Circuit) 35. The scan driver 31, the emission driver 32, and the protection circuit 33 are peripheral circuits formed on the TFT substrate 10.

[0016] The scan driver 31 drives the scan lines of the TFT substrate 10. The emission driver 32 drives the emission control lines to control the light emitting period of each pixel. The driver IC 34 is implemented using, for example, an anisotropic conductive film (ACF).

[0017] The protection circuit 33 prevents electrostatic damage to elements in the pixel circuit. The driver IC 34 provides power and timing signals (control signals) to the scan driver 31 and the emission driver 32. Furthermore, the driver IC 34 provides power and data signals to the demultiplexer 36.

[0018] The demultiplexer 36 sequentially outputs the output of one pin of the driver IC 34 to d data lines (d is an integer equal to or greater than 2). The demultiplexer 36 switches the output data line of the data signal from the driver IC 34 d times within a scanning period, thereby driving d times as many data lines as the number of output pins of the driver IC 34.

[0019] [Configuration of stacked light-emitting element] FIG. 2A shows a plan view of a portion of a stacked light-emitting element array. FIG. 2A shows an example layout of multiple stacked light-emitting elements in a display area 25. In the example configuration of FIG. 2A, each stacked light-emitting element emits white light. For example, a color filter (not shown) may be formed in front of the stacked light-emitting element, allowing each pixel to emit red, blue, or green light. In another example configuration, each stacked light-emitting element may emit red, blue, or green light. The red, blue, and green pixels display information for one pixel in a video frame.

[0020] In Fig. 2A, the light-emitting regions 251 of the stacked structure light-emitting element are rectangular with rounded corners, and are arranged in a matrix. Of the light-emitting regions of the stacked structure light-emitting element in Fig. 2A, only one light-emitting region is indicated by the reference numeral 251 as an example. The shape and layout of the light-emitting regions of the stacked structure light-emitting element are arbitrary.

[0021] Each light-emitting region 251 is surrounded by an insulating pixel definition layer 253. The pixel definition layer 253 defines each pixel (light-emitting region 251). The light-emitting regions 251 are formed within openings 254 in the pixel definition layer 253. In FIG. 2A , one opening is shown by reference numeral 254 as an example. The area between the openings 254 is the top surface of the pixel definition layer 253.

[0022] As will be described below, light-emitting region 251 is the region of the anode electrode exposed at the bottom of opening 254. In the example of Figure 2A, the wall surfaces defining the opening in pixel defining layer 253 have a tapered shape, with the area of ​​the opening decreasing towards the bottom.

[0023] 2B is a schematic cross-sectional view taken along the line IIB-IIB in FIG. 2A. FIG. 2B shows a stacked structure of adjacent stacked light-emitting elements 210A and 210B. The stacked light-emitting elements 210A and 210B are each disposed on an anode electrode exposed through an opening 254 in a pixel definition layer 253. The stacked light-emitting elements 210A and 210B each include a plurality of stacked light-emitting units and a charge generation layer between the light-emitting units.

[0024] In the example shown in FIG. 2B , the stacked light-emitting units of each of the stacked light-emitting elements 210A and 210B are composed of two light-emitting units. An upper light-emitting unit 280 is stacked on top of a lower light-emitting unit 270. In FIG. 2B , one upper light-emitting unit and one lower light-emitting unit are indicated by reference numerals as examples. The lower light-emitting unit 270 and the upper light-emitting unit 280 may emit different colors, such as blue light and yellow-green light. The lower light-emitting unit 270 and the upper light-emitting unit 280 may each emit the same white light.

[0025] A charge generation layer is present between the upper light-emitting unit 280 and the lower light-emitting unit 270. The charge generation layers 291A and 291B of the stacked structure light-emitting elements 210A and 210B form interfaces with the upper light-emitting unit 280 and the lower light-emitting unit 270, respectively. The charge generation layers 291A and 291B are composed of two constituent layers (charge generation constituent layers). The configurations of the charge generation layers 291A and 291B will be described in detail later.

[0026] The stacked light-emitting element 210A is an example of a first stacked light-emitting element. Its lower light-emitting unit 270, charge generation layer 291A, and upper light-emitting unit 280 are examples of a first light-emitting unit, a first charge generation layer, and a second light-emitting unit, respectively. The stacked light-emitting element 210B is an example of a second stacked light-emitting element. Its lower light-emitting unit 270, charge generation layer 291B, and upper light-emitting unit 280 are examples of a third light-emitting unit, a second charge generation layer, and a fourth light-emitting unit, respectively.

[0027] As shown in FIG. 2B, the OLED display device 1 includes a TFT circuit layer (TFT array) 260 and a plurality of separated lower electrodes, such as anode electrodes 261, disposed on an insulating substrate. The anode electrodes 261 reflect light from the light-emitting units. The OLED display device 1 further includes an upper electrode, such as a cathode electrode 262. The cathode electrodes 262 transmit light from the light-emitting units. For example, the cathode electrodes 262 of each pixel are part of a single electrode film. Note that the positional relationship between the anode electrodes and the cathode electrodes may be reversed. In this configuration, the polarities of each layer are reversed.

[0028] The insulating substrate is made of, for example, glass or resin, and may be a rigid or flexible substrate. The side closer to the insulating substrate is referred to as the lower side, and the side farther from it is referred to as the upper side. Each stacked structure light-emitting element is disposed between a cathode electrode 262 and an anode electrode 261. Multiple anode electrodes 261 are disposed on the surface of the TFT circuit layer 260 (for example, on a planarization film), and one stacked structure light-emitting element is disposed on one anode electrode 261.

[0029] The cathode electrode 262 is a transparent electrode (including semi-transparent electrodes) that transmits some or all of the visible light from the organic light-emitting layer toward the sealing structure. The cathode electrode 262 for each pixel is a different part of a continuous sheet-like conductive film. A cap layer (not shown) may be formed on the cathode electrode 262.

[0030] The TFT circuit layer 260 includes a plurality of pixel circuits, each including a plurality of TFTs. Each pixel circuit is formed between an insulating substrate and an anode electrode 261 and controls the current supplied to each anode electrode 261. The anode electrode 261 is connected to the pixel circuit via a contact portion formed in a contact hole in a planarization film (not shown). Pixel circuits of any configuration can be used. An example of a pixel circuit includes, for example, a pixel selection switch TFT, a drive TFT for an OLED element, a switch TFT that controls the supply and stop of drive current to the OLED element, and a storage capacitor.

[0031] The pixel definition layer 253 is formed to cover the periphery of each anode electrode 261. A portion of the anode electrode 261, including its center, is present within an opening 254 of the pixel definition layer 253 (is exposed at the opening 254). The area within the opening 254 of the anode electrode 261 corresponds to the light-emitting area 251. A stacked structure light-emitting element is stacked on the area within the opening 254 of the anode electrode 261.

[0032] The lower light-emitting unit 270 includes a hole transport layer 271, an emissive layer 272, and an electron transport layer 273. The hole transport layer 271, the emissive layer 272, and the electron transport layer 273 are stacked in this order from the bottom up. In the configuration example of FIG. 2B , the hole transport layer 271 contacts the anode electrode 261 to form an interface. In this example, the emissive layer 272 emits blue light. These layers may be formed of any appropriate materials.

[0033] 2B , the hole transport layer 271, the light-emitting layer 272, and the electron transport layer 273 are each part of a continuous film including the corresponding layers of the plurality of lower light-emitting units 270. The hole transport layer 271 and / or the electron transport layer 273 may be omitted. The lower light-emitting unit 270 may have other stacked structures. Other functional layers, such as a hole injection layer, may be stacked between the anode electrode 261 and the hole transport layer 271.

[0034] The upper light-emitting unit 280 includes a hole transport layer 281, an emissive layer 282, and an electron transport layer 283. The hole transport layer 281, the emissive layer 282, and the electron transport layer 283 are stacked in this order from the bottom up. In the configuration example of FIG. 2B , the electron transport layer 283 contacts the cathode electrode 262 to form an interface. In this example, the emissive layer 282 emits yellow-green light. These layers may be formed of any appropriate materials.

