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

Abstract

The present invention relates to an OLED light-emitting device, a display device, an electronic device, and a method for manufacturing an OLED light-emitting device. A first stacked structure light-emitting element includes a plurality of light-emitting units and a first charge generation layer located between the light-emitting units. A second stacked structure light-emitting element includes a plurality of light-emitting units and a second charge generation layer located between the light-emitting units. Each of the first charge generation layer and the second charge generation layer is composed of one or more charge generation component layers. The first end region of the first charge generation layer and the second end region of the second charge generation layer overlap above the top surface of the element separation layer. In the overlapping region, the end region of the component layer of the first stacked structure light-emitting element or the second stacked structure light-emitting element configured to block charges of either polarity is arranged between the charge generation component layers of the first charge generation layer and the second charge generation layer configured to generate charges of the same polarity as the charges blocked by the component layer.

Description

Technical Field

[0001] The present invention relates to an OLED light-emitting device. Background Art

[0002] Organic light-emitting diode (OLED) elements are self-luminous elements driven by current, thus requiring no backlight. OLED elements also offer the advantages of low power consumption, wide viewing angles, and high contrast; they are expected to contribute to the development of light-emitting devices such as flat-panel displays and light sources.

[0003] It is known to stack multiple light-emitting units of an OLED structure for emitting light of the same or different colors. Stacking light-emitting units for emitting light of the same color provides an OLED light-emitting device with a longer lifespan and higher brightness. Stacking red, blue, and green light-emitting units constitutes a white light-emitting element. For example, US 2015 / 0357388 A and US 2018 / 0190731 A disclose such a light-emitting element (pixel) having a stacked structure.

[0004] Stacked light-emitting elements require a charge generation layer between the light-emitting units. This layer supplies electrons to one light-emitting unit and holes to the other. However, charge leakage through the charge generation layer can occur between adjacent light-emitting units. This charge leakage can cause crosstalk between light-emitting units, reducing the light quality of OLED light-emitting devices. Summary of the Invention

[0005] One aspect of the present invention is an OLED light-emitting device, comprising: an element isolation layer having a plurality of openings defining a plurality of light-emitting regions and a top surface between the openings; a plurality of lower electrodes exposed within the openings, the plurality of lower electrodes including a first lower electrode and a second lower electrode; a first stacked light-emitting element disposed on the first lower electrode; and a second stacked light-emitting element disposed on the second lower electrode adjacent to the first lower electrode, the second stacked light-emitting element adjacent to the first stacked light-emitting element. The first stacked light-emitting element comprises a first light-emitting unit and a second light-emitting unit stacked above the element isolation layer, and a first charge generation layer positioned between the first and second light-emitting units. Each of the first and second light-emitting units comprises a light-emitting layer. The first charge generation layer is configured to supply charges of one polarity to the first light-emitting unit and charges of another polarity to the second light-emitting unit. The second stacked light-emitting element comprises a third light-emitting unit and a fourth light-emitting unit stacked above the element isolation layer, and a second charge generation layer positioned between the third and fourth light-emitting units. Each of the third and fourth light-emitting units comprises a light-emitting layer. The second charge generating layer is configured to supply charges of one polarity to the third light emitting unit and to supply charges of another polarity to the fourth light emitting unit. Each of the first charge generating layer and the second charge generating layer is composed of one or more charge generating component layers. The first end region of the first charge generating layer and the second end region of the second charge generating layer overlap above the top surface of the element separation layer. In the overlapping region of the first end region and the second end region, the end region of the component layer configured to block charges of either polarity of the first stacked structure light emitting element or the second stacked structure light emitting element is arranged between the charge generating component layers of the first charge generating layer and the second charge generating layer configured to generate charges of the same polarity as the charges to be blocked by the component layer.

[0006] One aspect of the present invention is a method for manufacturing an OLED light-emitting device. The method includes forming a plurality of lower electrodes; forming an element isolation layer having a plurality of openings defining a plurality of light-emitting regions and a top surface between the openings such that each lower electrode is exposed through the opening; and forming a first stacked structure light-emitting element and a second stacked structure light-emitting element adjacent to each other above the element isolation layer. The first stacked structure 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 positioned between the first and second light-emitting units. Each of the first and second light-emitting units includes a light-emitting layer. The first charge generation layer is configured to supply charges of one polarity to the first light-emitting unit and charges of another polarity to the second light-emitting unit. The second stacked structure 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 positioned between the third and fourth light-emitting units. Each of the third and fourth light-emitting units includes a light-emitting layer. The second charge generation layer is configured to supply charges of one polarity to the third light-emitting unit and charges of another polarity to the fourth light-emitting unit. Each of the first and second charge generation layers is composed of one or more charge generation component layers. The first end region of the first charge generation layer and the second end region of the second charge generation layer overlap above the top surface of the element separation layer. In the overlapping region of the first end region and the second end region, the end region of the component layer configured to block charges of either polarity of the first stacked structure light-emitting element or the second stacked structure light-emitting element is disposed between the charge generation component layer of the first charge generation layer and the second charge generation layer configured to generate charges of the same polarity as the charges to be blocked by the component layer.

[0007] An aspect of the present invention is to prevent or reduce degradation of light emission quality caused by crosstalk between light emitting elements.

[0008] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A diagram schematically showing a configuration example of an OLED display device;

[0010] Figure 2A It is a plan view of a portion of a stacked structure light emitting element array;

[0011] Figure 2B Schematically shows the Figure 2A The cross-sectional structure of the section line IIB-IIB;

[0012] Figure 2C yes Figure 2BAn enlarged view of the portion surrounded by the dotted line IIC;

[0013] Figure 3A is a cross-sectional view showing another configuration example of the charge generation layers of adjacent stacked structure light-emitting elements;

[0014] Figure 3B yes Figure 3A An enlarged view of the portion surrounded by the dotted line IIIB;

[0015] Figure 4 schematically illustrates a pattern of openings of a metal mask for forming a charge generation layer;

[0016] Figure 5 Another example of the pattern of the opening of the metal mask for forming the charge generation layer is schematically shown;

[0017] Figure 6 A flow chart showing a portion of manufacturing an OLED display device after forming a pixel defining layer;

[0018] Figure 7A is a cross-sectional view showing another configuration example of stacked structure light emitting elements adjacent to each other;

[0019] Figure 7B for Figure 7A An enlarged view of the portion enclosed by the middle dashed line VIIB;

[0020] Figure 8A is a cross-sectional view showing another configuration example of stacked structure light emitting elements adjacent to each other;

[0021] Figure 8B yes Figure 8A An enlarged view of the portion surrounded by the dotted line VIIIB;