[0035] 2B , the hole transport layer 281, the light-emitting layer 282, and the electron transport layer 283 are each part of a continuous film including the corresponding layers of the plurality of upper light-emitting units 280. The hole transport layer 281 and / or the electron transport layer 283 may be omitted. The upper light-emitting unit 280 may have other stacked structures. Other functional layers, such as an electron injection layer, may be stacked between the cathode electrode 262 and the electron transport layer 283.

[0036] The charge generation layers 291A and 291B are respectively stacked between the lower light-emitting unit 270 and the upper light-emitting unit 280. The charge generation layers 291A and 291B are in contact with the electron transport layer 273 of the lower light-emitting unit 270 and the hole transport layer 281 of the upper light-emitting unit 280 to form interfaces.

[0037] As described below, the charge generation layer can be composed of a single layer or multiple layers. The charge generation layer can be composed of an electron generation layer that generates only electrons, a hole generation layer that generates only holes, or an electron / hole generation layer that generates both electrons and holes. Various materials are known that can be used for each of these layers, and any of these materials may be used. For example, inorganic compounds such as V2O5Re2O7 and ITO, or organic compounds may be used. The thicknesses of the hole transport layers or hole injection layers of the light-emitting units of different colors may be different.

[0038] The pixel-defining layer 253 is a layer between the anode electrode 261 and the hole-transporting layer 271 of the lower light-emitting unit 270. The pixel-defining layer 253 includes side surfaces within the openings 254 where the light-emitting regions 251 of the stacked structure light-emitting elements are formed, and a top surface 256 between the openings 254. In the example of FIG. 2B , the top surface 256 is flat.

[0039] As shown in FIG. 2B , the charge generation layers 291A and 291B are separated. More specifically, the charge generation layers 291A and 291B cover the corresponding openings 254 of the pixel definition layer 253, and their respective ends are located on the top surface 256 of the pixel definition layer 253. These ends are spaced apart in the in-plane direction (the direction within the main surface of the substrate). That is, there is a gap between the ends of the charge generation layers 291A and 291B in the in-plane direction. This gap is filled with the material of the hole transport layer 281.

[0040] Figure 2C shows an enlarged view of the area enclosed by the dashed circle IIC in Figure 2B. Each of charge generation layers 291A and 291B is formed of multiple layers. Specifically, they have a two-layer structure, including a lower electron generation layer 293 and an upper hole generation layer 295.

[0041] The charge generating layers 291A and 291B have the same structure, and the materials of the electron generating layer 293 and the hole generating layer 295 are the same. In Figure 2C, the electron generating layer and the hole generating layer of the charge generating layer 291B are, for example, indicated by reference numerals 293 and 295, respectively. The electron generating layer 293 provides electrons to the lower light-emitting unit 270, and the hole generating layer 295 provides holes to the upper light-emitting unit 280.

[0042] The charge generation layers 291A and 291B are each formed to cover a portion of the top surface 256 of the pixel definition layer 253 that surrounds them. The charge generation layers 291A and 291B are formed only on a portion of the top surface 256, and the ends of the charge generation layers 291A and 291B exist on the top surface 256 of the pixel definition layer 253. The electron generation layer 293 is covered with a hole generation layer 295. The ends of the charge generation layers 291A and 291B are spaced apart in the in-plane direction, with a gap between them.

[0043] In this way, the charge generation layers 291A and 291B are separated, thereby suppressing leakage current between them. In addition, since the ends of the charge generation layers 291A and 291B are located on the top surface 256 of the pixel definition layer 253, charges can be more appropriately supplied to the upper and lower light-emitting units of the stacked structure light-emitting element.

[0044] The ends of the charge generating layer 291A and the charge generating layer 291B have tapered shapes on the top surface 256 of the pixel defining layer 253. The ends of the electron generating layer 293 and the hole generating layer 295 also have tapered shapes. By tapering the charge generating layers, even if the layers overlap due to misalignment during film formation, the film thickness is thin, so that leak paths can be blocked.

[0045] In the configuration example shown in Figures 2A and 2B, adjacent stacked light-emitting elements include light-emitting layers of the same color in the lower and upper light-emitting units, respectively, and the light-emitting layers of adjacent lower and upper light-emitting units are contiguous. The colors of the light-emitting layers of the lower and upper light-emitting units are different. In another configuration example, adjacent stacked light-emitting elements can include light-emitting layers of different colors. For example, one stacked light-emitting element can emit red, blue, or green light, and the other stacked light-emitting element can emit light of a different color within those colors. In this configuration, the light-emitting layers of different colors of adjacent lower and upper light-emitting units are separated in the in-plane direction, as are the charge-generating layers shown in Figures 2A and 2B.

[0046] 3A is a cross-sectional view showing a different configuration example of charge generation layers 291A and 291B of adjacent stacked light-emitting elements 210A and 210B. The following mainly describes the differences from the configuration example shown in FIG. 2B. In the configuration example shown in FIG. 3A, the ends of charge generation layers 291A and 291B overlap on top surface 256 of pixel defining layer 253. This configuration eliminates the need for an air gap to separate adjacent stacked light-emitting elements, thereby facilitating the development of higher-definition OLED displays.

[0047] Figure 3B shows an enlarged view of the area surrounded by the dashed circle IIIB in Figure 3A. Charge generation layers 291A and 291B each have a two-layer structure. Charge generation layer 291A is composed of a lower electron generation layer 293A and an upper hole generation layer 295A. Charge generation layer 291B is composed of a lower electron generation layer 293B and an upper hole generation layer 295B.

[0048] An end portion of the charge generating layer 291B is stacked on an end portion of the charge generating layer 291A. Specifically, an end portion of the electron generating layer 293B is stacked on an end portion of the hole generating layer 295A of the charge generating layer 291A. These are in contact with each other to form an interface. The stacked structure of these ends is composed of the electron generating layer 293A, the hole generating layer 295A, the electron generating layer 293B, and the hole generating layer 295B stacked in this order from the bottom.

[0049] The ends of the charge generating layer 291A and the charge generating layer 291B have tapered shapes on the top surface 256 of the pixel defining layer 253. The ends of the electron generating layer 293A and the hole generating layer 295A have tapered shapes. The ends of the electron generating layer 293B and the hole generating layer 295B have tapered shapes. Tapering the charge generating layers makes it possible to block leak paths.

[0050] A hole generating layer 295A is present between the electron generating layer 293A of the charge generating layer 291A and the electron generating layer 293B of the charge generating layer 291B. The hole generating layer 295A contacts the electron generating layer 293A and the electron generating layer 293B to form an interface. The electron generating layer 293A and the electron generating layer 293B are not in direct contact with each other but are separated by the hole generating layer 295A.

[0051] An electron generating layer 293B is present between the hole generating layer 295A of the charge generating layer 291A and the hole generating layer 295B of the charge generating layer 291B. The electron generating layer 293B contacts the hole generating layer 295A and the hole generating layer 295B, respectively, to form an interface. The hole generating layer 295A and the hole generating layer 295B are not in direct contact with each other but are separated by the electron generating layer 293B.

[0052] The electron generating layers 293A and 293B supply and transport electrons and block holes without allowing them to flow. On the other hand, the hole generating layers 295A and 295B supply and transport holes and block electrons without allowing them to flow. In other words, the electron generating layers 293A and 293B only allow electrons to flow out of the two polarities of charges, and the hole generating layers 295A and 295B only allow holes to flow out of the two polarities of charges.

[0053] As described above, in the overlapping portion of the adjacent charge generation layers, the end of the component layer of the charge generation layer 291A or 291B that generates only charges of the other polarity and blocks the charges of one polarity is interposed between the charge generation component layers that generate charges of one polarity in the charge generation layer 291A and the charge generation layer 291B, respectively, thereby effectively suppressing charge leakage between the charge generation layers.

[0054] [Film formation method using a metal mask] The charge generation layer having the structure described with reference to Figures 2A to 3B can be formed, for example, by vapor deposition using a metal mask with a predetermined opening pattern. The material is vaporized by heating the material in the vapor deposition source while moving the vapor deposition source. The heated material vaporizes and is ejected to the outside from the vapor deposition source's ejection port. The ejected material passes through the openings of a metal mask aligned between the vapor deposition source and the target substrate, and is deposited at predetermined locations on the target substrate to form a film.

[0055] Figure 4 shows a schematic diagram of a metal mask opening pattern that can be used to create a charge generating layer, showing two opening patterns when one metal mask is aligned at two different positions.

[0056] A dashed rectangle 301 with rounded corners schematically shows the opening pattern of a metal mask aligned at a first position. In FIG. 4, one dashed rectangle with rounded corners is indicated by reference numeral 301 as an example. A dotted rectangle 303 with rounded corners schematically shows the opening pattern of a metal mask aligned at a second position different from the first position. In FIG. 4, one dotted rectangle with rounded corners is indicated by reference numeral 303 as an example.

[0057] The metal mask shown in Figure 4 is used for vapor deposition of one of the constituent layers of the charge generating layer, such as the hole generating layer or the electron generating layer. Each constituent layer can be formed by vapor deposition in a different chamber using the method described below.

[0058] In one embodiment of the present specification, each constituent layer of the charge generating layer is formed by two deposition processes using a single metal mask aligned at different positions in sequence, thereby making it possible to form the electron generating layer and the hole generating layer of the charge generating layer having the structure shown in FIG. 3A without preparing two chambers.

[0059] In the configuration example shown in Fig. 4, the openings in the metal mask are laid out in a staggered arrangement. That is, the opening pattern has opening rows, each consisting of openings aligned along the X axis (in the left-right direction in Fig. 4), arranged along the Y axis (in the up-down direction in Fig. 4). The center of gravity of one opening in adjacent opening rows is shifted from the center of gravity of the other opening along the Y axis by half a pitch.

[0060] The constituent layers of the charge generating layer are formed, for example, by evaporating a material with a metal mask aligned at a first position, then shifting the metal mask to align it at a second position, and evaporating the same material.

[0061] 4, openings 301 and 302 are alternately arranged along the X axis, and openings 301 and 302 are alternately arranged along the Y axis. Apertures 301 and 303 adjacent to each other along the X axis partially overlap. On the other hand, openings 301 and 303 adjacent to each other along the Y axis are spaced apart, with no overlapping portions. Therefore, the ends of the charge generation layers of stacked light-emitting elements adjacent to each other along the X axis are stacked, and the ends of the charge generation layers of stacked light-emitting elements adjacent to each other along the Y axis are spaced apart.

[0062] For example, the cross-sectional structure of the portion shown along the AA line in Fig. 4 has the cross-sectional structure shown in Fig. 3A, while the cross-sectional structure of the portion shown along the BB line in Fig. 4 has the cross-sectional structure shown in Fig. 2B.

[0063] Figure 5 shows another example of an opening pattern of a metal mask that can be used to create a charge generating layer. Figure 5 shows two opening patterns when one metal mask is aligned at two different positions.

[0064] A dashed rectangle 305 with rounded corners schematically shows the opening pattern of a metal mask aligned at a first position. In FIG. 5, one dashed rectangle with rounded corners is indicated by reference numeral 305 as an example. A dotted rectangle 307 with rounded corners schematically shows the opening pattern of a metal mask aligned at a second position different from the first position. In FIG. 5, one dotted rectangle with rounded corners is indicated by reference numeral 307 as an example.

[0065] The opening pattern of the metal mask shown in Fig. 5 is a staggered arrangement, similar to the configuration example of Fig. 4. In the example shown in Fig. 5, openings 305 and openings 307 are alternately arranged along the X axis, and openings 305 and openings 307 are alternately arranged along the Y axis.

[0066] In some pairs of apertures 305 and 307 adjacent along the X axis, the apertures partially overlap. In other pairs of apertures 305 and 307 adjacent along the X axis, the apertures are spaced apart and do not overlap. Furthermore, in some pairs of apertures 305 and 307 adjacent along the Y axis, the apertures partially overlap. In other pairs of apertures 305 and 307 adjacent along the Y axis, the apertures are spaced apart and do not overlap.

[0067] Thus, there are stacked structure light-emitting element pairs in which the ends of the charge generation layers are stacked, and stacked structure light-emitting element pairs in which the ends of the charge generation layers are separated. In the configuration example of Figure 5, each opening 305 partially overlaps with one (left) opening 307 adjacent to it along the X axis and is separated from the other (right) opening 307. Also, each opening 305 partially overlaps with one (upper) opening 307 adjacent to it along the Y axis and is separated from the other (lower) opening 307.

[0068] For example, the cross-sectional structures of the portions indicated by the CC and EE cutting lines in Fig. 5 have the cross-sectional structures shown in Fig. 3A. The cross-sectional structures of the portions indicated by the DD and FF cutting lines in Fig. 5 have the cross-sectional structures shown in Fig. 2B.

[0069] 4 and 5, the charge generation layers of adjacent stacked light-emitting elements may have different structures in different directions. In other configuration examples, the ends of the charge generation layers of each stacked light-emitting element may be spaced apart from or overlap with the ends of the charge generation layers of all adjacent stacked light-emitting elements along the X-axis and Y-axis.

[0070] [OLED display manufacturing method] An example of a method for manufacturing the OLED display device 1 will be described. In the following description, elements formed in the same step (simultaneously) are elements of the same layer. In manufacturing the OLED display device 1, first, a TFT circuit layer 260 is formed on an insulating substrate. The TFT circuit layer 260 can be formed using a known technique, and detailed description thereof will be omitted.

[0071] Next, an anode electrode is formed on the TFT circuit layer 260. For example, the anode electrode 261 is formed by sputtering on a planarization film in which contact holes have been formed. The layer structure and material of the anode electrode 261 are arbitrary. For example, it can be formed by vapor deposition or sputtering of a metal material. The anode electrode 261 is connected to the pixel circuit in the TFT circuit layer 260 via a contact portion.

[0072] Next, for example, a photosensitive organic resin film is deposited by spin coating or the like, and patterned to form pixel definition layer 253. By patterning, openings 254 are formed in pixel definition layer 253, and anode electrode 261 of each pixel is exposed through the formed openings 254. The pixel definition layer 253 separates the light-emitting regions.

[0073] A part of the manufacturing process after forming the pixel definition layer 253 will be described with reference to the flowchart in Fig. 6. A hole transport layer 271, a light-emitting layer 272, and an electron transport layer 273 are formed in this order over the entire display area on which the pixel definition layer 253 has been formed (S101). These layers can be formed by, for example, vapor deposition.

[0074] Next, the material for the electron generating layer is deposited on the substrate by vapor deposition using a metal mask corresponding to the pattern of the electron generating layers 293A and 293B, thereby forming the electron generating layer 293A (S102). The electron generating layer 293A is formed by the method described with reference to FIG. 4 or 5.

[0075] Next, the material for the hole generating layers 295A and 295B is deposited on the substrate by vapor deposition using a metal mask corresponding to the pattern of the hole generating layers 295A and 295B to form the hole generating layer 295A (S103). The hole generating layer 295A is formed by the method described with reference to FIG. 4 or 5.

[0076] Next, the material for the electron generating layer is deposited on the substrate by vapor deposition using a metal mask corresponding to the pattern of the electron generating layers 293A and 293B, thereby forming the electron generating layer 293B (S104). The electron generating layer 293B is formed by the method described with reference to FIG. 4 or 5.

[0077] Next, the material for the hole generating layer is attached to the substrate by vapor deposition through a metal mask corresponding to the pattern of the hole generating layers 295A and 295B to form the hole generating layer 295B (S105). The hole generating layer 295B is formed by the method described with reference to FIG. 4 or 5.

[0078] Next, a hole transport layer 281, a light emitting layer 282, and an electron transport layer 283 are formed in this order over the entire display area (S106). These layers can be formed by, for example, vapor deposition. Next, a metal material for the cathode electrode 262 is deposited (S107). The cathode electrode 262 is formed over the entire display area. The layer configuration and material of the cathode electrode 262 are arbitrary. For example, it can be formed by vapor deposition or sputtering of a metal material. After the cathode electrode 262 is formed, a color filter layer and a sealing structure are formed.