[0022] Figure 9A is a cross-sectional view showing another configuration example of stacked structure light emitting elements adjacent to each other;

[0023] Figure 9B yes Figure 9A An enlarged view of the portion surrounded by the dotted line IXB;

[0024] Figure 10 is a cross-sectional view showing still another configuration example of stacked structure light emitting elements adjacent to each other;

[0025] Figure 11A It is a plan view of a portion of a stacked structure light emitting element array;

[0026] Figure 11B Schematically shows the Figure 11A A portion of the cross-sectional structure along the section line XIB-XIB;

[0027] Figure 11C Schematically shows the Figure 11A Another part of the cross-sectional structure of the section line XIC-XIC;

[0028] Figure 12 is a cross-sectional view showing another configuration example of stacked structure light emitting elements adjacent to each other;

[0029] Figure 13 It shows Figure 12 A plan view of an example of a layout of stacked structure light-emitting elements for emitting red, green, and blue light;

[0030] Figure 14 Another configuration example of a stacked structure light emitting element is shown;

[0031] Figure 15 Schematically shows an example of the configuration of a vehicle and an in-vehicle display device;

[0032] Figure 16 schematically illustrates an example configuration of a smartphone; and

[0033] Figure 17 An example of a biometric sensor to which the OLED light-emitting device according to the embodiment of this specification is applied is shown. DETAILED DESCRIPTION

[0034] Hereinafter, embodiments will be described with reference to the accompanying drawings. It should be noted that the above embodiments are merely examples of implementing the present invention and are not intended to limit the technical scope of the present invention. Common elements in the drawings are represented by the same reference numerals, and some elements in the drawings are exaggerated in size or shape to facilitate a clearer understanding of the description.

[0035] Hereinafter, an organic light emitting diode (OLED) light emitting device is disclosed. A representative example of an OLED light emitting device is an OLED display device. The OLED display device in the embodiment of the present specification includes a stacked structure light emitting element in which a plurality of light emitting units, each having an OLED structure, are stacked. In a stacked structure light emitting element, a plurality of stacked light emitting units include a light emitting layer for emitting light of the same color or different colors. In this specification, unless otherwise expressly stated, a pixel is a component for emitting light of a specific color to display an image. The specific color may be red, blue, green or white. A red pixel, a blue pixel or a green pixel may be referred to as a sub-pixel. A stacked structure light emitting element corresponds to one pixel.

[0036] A stacked structure light-emitting element includes a charge generation layer between an upper light-emitting unit and a lower light-emitting unit adjacent to each other. The charge generation layer generates charge in response to receiving a voltage. The charge generation layer supplies electrons to one light-emitting unit and holes to another light-emitting unit. When these charges leak into the charge generation layer of an adjacent stacked structure light-emitting element, this microcurrent can cause the adjacent pixel to emit slightly light (so-called crosstalk). The following embodiments describe the structure of an OLED display device that reduces or prevents this charge leakage.

[0037] The display area of ​​the OLED display device in one embodiment includes stacked structure light-emitting elements, each corresponding to a pixel. The stacked structure light-emitting element includes a plurality of stacked light-emitting units and further includes a charge generation layer between the light-emitting units. The charge generation layers of the stacked structure light-emitting elements adjacent to each other overlap on the top surface of the pixel defining layer at their ends. The pixel defining layer is an example of an element separation layer. In the overlapping area of ​​the charge generation layer, the end area of ​​the light-emitting unit or the component layer of the charge generation layer that blocks the charge of one polarity is inserted between the component layers of the charge generation layer that generate charges of this polarity. This configuration reduces charge leakage between the charge generation layers.

[0038] Display device configuration

[0039] Figure 1 An example configuration of an OLED display device 1 is schematically shown. The OLED display device 1 includes a thin-film transistor (TFT) substrate 10 on which an organic light-emitting element (OLED element) and pixel circuit are fabricated, and a thin-film encapsulation (TFE) 20 for encapsulating the OLED element. The thin-film encapsulation 20 is an example of a structural encapsulation unit. Another example of a structural encapsulation unit may include an encapsulation substrate for encapsulating the OLED element and a bonding portion (frit seal) for bonding the TFT substrate 10 to the encapsulation substrate. For example, the space between the TFT substrate 10 and the encapsulation substrate is filled with dry nitrogen.

[0040] A scan driver 31, a light-emitting driver 32, a protection circuit 33, a driver IC 34, and a demultiplexer 36 are provided around the cathode electrode region 14 outside the display region 25 of the TFT substrate 10. The driver IC 34 is connected to an external device via a flexible printed circuit (FPC) 35. The scan driver 31, the light-emitting driver 32, and the protection circuit 33 are peripheral circuits fabricated on the TFT substrate 10.

[0041] The scanning driver 31 drives the scanning lines on the TFT substrate 10. The light emission driver 32 drives the light emission control lines to control the light emission period of the pixels. For example, the driver IC 34 is mounted with an anisotropic conductive film (ACF).

[0042] The protection circuit 33 protects elements in the pixel circuit from electrostatic discharge. The driver IC 34 supplies power and timing signals (control signals) to the scan driver 31 and the light emitting driver 32 , and further supplies power and data signals to the demultiplexer 36 .

[0043] The demultiplexer 36 sequentially outputs the output of one pin of the driver IC 34 to d data lines (d is an integer greater than 1). The demultiplexer 36 changes the output data line of the data signal from the driver IC 34 d times per scanning period to drive d times as many data lines as the output pin of the driver IC 34.

[0044] Configuration of stacked structure light-emitting elements

[0045] Figure 2A It is a plan view of a portion of a stacked structure light emitting element array. Figure 2A FIG. 2 shows an example of the layout of stacked structure light emitting elements in the display area 25. Figure 2A In one configuration example, the stacked light-emitting elements emit white light. A color filter (not shown) can be provided on the front side of the stacked light-emitting elements so that each pixel emits red, blue, or green light. In another configuration example, each stacked light-emitting element emits red, blue, or green light. A group of red, blue, and green pixels displays information about a single pixel in a video frame.

[0046] Figure 2A The stacked structure light emitting elements in the embodiment have rounded rectangular light emitting regions 251 and are arranged in a matrix. As an example, one of the light emitting regions of the stacked structure light emitting elements is provided with reference numeral 251. The shape and layout of the light emitting regions of the stacked structure light emitting elements are determined as desired.

[0047] Each light emitting region 251 is surrounded by an insulating pixel defining layer 253. The pixel defining layer 253 defines each pixel (light emitting region 251). Each light emitting region 251 is disposed within an opening 254 of the pixel defining layer 253. Figure 2A As an example, one of the openings is provided with reference numeral 254 . The area between the openings 254 is the top surface of the pixel defining layer 253 .