[0079] The above manufacturing method is merely an example, and the OLED display device can be manufactured by other manufacturing methods. For example, if the OLED display device displays an image using red, blue, and green stacked light-emitting elements, the light-emitting layers of these colors can be formed by evaporation using corresponding metal masks. In this configuration, color filters are omitted.

[0080] [Other configuration examples of stacked structure light emitting devices] Other configuration examples of the stacked structure light-emitting element will be described below. Differences from the configuration example described with reference to Fig. 3A will be mainly described. Fig. 7A is a cross-sectional view showing a different configuration example of adjacent stacked structure light-emitting elements 210A and 210B. Fig. 7B shows an enlarged view of the portion surrounded by the dashed circle VIIB in Fig. 7A.

[0081] The configuration example shown in Figure 7A includes charge generation layers 351A and 351B instead of charge generation layers 291A and 291B shown in Figure 3A. Ends of charge generation layer 351A and charge generation layer 351B overlap on top surface 256 of pixel defining layer 253. This configuration can further promote higher definition OLED display devices.

[0082] Charge generation layers 351A and 351B each have a two-layer structure and are composed of two constituent layers. Specifically, charge generation layer 351A is composed of a lower electron-hole generation layer 353A and an upper hole-generation layer 355A. Similarly, charge generation layer 351B is composed of a lower electron-hole generation layer 353B and an upper hole-generation layer 355B. Electron-hole generation layers 353A and 353B are formed, for example, from an alkali metal compound or an alkaline earth metal compound, and are capable of supplying and transporting both electron and hole charges (carriers). Hole generation layers 355A and 355B are capable of supplying and transporting only holes.

[0083] As shown in FIG. 7B , an end of the charge generation layer 351B is stacked on an end of the charge generation layer 351A. The end of the charge generation layer 351A is stacked on an end of the electron transport layer 273A of the lower light-emitting unit of the stacked structure light-emitting element 210A. The end of the charge generation layer 351A and the end of the charge generation layer 351B have tapered shapes on the top surface 256 of the pixel defining layer 253. The end of the electron hole generation layer 353A and the end of the hole generation layer 355A have tapered shapes. The end of the electron hole generation layer 353B and the end of the hole generation layer 355B have tapered shapes. The tapered charge generation layers can block leak paths.

[0084] An end of the electron transport layer 273B of the lower light-emitting unit of the stacked structure light-emitting element 210B is interposed between an end of the charge generation layer 351A and an end of the charge generation layer 351B. The end of the charge generation layer 351B is stacked on an end of the charge generation layer 351A via the end of the electron transport layer 273B. The end of the electron transport layer 273B contacts the ends of the charge generation layers 351A and 351B to form interfaces.

[0085] The stacked structure at the end of the charge generating layer is composed of, from the bottom up, an electron hole generating layer 353A, a hole generating layer 355A, an electron transport layer 273B, an electron hole generating layer 353B, and a hole generating layer 355B.

[0086] An electron transport layer 273B is present between the hole generating layer 355A of the charge generating layer 351A and the electron hole generating layer 353B of the charge generating layer 351B. The electron transport layer 273B contacts the hole generating layer 355A and the electron hole generating layer 353B to form an interface. The hole generating layer 355A and the electron hole generating layer 353B are not in direct contact with each other but are separated by the electron transport layer 273B.

[0087] The electron transport layer 273B allows electrons to flow and blocks holes, so that the electron transport layer 273B can block the flow of holes between the electron-hole generating layer 353B and the hole generating layer 355A.

[0088] Between the electron transport layer 273B and the electron hole generating layer 353A of the charge generating layer 351A, there is a hole generating layer 355A of the charge generating layer 351A. The hole generating layer 355A contacts the electron hole generating layer 353A and the electron transport layer 273B to form an interface. The electron transport layer 273B and the electron hole generating layer 353A are not in direct contact with each other but are separated by the hole generating layer 355A. Therefore, the electron hole generating layer 353A of the charge generating layer 351A and the electron hole generating layer 353B of the charge generating layer 351B are not in direct contact with each other but are separated by the electron transport layer 273B and the hole generating layer 355A.

[0089] Electron transport layer 273B allows electrons to flow but blocks holes, and hole generation layer 355A blocks the flow of electrons. These layers can block the flow of electrons and holes between electron-hole generation layer 353B and electron-hole generation layer 353A.

[0090] An electron transport layer 273B is present between the hole generating layer 355A of the charge generating layer 351A and the hole generating layer 355B of the charge generating layer 351B. The electron transport layer 273B contacts the hole generating layer 355A and the electron hole generating layer 353B, respectively, to form an interface. The hole generating layer 355A and the electron hole generating layer 353B are not in direct contact with each other but are separated by the electron transport layer 273B. The electron transport layer 273B can block the flow of holes between the hole generating layer 355A and the hole generating layer 355B.

[0091] As described with reference to FIGS. 7A and 7B, an end portion of the electron transport layer 273B, which blocks holes, is interposed between the charge generation constituent layers 355A and 353B, which generate holes in the charge generation layer 351A and the charge generation layer 351B, respectively. The electron transport layer 273B is a constituent layer of the light-emitting unit of the stacked structure light-emitting element 210B. Also, as described with reference to FIGS. 7A and 7B, the electron hole generating layers 353A and 353B generate holes and electrons. In addition to the end portion of the electron transport layer 273B, which blocks holes, an end portion of the hole generating layer 355A, which blocks electrons, is interposed between the electron hole generating layers 353A and 353B.

[0092] As described above, the configuration examples shown in FIGS. 7A and 7B can effectively suppress charge leakage in the stacked portions at the ends of adjacent charge generating layers.

[0093] The stacked structure shown in Figures 7A and 7B can be formed by coating the electron transport layer and charge generation layer of the lower light-emitting unit with different colors. For example, as described in the formation of the charge generation layer, electron transport layers 273A and 273B are formed by aligning metal masks at two different positions using an alignment function. The electron transport layer 273A, charge generation layer 351A, electron transport layer 273B, and charge generation layer 351B are formed in this order. Aligning the common metal mask allows for efficient production of OLED display devices.

[0094] Fig. 8A is a cross-sectional view showing a different configuration example of adjacent stacked structure light emitting devices 210A and 210B, and Fig. 8B is an enlarged view of the portion surrounded by the dashed circle VIIIB in Fig. 8A.

[0095] The configuration example shown in Figure 8A includes charge generation layers 371A and 371B instead of charge generation layers 291A and 291B shown in Figure 3A. Ends of charge generation layer 371A and charge generation layer 371B overlap on top surface 256 of pixel defining layer 253. This configuration can further promote higher definition OLED display devices.

[0096] Each of the charge generation layers 371A and 371B has a single-layer structure and is composed of a single constituent layer. The charge generation layers 371A and 371B can supply and transport charges of both polarities, electrons and holes. The charge generation layers 371A and 371B can be formed of, for example, ITO, VO, or the like.

[0097] As shown in FIG. 8B, an end of the charge generation layer 371B is stacked on an end of the charge generation layer 371A. The end of the charge generation layer 371A is stacked on an end of the electron transport layer 273A of the lower light-emitting unit of the stacked structure light-emitting element 210A. The ends of the charge generation layers 371A and 371B have tapered shapes on the top surface 256 of the pixel definition layer 253. Tapered charge generation layers can block leakage paths.

[0098] An end of the hole transport layer 281A of the upper light-emitting unit of the stacked structure light-emitting element 210A and an end of the electron transport layer 273B of the lower light-emitting unit of the stacked structure light-emitting element 210B are interposed between an end of the charge generation layer 371A and an end of the charge generation layer 371B. The end of the charge generation layer 371B is stacked on the end of the charge generation layer 371A, with the end of the hole transport layer 281A and the end of the electron transport layer 273B interposed therebetween.

[0099] The edge of the hole transport layer 281A contacts the edge of the charge generation layer 371A and the edge of the electron transport layer 273B to form an interface. The edge of the electron transport layer 273B contacts the edge of the hole transport layer 281A and the edge of the charge generation layer 371B to form an interface.

[0100] The laminated structure at the end of the charge generation layer is composed of, from the bottom, a charge generation layer 371A, a hole transport layer 281A, an electron transport layer 273B, and a charge generation layer 371B.

[0101] A hole transport layer 281A and an electron transport layer 273B are present between the charge generation layer 371A and the charge generation layer 371B. The charge generation layer 371A and the electron transport layer 273B are not in direct contact with each other and are separated by the hole transport layer 281A. The hole transport layer 281A and the charge generation layer 371B are not in direct contact with each other and are separated by the electron transport layer 273B. In other words, the charge generation layer 371A and the charge generation layer 371B are not in direct contact with each other and are separated by the lamination of the hole transport layer 281A and the electron transport layer 273B.

[0102] Hole transport layer 281A allows holes to flow and blocks electrons, preventing them from flowing. Electron transport layer 273B allows electrons to flow and blocks holes, preventing them from flowing. Therefore, the stack of hole transport layer 281A and electron transport layer 273B can block the flow of holes and electrons between charge generation layer 371A and charge generation layer 371B.

[0103] As described with reference to FIGS. 8A and 8B, an end of the electron transport layer 273B that blocks holes exists between the charge generation layer 371A and the charge generation layer 371B that generate holes. Alternatively, an end of the hole transport layer 281A that blocks electrons exists between the charge generation layer 371A and the charge generation layer 371B that generate electrons. Also, as described with reference to FIGS. 8A and 8B, the charge generation layer 371A and the charge generation layer 371B generate electrons and holes. In addition to an end of the electron transport layer 273B that blocks holes, an end of the hole transport layer 281A that blocks electrons exists between the charge generation layer 371A and the charge generation layer 371B.

[0104] As described above, the configuration example shown in Figures 8A and 8B can effectively suppress charge leakage at the stacked portions of adjacent charge generation layers. The stacked structure shown in Figures 8A and 8B can be formed, for example, by coating layers from the electron transport layer of the lower light-emitting unit to the hole transport layer of the upper light-emitting unit. For example, as described in the formation of the charge generation layer, hole transport layers 281A and 281B and electron transport layers 273A and 273B are formed by aligning metal masks at two different positions using an alignment function. The electron transport layer 273A, charge generation layer 371A, hole transport layer 281A, electron transport layer 273B, charge generation layer 371B, and hole transport layer 281B are formed in this order. Aligning the common metal mask allows for efficient production of OLED display devices.

[0105] FIG. 9A is a cross-sectional view showing a different configuration example of adjacent stacked light-emitting elements 210A and 210B. FIG. 9B is an enlarged view of the portion surrounded by the dashed circle IXB in FIG. 9A. The configuration example shown in FIG. 9A includes charge generation layers 381A and 381B instead of the charge generation layers 291A and 291B shown in FIG. 3A. Ends of charge generation layer 381A and charge generation layer 381B overlap on top surface 256 of pixel defining layer 253. This configuration can further promote higher definition OLED display devices.

[0106] Charge generation layer 381A is composed of a lower electron-hole generating layer 383A and an upper hole generating layer 385A. Similarly, charge generation layer 381B is composed of a lower electron-hole generating layer 383B and an upper hole generating layer 385B. Charge generation layers 381A and 381B may have different structures. For example, they may have the layer structures shown in Figures 3B, 7B, or 8B.

[0107] 9B, an end portion of the charge generation layer 381B is stacked on an end portion of the charge generation layer 381A. An end portion of the hole transport layer 281A of the upper light-emitting unit of the stack structure light-emitting element 210A and an end portion of the light-emitting layer 282A of the same light-emitting unit are interposed between the end portions of the charge generation layer 381A and the charge generation layer 381B. The end portion of the charge generation layer 381B is stacked on the end portion of the charge generation layer 381A, with the end portions of the hole transport layer 281A and the light-emitting layer 282A interposed therebetween.

[0108] The ends of the charge generating layer 381A and the charge generating layer 381B have tapered shapes on the top surface 256 of the pixel defining layer 253. The ends of the electron hole generating layer 383A and the hole generating layer 385A have tapered shapes. The ends of the electron hole generating layer 383B and the hole generating layer 385B have tapered shapes. Tapering the charge generating layers makes it possible to block leak paths.

[0109] An edge of the hole transport layer 281A contacts an edge of the hole generating layer 385A of the charge generating layer 381A and an edge of the light emitting layer 282A to form an interface. An edge of the light emitting layer 282A contacts an edge of the hole transport layer 281A and an edge of the electron hole generating layer 383B of the charge generating layer 381B to form an interface.

[0110] The stacked structure at the end of the charge generating layer is composed of, from the bottom up, an electron hole generating layer 383A, a hole generating layer 385A, a hole transport layer 281A, an emissive layer 282A, an electron hole generating layer 383B, and a hole generating layer 385B.

[0111] The light-emitting layer 282A is present between the hole transport layer 281A and the electron-hole generating layer 383B of the charge generating layer 381B. The hole transport layer 281A and the electron-hole generating layer 383B are not in direct contact with each other but are separated by the light-emitting layer 282A. Focusing on the relationship between the charge generating layers 381A and 381B, the light-emitting layer 282A is interposed between them, and they are separated by the light-emitting layer without being in direct contact with each other.

[0112] The light-emitting layer has a lower mobility than other layers. For example, the mobility of holes in the hole transport layer is 10 -4 cm 2 / Vs, whereas the hole mobility in the emissive layer is about 10 -11 cm 2 / Vs. Therefore, the light emitting layer 282A can effectively suppress charge leakage in the stacked structure at the end of the adjacent charge generating layer.

[0113] As described above, in the configuration examples shown in FIGS. 9A and 9B, the light-emitting layer 282A is interposed between the charge generation layer 381A and the charge generation layer 381B in the area where the ends of the adjacent charge generation layers overlap. This effectively prevents charge leakage between the charge generation layers 381A and 381B. In the configuration example of FIG. 9B, the end of the light-emitting layer 282A is separated from the end of the charge generation layer 381A by the end of the hole transport layer 281A without directly contacting the end of the charge generation layer 381A. In other configuration examples, a portion of the end of the light-emitting layer 282A may be in contact with a portion of the end of the charge generation layer 381A.

[0114] As shown in FIG. 9B, the ends of the hole transport layer 281B and the light-emitting layer 282B of the upper light-emitting unit of the stacked light-emitting element 210B are stacked on the ends of the charge generation layer 381B. The stacked structure shown in FIGS. 9A and 9B can be formed by coating layers from the charge generation layer to the light-emitting layer of the upper light-emitting unit with different coatings. For example, as described in the formation of the charge generation layer, the hole transport layer and the light-emitting layer are formed by aligning metal masks at two different positions using an alignment function. The charge generation layer 381A, the hole transport layer 281A, the light-emitting layer 282A, the charge generation layer 381B, the hole transport layer 281B, and the light-emitting layer 282B are formed in this order. Aligning the common metal mask allows for efficient production of OLED display devices.

[0115] Another example of a stacked structure light-emitting element will now be described. Fig. 10 is a cross-sectional view showing a different configuration example of adjacent stacked structure light-emitting elements 210A and 210B. The differences from the configuration example shown in Fig. 2B will be mainly described. In the configuration example shown in Fig. 10, the end of the hole transport layer of the lower light-emitting unit and the end of the hole transport layer of the upper light-emitting unit are located on the top surface of the pixel defining layer.

[0116] In FIG. 10, a dashed circle 510 surrounds the ends of the charge generation layer 291A and hole transport layer 511A of the stacked structure light emitting element 210A, and the ends of the charge generation layer 291B and hole transport layer 511B of the stacked structure light emitting element 210B.

[0117] The charge generation layers 291A and 291B are formed only on a portion of the top surface of the pixel definition layer 253, and the ends of the charge generation layers 291A and 291B exist on the top surface of the pixel definition layer 253. The ends of the charge generation layers 291A and 291B are spaced apart in the in-plane direction, and a gap exists between them.