[0048] As will be described later, each light emitting region 251 is a region of the anode electrode exposed at the bottom of the opening 254. Figure 2A As shown, the wall defining the opening of the pixel defining layer 253 is tapered, and the opening area decreases toward the bottom.

[0049] Figure 2B Schematically shows the Figure 2A The cross-sectional structure of the section line IIB-IIB. Figure 2BThe stacked structure of a given pair of stacked structure light-emitting elements 210A and 210B adjacent to each other is shown. Each of the stacked structure light-emitting elements 210A and 210B is disposed on an anode electrode exposed from an opening 254 of a pixel defining layer 253. Each of the stacked structure light-emitting elements 210A and 210B includes a plurality of stacked light-emitting units and a charge generation layer between the light-emitting units.

[0050] exist Figure 2B In the example of FIG, each of the stacked structure light emitting elements 210A and 210B includes two light emitting units stacked one on top of the other. The upper light emitting unit 280 is located above the lower light emitting unit 270. Figure 2B , one of the upper light-emitting units and one of the lower light-emitting units are provided with reference numerals by way of example. The lower light-emitting unit 270 and the upper light-emitting unit 280 may be configured to emit light of different colors, such as blue light and yellow-green light. The lower light-emitting unit 270 and the upper light-emitting unit 280 may be configured to emit the same white light.

[0051] A charge generation layer is provided 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 each have interfaces with the upper light-emitting unit 280 and the lower light-emitting unit 270. Each of the charge generation layers 291A and 291B is composed of two component layers (charge generation component layers). The details of the configuration of the charge generation layers 291A and 291B will be described later.

[0052] The stacked structure light-emitting element 210A is an example of a first stacked structure light-emitting element. The lower light-emitting unit 270, charge generation layer 291A, and upper light-emitting unit 280 of the stacked structure light-emitting element 210A are examples of a first light-emitting unit, a first charge generation layer, and a second light-emitting unit, respectively. The stacked structure light-emitting element 210B is an example of a second stacked structure light-emitting element. The lower light-emitting unit 270, charge generation layer 291B, and upper light-emitting unit 280 of the stacked structure light-emitting element 210B are examples of a third light-emitting unit, a second charge generation layer, and a fourth light-emitting unit, respectively.

[0053] like Figure 2B As shown, the OLED display device 1 includes a TFT circuit layer (TFT array) 260 and a plurality of separated lower electrodes, such as an anode electrode 261, provided on an insulating substrate. The anode electrode 261 reflects light from the light-emitting unit. The OLED display device 1 also includes an upper electrode, such as a cathode electrode 262. The cathode electrode 262 transmits light from the light-emitting unit. The cathode electrode 262 of a pixel can be part of an electrode film. The positional relationship between the anode electrode and the cathode electrode can be opposite to the positional relationship in this example. In such a configuration, the polarity of each layer is opposite.

[0054] For example, the insulating substrate is a flexible or non-flexible substrate made of resin or glass. The side close to the insulating substrate is defined as the lower side, and the side away from the insulating substrate is defined as the upper side. The stacked structure light-emitting element is arranged between the cathode electrode 262 and the anode electrode 261. Multiple anode electrodes 261 are arranged on the plane (e.g., a planarization film) of the TFT circuit layer 260, and one stacked structure light-emitting element is arranged above one anode electrode 261.

[0055] The cathode electrode 262 is a transparent (including semi-transparent) electrode that transmits all or part of the visible light from the organic light-emitting layer toward the structural packaging unit. The cathode electrode 262 of each pixel is a different part of the unseparated conductive film. A cover layer (not shown) may be provided on the cathode electrode 262.

[0056] The TFT circuit layer 260 includes a plurality of pixel circuits, each of which includes a plurality of TFTs. Each pixel circuit is formed between an insulating substrate and an anode electrode 261 to control the current supplied to the anode electrode 261. The anode electrode 261 is connected to the pixel circuit via a contact provided in a contact hole in a planarization film (not shown). Pixel circuits having a desired configuration can be employed. Examples of pixel circuits include a switching TFT for selecting a pixel, a driving TFT for an OLED element, a switching TFT for controlling the supply / stop of a driving current to the OLED element, and a storage capacitor.

[0057] The pixel defining layer 253 is provided to cover the periphery of the anode electrode 261. A portion of the anode electrode 261, including its center, is located (and exposed) within the opening 254 of the pixel defining layer 253. The region of the anode electrode 261 located within the opening 254 corresponds to the light emitting region 251. The stacked structure light emitting element is provided above the anode electrode 261 in the region within the opening 254.

[0058] The lower light emitting unit 270 includes a hole transport layer 271, a light emitting layer 272, and an electron transport layer 273. The hole transport layer 271, the light emitting layer 272, and the electron transport layer 273 are provided in this order from the bottom. Figure 2B In the configuration example of , the hole transport layer 271 is in contact with the anode electrode 261 and has an interface therewith. The light emitting layer 272 in this example emits blue light. These layers can be made of any material as appropriate.

[0059] Figure 2BThe hole transport layer 271, the light emitting layer 272, and the electron transport layer 273 in the configuration example are portions of the unseparated film that include these layers of the plurality of lower light emitting units 270. The hole transport layer 271 and / or the electron transport layer 273 are optional. The lower light emitting unit 270 may have a different stacking structure. Another functional layer, such as a hole injection layer, may be included between the anode electrode 261 and the hole transport layer 271.

[0060] The upper light emitting unit 280 includes a hole transport layer 281, a light emitting layer 282, and an electron transport layer 283. The hole transport layer 281, the light emitting layer 282, and the electron transport layer 283 are provided in this order from the bottom. Figure 2B In the configuration example of , the electron transport layer 283 is in contact with the cathode electrode 262 and has an interface therewith. The light emitting layer 282 in this example emits yellow-green light. These layers can be made of any material as appropriate.

[0061] Figure 2B The hole transport layer 281, light-emitting layer 282, and electron transport layer 283 in the configuration example are portions of the unseparated film that include these layers of the plurality of upper light-emitting units 280. The hole transport layer 281 and / or electron transport layer 283 are optional. The upper light-emitting units 280 may have different stacking structures. Another functional layer, such as an electron injection layer, may be included between the cathode electrode 262 and the electron transport layer 283.

[0062] Charge generation layers 291A and 291B are respectively positioned between the lower light emitting unit 270 and the upper light emitting unit 280. The charge generation layers 291A and 291B contact and interface 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.