[0118] The hole transport layers 511A and 511B are formed only on a portion of the top surface of the pixel definition layer 253, and the ends of the hole transport layers 511A and 511B are present on the top surface of the pixel definition layer 253. The ends of the hole transport layers 511A and 511B are separated in the in-plane direction, with a gap between them. The end of the hole transport layer 511A has a tapered shape and covers the end of the charge generation layer 291A. The end of the hole transport layer 511B has a tapered shape and covers the end of the charge generation layer 291B. In the in-plane direction, the hole transport layer 511A, the light-emitting layer 282, and the hole transport layer 511B are present between the end of the charge generation layer 291A and the end of the charge generation layer 291B.

[0119] In FIG. 10 , a dashed circle 520 surrounds the end of the hole transport layer 521A of the stacked structure light-emitting element 210A and the end of the hole transport layer 521B of the stacked structure light-emitting element 210B. The hole transport layers 521A and 521B are formed only on a portion of the top surface of the pixel definition layer 253, and the ends of the hole transport layers 521A and 521B are present on the top surface of the pixel definition layer 253. The ends of the hole transport layers 521A and 521B are separated in the in-plane direction, with a gap between them. The ends of the hole transport layers 521A and 521B have a tapered shape. In the in-plane direction, the light-emitting layer 272 is present between the end of the hole transport layer 521A and the hole transport layer 521B of the hole transport layer 521A.

[0120] Next, other structural examples of stacked structure light-emitting elements will be described. Differences from the structural examples described with reference to Figures 2A to 2C will be mainly described below. Figure 11A shows a plan view of a portion of a stacked structure light-emitting element array. Figure 11B shows a portion of the cross-sectional structure taken along line XIB-XIB in Figure 11A. Figure 11C shows a portion of the cross-sectional structure taken along line XIC-XIC in Figure 11A. Line XIB-XIB is a cutting line extending in the X direction, and line XIC-XIC is a cutting line extending in the Y direction.

[0121] 11B shows the boundary between two stacked light-emitting elements adjacent in the X direction. FIG. 11C shows the boundary between two stacked light-emitting elements adjacent in the Y direction. As shown in FIGS. 11B and 11C, the charge generation layers 291A and 291B are each formed to cover a portion of the top surface 256 of the pixel definition layer 253 that surrounds them. The charge generation layers 291A and 291B are formed only on a portion of the top surface 256, and the ends of the charge generation layers 291A and 291B exist on the top surface 256 of the pixel definition layer 253. The electron generation layer 293 is covered by the hole generation layer 295. The ends of the charge generation layers 291A and 291B are spaced apart in the in-plane direction, with a gap between them.

[0122] The ends of the charge generating layer 291A and the charge generating layer 291B have tapered shapes on the top surface of the pixel defining layer 253. The tapered charge generating layer has a thin film thickness, so that even if the films overlap due to misalignment during film formation, the leak path can be blocked. The taper in the X direction shown in FIG. 11B is steeper than the taper in the Y direction shown in FIG. 11C. More specifically, the angle of the inclined surfaces of the ends (third ends) of the hole generating layer 295 and the electron generating layer 293 in FIG. 11B (angle with respect to the plane of the pixel defining layer 253) is larger than the angle of the inclined surfaces of the ends (fourth ends) of the hole generating layer 295 and the electron generating layer 293 in FIG. 11C.

[0123] The above-described structures with different taper angles can be formed by vapor deposition of the hole generating layer 295 and the electron generating layer 293 through respective masks. The vapor deposition source ejects vaporized material from the nozzle outlet. For example, the vapor deposition source has a row of nozzles arranged in the X direction and moves in the Y direction while ejecting vaporized material.

[0124] Another example of the stacked structure light emitting element will be described. Fig. 12 is a cross-sectional view showing an example of the configuration of adjacent stacked structure light emitting elements. Differences from the example of the configuration shown in Fig. 2B will be mainly described. The stacked structure light emitting element 210R emits red light, and the stacked structure light emitting element 210G emits green light. In addition to these, a stacked structure light emitting element that emits blue light is formed in the display area.

[0125] The lower light-emitting unit 270 and the upper light-emitting unit 280 of the stacked light-emitting device 210R both emit red light. That is, the light-emitting layers 272R and 282R of the two light-emitting units of the stacked light-emitting device 210R emit red light. The lower light-emitting unit 270 and the upper light-emitting unit 280 of the stacked light-emitting device 210G both emit green light. That is, the light-emitting layers 272G and 282G of the two light-emitting units of the stacked light-emitting device 210G emit green light. The light-emitting layers of the two light-emitting units of the blue stacked light-emitting device both emit blue light.

[0126] Fig. 13 is a plan view showing an example layout of stacked-structure light-emitting elements emitting red, green, or blue light shown in Fig. 12. Fig. 13 shows a part of a stacked-structure light-emitting element array, showing an example of a stripe layout. Red, green, and blue stacked-structure light-emitting elements are cyclically arranged in the X direction, and stacked-structure light-emitting elements are arranged in the Y direction.

[0127] 11B and 11C can also be applied to this configuration example. As described above, the taper in the X direction is steeper than the taper in the Y direction. This makes it possible to effectively suppress charge leakage between stack structure elements of different colors.

[0128] Fig. 14 schematically shows another structural example of the stacked structure light-emitting element. Fig. 14 shows red, green, and blue stacked structure light-emitting elements 210R, 210G, and 210B. The structure between adjacent stacked structure light-emitting elements according to the embodiment is applied to the configuration example of Fig. 14. The red stacked structure light-emitting element 210R includes red light-emitting layers 272R and 282R, and hole transport layers 271R and 281R specific to the red stacked structure light-emitting element.

[0129] The green stacked structure light emitting element 210G includes green light emitting layers 272G and 282G and hole transport layers 271G and 281G specific to the green stacked structure light emitting element. The blue stacked structure light emitting element 210B includes blue light emitting layers 272B and 282B and hole transport layers 271B and 281B specific to the blue stacked structure light emitting element. A hole injection layer 297 is formed between the hole transport layers 271R, 271G, and 271B and the anode electrode (ITO) 261.

[0130] The stacked-structure light-emitting elements 210R, 210G, and 210G of different colors have hole transport layers with different thicknesses. Specifically, the red stacked-structure light-emitting element 210R has the largest total thickness of the hole transport layers 271R and 281R, and the blue stacked-structure light-emitting element 210B has the smallest total thickness of the hole transport layers 271B and 281B.

[0131] 14, the thickness of hole transport layer 271R is greater than that of hole transport layers 271G and 271B, and the thickness of hole transport layer 271G is greater than that of hole transport layer 271B. Furthermore, the thickness of hole transport layer 281R is greater than that of hole transport layers 281G and 281B, and the thickness of hole transport layer 281G is greater than that of hole transport layer 281B. Each light-emitting unit may include a hole injection layer not shown in FIG.

[0132] 14, the lower light-emitting units of the stacked structure light-emitting elements of different colors have different total thicknesses, and the upper light-emitting units of the stacked structure light-emitting elements of different colors have different total thicknesses, specifically, the light-emitting unit of the red stacked structure light-emitting element has the largest thickness, and the light-emitting unit of the blue stacked structure light-emitting element has the smallest thickness.

[0133] In this way, the light-emitting efficiency of the stacked-structure light-emitting element can be improved by changing the film thickness of the hole transport layer / hole injection layer (hole transport layer or hole injection layer) depending on the color of the light-emitting layer of the stacked-structure light-emitting element. To change the film thickness, a hole transport layer / hole injection layer is formed for each light-emitting layer. The charge generation layer separated between the stacked-structure light-emitting elements can suppress charge leakage between the stacked-structure light-emitting elements.

[0134] The display region described in each of the above embodiments has a top-emission pixel structure. In a top-emission pixel structure, a cathode electrode is disposed on the light-emitting side (upper side in the drawing). The cathode electrode has a shape that completely covers the entire display region. The features of the present disclosure can also be applied to an OLED display device having a bottom-emission pixel structure. A bottom-emission pixel structure has a transparent anode electrode and a reflective cathode electrode, and emits light to the outside via a TFT substrate.