[0063] As will be described later, the charge generation layer may be composed of a single component layer or a plurality of component layers. The component layers of the charge generation layer may be an electron generation layer that generates only electrons, a hole generation layer that generates only holes, or an electron and hole generation layer that generates both electrons and holes. Various materials are known for these component layers, and any of these materials may be used. For example, an organic compound or an inorganic compound such as V2O5, Re2O7, or ITO may be used. The hole transport layer or hole injection layer in the light-emitting unit for light of different colors may have different thicknesses.

[0064] The pixel defining layer 253 is a layer between the anode electrode 261 and the hole transport layer 271 of the lower light emitting unit 270. The pixel defining layer 253 includes inner walls of the openings 254 of the light emitting region 251 where the stacked structure light emitting elements are disposed and a top surface 256 between the openings 254. Figure 2B The top surface 256 in the example is flat.

[0065] like Figure 2B As shown, the charge generation layers 291A and 291B are separated. More specifically, the charge generation layers 291A and 291B respectively cover the corresponding openings 254 of the pixel defining layer 253, and their ends are located above the top surface 256 of the pixel defining layer 253. Their opposite ends are separated in the in-plane direction (the direction within the main surface of the substrate). In other words, there is a gap in the in-plane direction between the end of the charge generation layer 291A and the end of the charge generation layer 291B. The gap is filled with the material of the hole transport layer 281.

[0066] Figure 2C for Figure 2B 11 is an enlarged view of the portion surrounded by the dotted line IIC in FIG. Each of the charge generation layers 291A and 291B is composed of multiple layers. Specifically, they have a double-layer structure and include a lower electron generation layer 293 and an upper hole generation layer 295.

[0067] The charge generation layers 291A and 291B have the same structure. Their electron generation layers 293 are made of the same material and their hole generation layers 295 are made of the same material. Figure 2C In the example, the electron generation layer and the hole generation layer of the charge generation layer 291B are respectively provided with reference numerals 293 and 295. Each electron generation layer 293 supplies electrons to the lower light emitting unit 270, and each hole generation layer 295 supplies holes to the upper light emitting unit 280.

[0068] The charge generation layers 291A and 291B are disposed so as to partially cover the top surface 256 of the pixel defining layer 253 surrounding them. The charge generation layers 291A and 291B are disposed only over a portion of the top surface 256; the ends of the charge generation layers 291A and 291B are located above the top surface 256 of the pixel defining layer 253. Each electron generation layer 293 is covered by a hole generation layer 295. The ends of the charge generation layers 291A and 291B are spaced apart from each other in the in-plane direction with a gap therebetween.

[0069] The separation of charge generation layers 291A and 291B reduces leakage current between them. Since the ends of charge generation layers 291A and 291B are located above the top surface 256 of pixel defining layer 253, charge generation layers 291A and 291B can more appropriately supply charges to the upper and lower light-emitting units of the stacked structure light-emitting element.

[0070] The end regions of the charge generation layer 291A and the end regions of the charge generation layer 291B are tapered above the top surface 256 of the pixel defining layer 253. The end regions of the electron generation layer 293 and the hole generation layer 295 are tapered. Even if the films overlap due to misalignment in film formation, the tapered charge generation layers can block leakage paths due to their thin thickness.

[0071] exist Figure 2A and Figure 2B In the configuration example shown, the light-emitting layers of the lower light-emitting units of adjacent stacked structure light-emitting elements are used for light of the same color and are not separated. The light-emitting layers of the upper light-emitting units of adjacent stacked structure light-emitting elements are used for light of the same color and are not separated. The light-emitting layer of the lower light-emitting unit and the light-emitting layer of the upper light-emitting unit emit light of different colors. In another configuration example, adjacent stacked structure light-emitting elements may include light-emitting layers for light of different colors. For example, one stacked structure light-emitting element emits red light, blue light, or green light, while another stacked structure light-emitting element emits light of different colors among the three. In the case of this configuration, the light-emitting layers of different colors in adjacent lower light-emitting units are separated in the in-plane direction, and the light-emitting layers of different colors in adjacent upper light-emitting units are separated in the in-plane direction, Figure 2A and Figure 2B The charge generation layers shown are identical.

[0072] Figure 3A 2 is a cross-sectional view showing another configuration example of the charge generation layers 291A and 291B of the stacked structure light emitting elements 210A and 210B adjacent to each other. Figure 2B The configuration example is different from the Figure 3A In the configuration example, the charge generation layer 291A and the charge generation layer 291B overlap at their ends over the top surface 256 of the pixel defining layer 253. This configuration eliminates the gap separating the stacked structure light emitting elements, enabling an OLED display device with higher resolution.

[0073] Figure 3B for Figure 3A An enlarged view of the portion surrounded by dashed line IIIB in FIG. Each of charge generation layers 291A and 291B has a two-layer structure. Charge generation layer 291A comprises an electron generation layer 293A below and a hole generation layer 295A above. Charge generation layer 291B comprises an electron generation layer 293B below and a hole generation layer 295B above.

[0074] The end region of the charge generation layer 291B is positioned above the end region of the charge generation layer 291A. Specifically, the end region of the electron generation layer 293B is positioned above the end region of the hole generation layer 295A of the charge generation layer 291A. They are in contact with each other and have an interface. The stacked structure of the end region consists of the electron generation layer 293A, the hole generation layer 295A, the electron generation layer 293B, and the hole generation layer 295B, arranged in this order from the bottom.

[0075] The end regions of the charge generation layer 291A and the charge generation layer 291B are tapered above the top surface 256 of the pixel defining layer 253. The end regions of the electron generation layer 293A and the hole generation layer 295A are tapered. The end regions of the electron generation layer 293B and the hole generation layer 295B are also tapered. The tapered charge generation layers can block leakage paths.

[0076] Hole-generating layer 295A is located between electron-generating layer 293A of charge-generating layer 291A and electron-generating layer 293B of charge-generating layer 291B. Hole-generating layer 295A contacts and interfaces with electron-generating layers 293A and 293B. Electron-generating layers 293A and 293B are not in direct contact with each other and are separated by hole-generating layer 295A.

[0077] Electron generation layer 293B is located between hole generation layer 295A of charge generation layer 291A and hole generation layer 295B of charge generation layer 291B. Electron generation layer 293B is in contact with and has an interface with hole generation layers 295A and 295B. Hole generation layers 295A and 295B are not in direct contact with each other and are separated by electron generation layer 293B.

[0078] Electron-generating layers 293A and 293B supply and transport electrons but block holes and do not transport them. On the other hand, hole-generating layers 295A and 295B supply and transport holes but block electrons and do not transport them. That is, electron-generating layers 293A and 293B transport only electrons between two charges of different polarities, while hole-generating layers 295A and 295B transport only holes between two charges of different polarities.