[0135] [Application example]

[0063] The following describes application examples of the OLED light-emitting device according to the embodiment of the present specification. Fig. 15 is a schematic diagram showing an example of an in-vehicle display using the display device according to the embodiment. Fig. 15 shows an example of the configuration of an automobile 400 equipped with the in-vehicle display according to the embodiment and in-vehicle displays 410A to 410D.

[0136] The in-vehicle display is a display that is provided inside an automobile 400 as a vehicle and displays various types of information. The in-vehicle displays in Fig. 15 are, for example, a CID (Center Information Display) 410A, a cluster display 410B, and side displays 410C and 410D shown in Fig. 15. The CID 410A, the cluster display 410B, and the side displays 410C and 410D are displays that use the display device 1.

[0137] CID 410A is installed in the center of the dashboard of automobile 400 and displays information from the audio, navigation system, automobile status management system, etc. Cluster display 410B displays the speedometer, etc. Side displays 410C and 410D are installed on the left and right sides of the dashboard and function as side mirrors by displaying images from cameras.

[0138] The interior of the automobile 400 in which these in-vehicle displays are installed can become a high-temperature environment due to the influence of sunlight, etc. By using the OLED display device 1, the in-vehicle display can have a long high-temperature life. Therefore, even an in-vehicle display exposed to a high-temperature environment can provide good display for a long period of time.

[0139] Although the CID 410A, the cluster display 410B, and the side displays 410C and 410D have been given as examples of in-vehicle displays, the in-vehicle display is not limited to these. The in-vehicle display may be any display provided in a vehicle. Furthermore, the display device according to the embodiment of the present specification may be used in industrial transportation equipment exposed to high-temperature environments.

[0140] Fig. 16 shows another application example of the display device according to the embodiment of the present specification. Fig. 16 schematically shows an example of an electronic device using the display device 1 according to the embodiment. Fig. 16 is a perspective view of a smartphone 450 as an electronic device. This smartphone 450 has a display device 453 according to the embodiment provided inside a housing 451, and a cover glass 452 provided on the display surface side of the display device 453. In addition, the housing 451 is provided with devices having functions required of a smartphone, such as a transmitting / receiving device, various control devices, a storage device, an audio device including a speaker and a microphone, a battery, etc.

[0141] The smartphone 450 may be used in a high-temperature environment, such as outdoors. The smartphone 450 can have a long high-temperature life by using the display device 453 according to the embodiment of the present specification. Therefore, the smartphone 450 exposed to a high-temperature environment can also provide a good display for a long period of time.

[0142] Although a smartphone has been given as an example of an electronic device, the electronic devices to which the display devices according to the embodiments of this specification can be applied are not limited to this, and may also be, for example, personal computers, PDAs (Personal Digital Assistances), tablet terminals, head-mounted displays, projectors, digital (video) cameras, etc.

[0143] FIG. 17 shows an example of a biosensor using an OLED light-emitting device according to an embodiment of the present specification. The biosensor includes an OLED element and a photodetector element according to an embodiment of the present specification. The biosensor includes red, green, and blue stacked light-emitting elements 610R, 610G, and 610B. The biosensor further includes a photodetector element 630. FIG. 17 shows one red, one green, and one blue stacked light-emitting element 610R, 610G, and 610B, respectively, as an example, and two photodetector elements 630 as an example. The stacked light-emitting elements 610R, 610G, and 610B have the same structure as the OLED display device according to the above embodiment.

[0144] The red stacked light-emitting element 610R includes red light-emitting layers 672R and 682R and hole transport layers 671R and 681R specific to the red stacked light-emitting element. The green stacked light-emitting element 610G includes green light-emitting layers 672G and 682G and hole transport layers 671G and 681G specific to the green stacked light-emitting element. The blue stacked light-emitting element 610B includes blue light-emitting layers 672B and 682B and hole transport layers 671B and 681B specific to the blue stacked light-emitting element. The photodetector element 630 includes a light-detector layer 632 and a hole transport layer 631 specific to the photodetector element.

[0145] Each of the stacked light emitting elements 610R, 610G, and 610B and the photodetector element 630 includes an anode electrode 661 and a cathode electrode 662. A hole injection layer 697 is formed between the hole transport layer 631, 671R, 671G, and 671B and the anode electrode 661.

[0146] An electron transport layer 673, an electron generating layer 693, and a hole generating layer 695 are formed between the light-emitting layers 672R, 672G, and 672B and the hole transport layers 681R, 681G, and 681B. An electron transport layer 683 and an electron injection layer 684 are formed between the light-emitting layers 682R, 682G, and 682B and the light-detecting layer 632 and the cathode electrode 662.

[0147] The encapsulating structure 621 covers all of the stacked structure light emitting elements 610R, 610G, and 610B and the photodetector element 630. The protective layer 622 is laminated on the encapsulating structure 621 so as to cover it.

[0148] The biosensor sequentially lights up stacked structure light emitting elements 610R, 610G, and 610B. Light emitted from stacked structure light emitting elements 610R, 610G, and 610B is reflected by a human body 625, and the reflected light enters a photodetector element 630, thereby detecting various biometric information. For example, in conventional technology, a red-emitting LED and a near-infrared-emitting LED are used to measure the saturated oxygen concentration in blood. On the other hand, when an OLED element is used as the light source, a green stacked structure element can be used instead of the red-emitting LED and the near-infrared-emitting LED. FIG. 17 shows an example of a sensor equipped with red, green, and blue-emitting stacked structure elements and a photodetector element, but the emission color of the stacked structure element can be appropriately selected depending on the object to be measured.

[0149] To miniaturize sensors, it is necessary to place the light-emitting elements that serve as the light source close together. OLED elements, on the other hand, have the advantage of being small, lightweight, and thin. On the other hand, there is also a need for biometric monitoring of a wide area of ​​the human body surface. OLED elements are easy to form uniform light-emitting bodies on a flat surface, and because they can also be formed on flexible substrates, they can be easily fitted to a wide area of ​​the human body surface. Furthermore, to improve sensor sensitivity, it is necessary to increase the light emission intensity from the light source. To meet these sensor needs, a configuration in which the charge generation layer is spaced apart between adjacent stacked OLED elements is expected to be applicable as a light source.

[0150] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Those skilled in the art can easily modify, add, or convert each element of the above embodiments within the scope of the present invention. It is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. [Explanation of symbols]

[0151] 1 OLED display device 25 Display area 210A, 210B Stacked structure light emitting element 253 Pixel Definition Layer 254 Aperture 256 Top surface 261 Anode electrode 270 Lower light emitting unit 271, 281 Hole transport layer 272, 282 Light-emitting layer 273, 283 electron transport layer 280 Upper light emitting unit 291A, 291B, 351A, 351B, 371A, 371B, 381A, 381B Charge generation layer 293 Electron generation layer 295 Hole generating layer 353A, 353B, 383A, 383B Electron-hole generating layer 355A, 355B, 385A, 385B Hole generating layer 400 cars 410A-410C In-Vehicle Displays 450 smartphones 453 Display

Claims

1. 1. An OLED light emitting device, comprising: an isolation layer including openings defining light emitting regions and a top surface between the openings; a bottom electrode including a first bottom electrode and a second bottom electrode exposed in the opening; a first stacked structure light emitting element disposed on the first lower electrode; a second stacked structure light emitting element adjacent to the first stacked structure light emitting element and disposed on the second lower electrode adjacent to the first lower electrode; Including, the first stacked light-emitting element includes a first light-emitting unit and a second light-emitting unit stacked above the element isolation layer, and a first charge generation layer between the first light-emitting unit and the second light-emitting unit; the first light-emitting unit and the second light-emitting unit each include a light-emitting layer; the first charge generating layer supplies charges of one polarity to the first light emitting unit and charges of the other polarity to the second light emitting unit; the second stacked light-emitting element includes a third light-emitting unit and a fourth light-emitting unit stacked above the element isolation layer, and a second charge generation layer between the third light-emitting unit and the fourth light-emitting unit; the third light-emitting unit and the fourth light-emitting unit each include a light-emitting layer; the second charge generation layer supplies charges of the one polarity to the third light-emitting unit and charges of the other polarity to the fourth light-emitting unit; the first charge generation layer and the second charge generation layer are each composed of one or more charge generation constituent layers, a first end of the first charge generation layer and a second end of the second charge generation layer overlap on a top surface of the element isolation layer; In a portion where the first end and the second end overlap, an end of a constituent layer of the first stack structure light emitting element or the second stack structure light emitting element that shields the charges of the same polarity is interposed between charge generating constituent layers that generate charges of the same polarity in the first charge generating layer and the second charge generating layer, respectively. OLED light emitting device.