[0079] In summary, in the overlapping region of adjacent charge generation layers, the end regions of the component layers of charge generation layer 291A or 291B that generates only charges of one polarity and blocks charges of the other polarity are interposed between the charge generation component layers of charge generation layer 291A or 291B that generates charges of the other polarity. This configuration effectively reduces charge leakage between the charge generation layers.

[0080] Film formation using a metal mask

[0081] With reference Figures 2A to 3B The charge generation layer in any of the above configurations can be formed by vapor deposition using a metal mask having a specific pattern of openings. Vapor deposition involves heating a material contained in a vapor deposition source while the source is moving. The heated material evaporates and is ejected from the nozzle of the vapor deposition source. The ejected material passes through the openings of the metal mask, which is aligned correctly between the vapor deposition source and the target substrate, and is deposited on a predetermined area of ​​the target substrate to form a film.

[0082] Figure 4 The pattern of the openings of the metal mask for forming the charge generation layer is schematically shown. Figure 4 Shown are states where a metal mask is placed in two different positions.

[0083] The rounded rectangle surrounded by the dotted line 301 schematically shows the opening pattern of the metal mask placed in the first position. Figure 4 , as an example, one of the rounded rectangles surrounded by the dashed line is provided with reference numeral 301. The rounded rectangle surrounded by the dot-dash line 303 schematically shows an opening pattern of the metal mask placed at a second position different from the first position. Figure 4 , one of the rounded rectangles surrounded by the dot-dash line is provided with reference numeral 303 as an example.

[0084] Figure 4 The metal mask in is used for vapor deposition of one component layer of the charge generation layer, such as the hole generation layer or the electron generation layer. Each component layer can be formed by vapor deposition in a different chamber by the method described below.

[0085] One embodiment of the present specification sequentially places a metal mask at different positions and forms a film twice by vapor deposition to form the constituent layers of the charge generation layer. Figure 3A The charge generation layer of the structure shown can be an electron generation layer or a hole generation layer without preparing two chambers.

[0086] exist Figure 4 In the configuration example, the openings of the metal mask are arranged in a staggered arrangement. In other words, the opening pattern includes the openings along the X axis ( Figure 4 The opening rows are arranged along the Y axis ( Figure 4 The centroids of the openings in one of two adjacent rows of openings are offset along the Y axis by half a pitch from the centroids of the openings in the other row. The distance between the centroids of adjacent openings is one pitch.

[0087] An example of forming the constituent layers of the charge generation layer performs vapor deposition of a material with a metal mask placed at a first position, then moves the metal mask to a second position and performs vapor deposition of the same material.

[0088] exist Figure 4 In the example, the position of the metal mask is determined to satisfy the following conditions. Openings 301 and openings 303 alternate along the X-axis and also along the Y-axis. Openings 301 and openings 303 adjacent along the X-axis overlap each other. However, openings 301 and openings 303 adjacent along the Y-axis are separated and do not overlap each other. Due to this positioning, the end regions of the charge generation layers of stacked structure light-emitting elements adjacent along the X-axis are arranged one above the other, and the end regions of the charge generation layers of stacked structure light-emitting elements adjacent along the Y-axis are separated.

[0089] For example, along Figure 4 The cross section of the section line AA has Figure 3A The cross-sectional structure shown. Figure 4 The cross section of the section line BB has Figure 2B The cross-sectional structure shown.

[0090] Figure 5 Another example of the pattern of the opening of the metal mask for forming the charge generation layer is schematically shown. Figure 5 Shown are states where a metal mask is placed in two different positions.

[0091] The rounded rectangle surrounded by the dashed line 305 schematically shows the opening pattern of the metal mask placed at the first position. Figure 5 , as an example, one of the rounded rectangles surrounded by dashed lines is provided with reference numeral 305. The rounded rectangle surrounded by dot-dash lines 307 schematically shows an opening pattern of the metal mask placed at a second position different from the first position. Figure 5 , one of the rounded rectangles surrounded by the dot-dash line is provided with reference numeral 307 as an example.

[0092] Figure 5 The openings of the metal mask shown are arranged in a staggered arrangement, similar to Figure 4 The configuration example in the . Figure 5 In the example of FIG. 5 , the position of the metal mask is determined to satisfy the following conditions: The openings 305 and the openings 307 alternate along the X-axis and also alternate along the Y-axis.

[0093] Among pairs of openings 305 and openings 307 adjacent along the X-axis, the openings of some pairs overlap each other, while the openings of other pairs are separated from each other and do not overlap each other. Among pairs of openings 305 and openings 307 adjacent along the Y-axis, the openings of some pairs overlap each other, while the openings of other pairs are separated from each other and do not overlap each other.

[0094] As a result of this positioning, there are produced a stacked structure light emitting element pair whose charge generation layers are arranged one above the other at their ends and a stacked structure light emitting element pair whose charge generation layers are separated from each other. Figure 5 In the configuration example, each opening 305 overlaps with one of the openings 307 adjacent to it along the X-axis (the opening 307 on the left) and is spaced apart from the other opening 307 (the opening 307 on the right). Furthermore, each opening 305 overlaps with one of the openings 307 adjacent to it along the Y-axis (the opening 307 on the upper side) and is spaced apart from the other opening 307 (the opening on the lower side).

[0095] For example, along Figure 5 The cross section of the section lines CC and EE has Figure 3A The cross-sectional structure shown. Figure 5 The cross section of the section lines DD and FF has Figure 2B The cross-sectional structure shown.

[0096] As reference Figure 4 and Figure 5 As described above, the charge generation layers of adjacent stacked structure light-emitting elements can have different structures depending on the direction. In another configuration example, the charge generation layer of each stacked structure light-emitting element can be away from or overlap with the charge generation layers of all adjacent stacked structure light-emitting elements along the X-axis and the Y-axis.

[0097] Method for manufacturing OLED display device

[0098] An example method for manufacturing an OLED display device 1 is described below. In the following description, components manufactured in the same step (or together) are referred to as components on the same layer. The manufacturing of the OLED display device 1 begins by fabricating a TFT circuit layer 260 on an insulating substrate. The TFT circuit layer 260 can be manufactured using well-known techniques, and therefore will not be described in detail here.

[0099] Next, anode electrodes are formed above the TFT circuit layer 260. For example, anode electrodes 261 are formed on a planarization film having contact holes therethrough. The layer structure and material of anode electrodes 261 can be determined as desired. For example, anode electrodes 261 can be formed by vapor deposition or sputtering of a metal material. Each anode electrode 261 is connected to a pixel circuit in the TFT circuit layer 260 via a contact.

[0100] Next, a photosensitive organic resin is deposited by spin coating and patterning to form a pixel defining layer 253. An opening 254 is generated in the pixel defining layer 253 by patterning, so that the anode electrode 261 of a single pixel is exposed at the bottom of the opening 254. The light emitting area is separated by the pixel defining layer 253.

[0101] Reference Figure 6 The flowchart of FIG. 1 describes some manufacturing steps after producing the pixel defining layer 253. A hole transport layer 271, a light emitting layer 272, and an electron transport layer 273 are sequentially formed on the entire display area having the pixel defining layer 253 (S101). These layers can be formed by vapor deposition.

[0102] Next, the electron generation layer 293A is formed by depositing a material for the electron generation layer on the substrate by vapor deposition using a metal mask having a pattern of the electron generation layers 293A and 293B (S102). The electron generation layer 293A is formed by referring to Figure 4 or Figure 5 The method described is formed.

[0103] Next, a material for the hole generation layer is deposited on the substrate by vapor deposition using a metal mask having a pattern of the hole generation layers 295A and 295B to form the hole generation layer 295A (S103). The hole generation layer 295A is formed by referring to Figure 4 or Figure 5 The method described is formed.

[0104] Next, the electron generation layer 293B is formed by depositing a material for the electron generation layer on the substrate by vapor deposition using a metal mask having a pattern of the electron generation layers 293A and 293B (S104). The electron generation layer 293B is formed by referring to Figure 4 or Figure 5 The method described is formed.

[0105] Next, a material for the hole generation layer is deposited on the substrate by vapor deposition using a metal mask having a pattern of the hole generation layers 295A and 295B to form the hole generation layer 295B (S105). The hole generation layer 295B is formed by referring to Figure 4 or Figure 5 The method described is formed.

[0106] Next, a hole transport layer 281, a light emitting layer 282, and an electron transport layer 283 are sequentially formed over the entire display area (S106). These layers can be formed by vapor deposition. Next, a metal material for the cathode electrode 262 is deposited (S107). The cathode electrode 262 is disposed over the entire display area. The layer structure and material of the cathode electrode 262 are determined as desired. For example, the cathode electrode 262 can be formed by vapor deposition or sputtering of a metal material. After the cathode electrode 262 is made, a color filter layer and a structural encapsulation unit are formed.

[0107] The above method is just one example; OLED display devices can be manufactured using various methods. For example, if an OLED display device is configured to display images using stacked light-emitting elements that emit red, blue, and green light, the light-emitting layers for these colors can be formed by vapor deposition using metal masks for the light-emitting layers of each color. An OLED display device with this configuration does not include color filters.

[0108] Other configuration examples of stacked structure light-emitting elements

[0109] Hereinafter, other configuration examples of stacked structure light emitting elements will be described. Figure 3A Differences from the configuration examples described. Figure 7A 2 is a cross-sectional view illustrating another configuration example of stacked structure light emitting elements 210A and 210B adjacent to each other. Figure 7B for Figure 7A An enlarged view of the portion enclosed by the dotted line VIIB.

[0110] Figure 7A The configuration example shown in FIG includes charge generation layers 351A and 351B, instead of Figure 3A The charge generation layers 291A and 291B in FIG. The charge generation layer 351A and the charge generation layer 351B overlap at their ends over the top surface 256 of the pixel defining layer 253. This configuration enables the OLED display device to have a higher resolution.

[0111] Each of the charge generation layers 351A and 351B has a double-layer structure and is composed of two component layers. Specifically, the charge generation layer 351A is composed of an electron and hole generation layer 353A below and a hole generation layer 355A above. Similarly, the charge generation layer 351B is composed of an electron and hole generation layer 353B below and a hole generation layer 355B above. The electron and hole generation layers 353A and 353B can be made of an alkali metal compound or an alkaline earth metal compound; they can supply and transport charges (carriers) of electrons and holes. The hole generation layers 355A and 355B only supply and transport holes.

[0112] like Figure 7BAs shown, the end region of the charge generation layer 351B is located above the end region of the charge generation layer 351A. The end region of the charge generation layer 351A is located above the end region of the electron transport layer 273A of the lower light-emitting unit of the stacked structure light-emitting element 210A. The end region of the charge generation layer 351A and the end region of the charge generation layer 351B are tapered above the top surface 256 of the pixel defining layer 253. The end regions of the electron and hole generation layer 353A and the hole generation layer 355A are tapered. The end regions of the electron and hole generation layer 353B and the hole generation layer 355B are also tapered. The tapered charge generation layer can block leakage paths.

[0113] The end region of the electron transport layer 273B of the lower light-emitting unit of the stacked structure light-emitting element 210B is interposed between the end region of the charge generation layer 351A and the end region of the charge generation layer 351B. The end region of the charge generation layer 351B is positioned above the end region of the charge generation layer 351A, with the end region of the electron transport layer 273B interposed therebetween. The end region of the electron transport layer 273B contacts the end regions of the charge generation layers 351A and 351B and forms an interface therewith.

[0114] The stacked structure of the end region of the charge generation layer includes the electron and hole generation layer 353A, the hole generation layer 355A, the electron transport layer 273B, the electron and hole generation layer 353B, and the hole generation layer 355B in this order from the bottom.

[0115] The electron transport layer 273B is located between the hole generating layer 355A of the charge generating layer 351A and the electron and hole generating layer 353B of the charge generating layer 351B. The electron transport layer 273B is in contact with the hole generating layer 355A and the electron and hole generating layer 353B and has an interface therewith. The hole generating layer 355A is not in direct contact with the electron and hole generating layer 353B, and these layers are separated by the electron transport layer 273B.

[0116] The electron transport layer 273B transports electrons and blocks holes without transporting holes. Therefore, the electron transport layer 273B blocks the flow of holes between the electron and hole generation layer 353B and the hole generation layer 355A.

[0117] The hole generating layer 355A of the charge generating layer 351A is located between the electron transport layer 273B and the electron and hole generating layer 353A of the charge generating layer 351A. The hole generating layer 355A is in contact with the electron and hole generating layer 353A and the electron transport layer 273B and has an interface with them. The electron transport layer 273B is not in direct contact with the electron and hole generating layer 353A, and these layers are separated by the hole generating layer 355A. Therefore, the electron and hole generating layer 353A of the charge generating layer 351A is not in direct contact with the electron and hole generating layer 353B of the charge generating layer 351B, and these layers are separated by the electron transport layer 273B and the hole generating layer 355A.