2. 10. The OLED light emitting device of claim 1, the constituent layer that blocks charges of the same polarity is a constituent layer of the first charge generation layer or the second charge generation layer, and is a constituent layer that generates only charges of the same polarity and the opposite polarity; OLED light emitting device.

3. 10. The OLED light emitting device of claim 1, the constituent layer that blocks charges of the same polarity is a constituent layer of the light-emitting unit of the first stack structure light-emitting element or the second stack structure light-emitting element, and is a charge transport layer of a polarity opposite to the same polarity; OLED light emitting device.

4. 10. The OLED light emitting device of claim 1, the charge generating layer that generates charges of the same polarity generates charges of the opposite polarity to the charges of the same polarity in addition to the charges of the same polarity; Between the charge generating constituent layers that generate charges of the same polarity of the first charge generating layer and the second charge generating layer, in addition to an end of a constituent layer that blocks charges of the same polarity, an end of a constituent layer of the first stack structure light emitting element or the second stack structure light emitting element that blocks charges of the opposite polarity is interposed. OLED light emitting device.

5. 10. The OLED light emitting device of claim 1, the first charge generation layer is composed of a first charge generation constituent layer that generates only charges of a first polarity, and a second charge generation constituent layer that generates only charges of a second polarity on the first charge generation constituent layer; the second charge generation layer is composed of a third charge generation constituent layer that generates only charges of the first polarity, and a fourth charge generation constituent layer that generates only charges of the second polarity on the third charge generation constituent layer, In the overlapping portion, the first charge generation constituent layer, the second charge generation constituent layer, the third charge generation constituent layer, and the fourth charge generation constituent layer are laminated in this order from the bottom, the second charge generation constituent layer shields the charges of the first polarity between the first charge generation constituent layer and the third charge generation constituent layer; the third charge generation constituent layer shields the charges of the second polarity between the second charge generation constituent layer and the fourth charge generation constituent layer; OLED light emitting device.

6. 10. The OLED light emitting device of claim 1, the first charge generation layer is composed of a first charge generation constituent layer that generates charges of a first polarity and a second polarity, and a second charge generation constituent layer that generates only charges of the second polarity on the first charge generation constituent layer; the second charge generation layer is composed of a third charge generation constituent layer that generates charges of the first polarity and the second polarity, and a fourth charge generation constituent layer that generates only charges of the second polarity on the third charge generation constituent layer, In the overlapping portion, the first charge generation constituent layer, the second charge generation constituent layer, the third charge generation constituent layer, and the fourth charge generation constituent layer are laminated in this order from the bottom, In the overlapping portion, an end of the charge transport layer of the first polarity, which is a constituent layer of the second stacked structure light-emitting element, is interposed between the second charge generation constituent layer and the third charge generation constituent layer, an end portion of the charge transport layer of the first polarity shields the charges of the second polarity between the second charge generation layer and the third charge generation layer; OLED light emitting device.

7. 10. The OLED light emitting device of claim 1, the first charge generating layer is composed of a charge generating component layer that generates charges of a first polarity and a second polarity; the second charge generation layer is composed of a charge generation component layer that generates charges of the first polarity and the second polarity, In the overlapping portion, an end portion of the charge transport layer of the second polarity of the first stacked structure light-emitting element and an end portion of the charge transport layer of the first polarity of the second stacked structure light-emitting element are interposed between the first charge generation layer and the second charge generation layer, an end of the charge transport layer of the first polarity shields the charges of the second polarity between the first charge generation layer and the second charge generation layer; an end portion of the charge transport layer of the second polarity shields the charges of the first polarity between the first charge generation layer and the second charge generation layer; OLED light emitting device.

8. 10. The OLED light emitting device of claim 1, an end portion of the light-emitting layer of the first stacked structure light-emitting element is interposed between the first charge generation layer and the second charge generation layer in the overlapping portion; OLED light emitting device.

9. 10. The OLED light emitting device of claim 1, a first end of the first charge generation layer and a second end of the second charge generation layer having a tapered shape on a top surface of the element isolation layer; OLED light emitting device.

10. 10. An OLED light emitting device according to claim 9, the first charge generation layer includes, on a top surface of the element isolation layer, a third end portion having a tapered shape inclined along a first direction and a fourth end portion having a tapered shape inclined in a second direction perpendicular to the first direction; The taper angle of the third end is steeper than the taper angle of the fourth end. OLED light emitting device.

11. 10. The OLED light emitting device of claim 1, the first light-emitting unit and the second light-emitting unit each include a hole transport layer; an end of the hole transport layer is located on a top surface of the element isolation layer; OLED light emitting device.

12. 10. The OLED light emitting device of claim 1, the first light-emitting unit and the second light-emitting unit emit light of a first color; the third light-emitting unit and the fourth light-emitting unit emit light of a second color; the first light-emitting unit and the second light-emitting unit each include a hole transport layer; the third light-emitting unit and the fourth light-emitting unit each include a hole transport layer; the thickness of the hole transport layer of the first light-emitting unit and the second light-emitting unit is greater than the thickness of the hole transport layer of the third light-emitting unit and the fourth light-emitting unit; OLED light emitting device.

13. A display device comprising the OLED light emitting device of claim 1.

14. An electronic device comprising the OLED light emitting device according to claim 1.

15. A method for manufacturing an OLED light emitting device, comprising: forming a lower electrode; forming an element isolation layer including openings defining a light-emitting region and a top surface between the openings such that the lower electrode is exposed from each of the openings; forming a first stacked structure light emitting device and a second stacked structure light emitting device adjacent to each other on the device isolation layer; the first stacked light-emitting element includes a first light-emitting unit and a second light-emitting unit stacked above the element isolation layer, and a first charge generation layer between the first light-emitting unit and the second light-emitting unit; the first light-emitting unit and the second light-emitting unit each include a light-emitting layer; the first charge generating layer supplies charges of one polarity to the first light emitting unit and charges of the other polarity to the second light emitting unit; the second stacked light-emitting element includes a third light-emitting unit and a fourth light-emitting unit stacked above the element isolation layer, and a second charge generation layer between the third light-emitting unit and the fourth light-emitting unit; the third light-emitting unit and the fourth light-emitting unit each include a light-emitting layer; the second charge generation layer supplies charges of the one polarity to the third light-emitting unit and charges of the other polarity to the fourth light-emitting unit; the first charge generation layer and the second charge generation layer are each composed of one or more charge generation constituent layers, a first end of the first charge generation layer and a second end of the second charge generation layer overlap on a top surface of the element isolation layer; In a portion where the first end and the second end overlap, an end of a constituent layer of the first stack structure light emitting element or the second stack structure light emitting element that shields the charges of the same polarity is interposed between charge generating constituent layers that generate charges of the same polarity in the first charge generating layer and the second charge generating layer, respectively. A method for manufacturing an OLED light-emitting device.

16. 16. A method for manufacturing an OLED light emitting device according to claim 15, comprising the steps of: forming a first charge generation component layer of the first charge generation layer by vapor deposition using a metal mask aligned at a first position; After forming the first charge generating layer, the metal mask is aligned from the first position to a second position; forming a second charge generation constituent layer of the same material as the first charge generation constituent layer of the second charge generation layer by vapor deposition using the metal mask at the second position; A method for manufacturing an OLED light-emitting device.

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