[0118] The electron transport layer 273B transports electrons and blocks holes without transporting holes. The hole generation layer 355A blocks the flow of electrons. These layers block the flow of electrons and holes between the electron and hole generation layer 353B and the electron and hole generation layer 353A.

[0119] Electron transport layer 273B is located between hole generating layer 355A of charge generating layer 351A and hole generating layer 355B of charge generating layer 351B. Electron transport layer 273B contacts hole generating layer 355A and electron and hole generating layer 353B and has an interface therewith. Hole generating layer 355A does not directly contact electron and hole generating layer 353B, and these layers are separated by electron transport layer 273B. Electron transport layer 273B blocks the flow of holes between hole generating layers 355A and 355B.

[0120] refer to Figure 7A and Figure 7B As described, the end region of the electron transport layer 273B that blocks holes is interposed between the charge generation component layers 355A and 353B that generate holes of the charge generation layers 351A and 351B. The electron transport layer 273B is a component layer of the light emitting unit of the stacked structure light emitting element 210B. The electron and hole generating layers 353A and 353B generate holes and electrons, as shown in FIG. Figure 7A and Figure 7B Except for the end region of the electron transport layer 273B that blocks holes, the end region of the hole generation layer 355A that blocks electrons is interposed between the electron and hole generation layer 353A and the electron and hole generation layer 353B.

[0121] As mentioned above, Figure 7A and Figure 7B The illustrated configuration example effectively reduces charge leakage at portions where end regions of the charge generation layer adjacent to each other are stacked.

[0122] Figure 7A and Figure 7BThe stacked structure shown can be formed by separately depositing the electron transport layer and charge generation layer of the lower light-emitting unit. For example, using an alignment function, a metal mask is placed at two different positions to form electron transport layers 273A and 273B, as described in the formation of the charge generation layer. This stacked structure is produced by forming the layers in the order of electron transport layer 273A, charge generation layer 351A, electron transport layer 273B, and charge generation layer 351B. By using the same metal mask, efficient manufacturing of OLED display devices is achieved.

[0123] Figure 8A 2 is a cross-sectional view illustrating still another configuration example of stacked-structure light-emitting elements 210A and 210B adjacent to each other. Figure 8B yes Figure 8A An enlarged view of the portion surrounded by the dotted line VIIIB.

[0124] Figure 8A The illustrated configuration example includes charge generation layers 371A and 371B instead of Figure 3A The charge generation layers 291A and 291B in FIG. The charge generation layer 371A and the charge generation layer 371B overlap at their ends above the top surface 256 of the pixel defining layer 253. This configuration enables the OLED display device to have a higher resolution.

[0125] Each of the charge generation layers 371A and 371B has a single-layer structure and is composed of a single component layer. Specifically, the charge generation layers 371A and 371B supply and transport charges of both polarities, electrons and holes. For example, the charge generation layers 371A and 371B can be made of ITO or V2O5.

[0126] like Figure 8B As shown, the end region of charge generation layer 371B is located above the end region of charge generation layer 371A. The end region of charge generation layer 371A is located above the end region of electron transport layer 273A of the lower light-emitting unit of stacked structure light-emitting element 210A. The end regions of charge generation layers 371A and 371B have a tapered shape above the top surface 256 of pixel defining layer 253. The tapered charge generation layer can block leakage paths.

[0127] The end region of hole transport layer 281A of the upper light-emitting unit of stacked structure light-emitting element 210A and the end region of electron transport layer 273B of the lower light-emitting unit of stacked structure light-emitting element 210B are located between the end region of charge generation layer 371A and the end region of charge generation layer 371B. The end region of charge generation layer 371B is located above the end region of charge generation layer 371A, sandwiching the end region of hole transport layer 281A and the end region of electron transport layer 273B.

[0128] The end region of the hole transport layer 281A contacts and interfaces with the end regions of the charge generation layer 371A and the electron transport layer 273B. The end region of the electron transport layer 273B contacts and interfaces with the end regions of the hole transport layer 281A and the charge generation layer 371B.

[0129] The stacked structure of the end region of the charge generation layer includes the charge generation layer 371A, the hole transport layer 281A, the electron transport layer 273B, and the charge generation layer 371B, which are arranged in this order from the bottom.

[0130] The hole transport layer 281A and the electron transport layer 273B are located between the charge generation layers 371A and 371B. The charge generation layer 371A is not in direct contact with the electron transport layer 273B, and these layers are separated by the hole transport layer 281A. The hole transport layer 281A is not in direct contact with the charge generation layer 371B, and these layers are separated by the electron transport layer 273B. In other words, the charge generation layers 371A and 371B are not in direct contact with each other, and these layers are separated by the hole transport layer 281A and the electron transport layer 273B disposed above each other.

[0131] The hole transport layer 281A transports holes and blocks electrons without transporting them. The electron transport layer 273B transports electrons and blocks holes without transporting them. Thus, the hole transport layer 281A and the electron transport layer 273B, disposed one above the other, block the flow of holes and electrons between the charge generation layers 371A and 371B.

[0132] As reference Figure 8A and Figure 8B As described, the end region of the electron transport layer 273B that blocks holes is located between the charge generation layers 371A and 371B that generate holes, and the end region of the hole transport layer 281A that blocks electrons is located between the charge generation layers 371A and 371B that generate electrons. The charge generation layers 371A and 371B generate electrons and holes, as shown in FIG. Figure 8A and Figure 8B Except for the end region of the electron transport layer 273B that blocks holes, the end region of the hole transport layer 281A that blocks electrons is located between the charge generation layers 371A and 371B.

[0133] As mentioned above, Figure 8A and Figure 8B The illustrated configuration example effectively reduces charge leakage at portions where end portions of charge generation layers adjacent to each other are stacked. Figure 8A and Figure 8BThe stacked structure shown can be produced by depositing the electron transport layer of the lower light-emitting unit separately onto the hole transport layer of the upper light-emitting unit. For example, the metal mask is placed at two different locations using the alignment function to form the hole transport layers 281A and 281B and the electron transport layers 273A and 273B, as described in the formation of the charge generation layer. The stacked structure is produced by forming the layers in the order of 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. By using the same metal mask, efficient manufacturing of the OLED display device is achieved.

[0134] Figure 9A 2 is a cross-sectional view illustrating still another configuration example of stacked-structure light-emitting elements 210A and 210B adjacent to each other. Figure 9B yes Figure 9A An enlarged view of the portion enclosed by the dotted line IXB. Figure 9A The illustrated configuration example includes charge generation layers 381A and 381B instead of Figure 3A The charge generation layers 291A and 291B in FIG. The charge generation layer 381A and the charge generation layer 381B overlap at their ends above the top surface 256 of the pixel defining layer 253. This configuration enables the OLED display device to have a higher resolution.

[0135] The charge generation layer 381A is composed of an electron and hole generation layer 383A below and a hole generation layer 385A above. Similarly, the charge generation layer 381B is composed of an electron and hole generation layer 383B below and a hole generation layer 385B above. The charge generation layers 381A and 381B may have different structures, for example, Figure 3B 、 Figure 7B and Figure 8B The stacking structure shown.

[0136] like Figure 9B As shown, the end region of charge generation layer 381B is located above the end region of charge generation layer 381A. The end regions of hole transport layer 281A and light-emitting layer 282A of the upper light-emitting unit of stacked structure light-emitting element 210A are located between the end regions of charge generation layer 381A and the end regions of charge generation layer 381B. The end region of charge generation layer 381B is located above the end region of charge generation layer 381A, sandwiching the end regions of hole transport layer 281A and light-emitting layer 282A.

[0137] The end regions of the charge generation layers 381A and 381B have a tapered shape above the top surface 256 of the pixel defining layer 253. The end regions of the electron and hole generation layer 383A and the hole generation layer 385A have a tapered shape. The end regions of the electron and hole generation layer 383B and the hole generation layer 385B also have a tapered shape. The tapered charge generation layers can block leakage paths.

[0138] The end region of the hole transport layer 281A is in contact with and has an interface with the end region of the hole generating layer 385A of the charge generating layer 381A and the end region of the light emitting layer 282A. The end region of the light emitting layer 282A is in contact with and has an interface with the end region of the hole transport layer 281A and the end region of the electron and hole generating layer 383B of the charge generating layer 381B.

[0139] The stacked structure of the end region of the charge generation layer includes an electron and hole generation layer 383A, a hole generation layer 385A, a hole transport layer 281A, a light emitting layer 282A, an electron and hole generation layer 383B, and a hole generation layer 385B arranged in the following order from the bottom.

[0140] The light-emitting layer 282A is located between the hole transport layer 281A and the electron and hole generating layer 383B of the charge generating layer 381B. The hole transport layer 281A is not in direct contact with the electron and hole generating layer 383B, and these layers are separated by the light-emitting layer 282A. Focusing on the relationship between the charge generating layers 381A and 381B, the charge generating layers 381A and 381B are not in direct contact with each other, and these layers are separated by the light-emitting layer 282A interposed therebetween.

[0141] The light-emitting layer has a low mobility compared to other layers. For example, the hole mobility of the hole transport layer is about 10 - 4 cm 2 / Vs, and the hole mobility of the light-emitting layer is about 10 -11 cm 2 For this reason, the light emitting layer 282A effectively reduces charge leakage in the stacked structure of the end regions of the charge generation layers adjacent to each other.

[0142] As mentioned above, in Figure 9A and Figure 9B In the illustrated configuration example, the light emitting layer 282A is interposed between the charge generation layers 381A and 381B in the overlapping region of the charge generation layers adjacent to each other. This configuration effectively reduces charge leakage between the charge generation layers 381A and 381B. Figure 9BIn a configuration example, the end region of the light-emitting layer 282A is not in direct contact with the end region of the charge-generating layer 381A, and these layers are separated by the end region of the hole-transporting layer 281A. In another configuration example, a portion of the end region of the light-emitting layer 282A may be in contact with the end region of the charge-generating layer 381A.

[0143] like Figure 9B As shown, the end region of the hole transport layer 281B and the end region of the light emitting layer 282B of the upper light emitting unit of the stacked structure light emitting element 210B are placed above the end region of the charge generation layer 381B. Figure 9A and Figure 9B The stacked structure in the embodiment can be formed by depositing the charge generation layer separately onto the light-emitting layer of the upper light-emitting unit. For example, the metal mask is placed at two different locations using the alignment function to form the hole transport layers 281A and 281B and the light-emitting layers 282A and 282B, as described in the formation of the charge generation layer. The stacked structure is produced by forming the layers in the order of charge generation layer 381A, hole transport layer 281A, light-emitting layer 282A, charge generation layer 381B, hole transport layer 281B, and light-emitting layer 282B. Efficient manufacturing of OLED display devices is achieved by using the same metal mask.

[0144] Another example of a stacked structure light emitting element is described. Figure 10 2 is a cross-sectional view showing another configuration example of stacked structure light emitting elements 210A and 210B adjacent to each other. Figure 2B The configuration example in . Figure 10 In the configuration example, an end portion of the hole transport layer of the lower light emitting unit and an end portion of the hole transport layer of the upper light emitting unit are located above the top surface of the pixel defining layer.

[0145] Figure 10 The portion surrounded by the middle dashed line 510 corresponds to a portion including the end regions of the charge generation layer 291A and the hole transport layer 511A of the stacked structure light-emitting element 210A and the end regions of the charge generation layer 291B and the hole transport layer 511B of the stacked structure light-emitting element 210B.

[0146] The charge generation layers 291A and 291B are provided only over a portion of the top surface of the pixel defining layer 253, and the ends of the charge generation layers 291A and 291B are located above the top surface of the pixel defining layer 253. The ends of the charge generation layers 291A and 291B are separated from each other in the in-plane direction with a gap therebetween.

[0147] The hole transport layers 511A and 511B are disposed only above a portion of the top surface of the pixel defining layer 253; the ends of the hole transport layers 511A and 511B are located above the top surface of the pixel defining layer 253. The ends of the hole transport layers 511A and 511B are spaced apart from each other in the in-plane direction and have a gap therebetween. The end region of the hole transport layer 511A has a tapered shape and covers the end region of the charge generation layer 291A. The end region of the hole transport layer 511B has a tapered shape and covers the end region of the charge generation layer 291B. The hole transport layer 511A, the light emitting layer 282, and the hole transport layer 511B are interposed in the in-plane direction between the ends of the charge generation layer 291A and the charge generation layer 291B.

[0148] Figure 10 The portion surrounded by the middle dashed line 520 corresponds to a portion including the end region of the hole transport layer 521A of the stacked structure light-emitting element 210A and the end region of the hole transport layer 521B of the stacked structure light-emitting element 210B. The hole transport layers 521A and 521B are disposed only above a portion of the top surface of the pixel defining layer 253; the ends of the hole transport layers 521A and 521B are located above the top surface of the pixel defining layer 253. The ends of the hole transport layers 521A and 521B are separated from each other in the in-plane direction and a gap exists between them. The end regions of the hole transport layers 521A and 521B have a tapered shape. The light-emitting layer 272 is located in the in-plane direction between the end of the hole transport layer 521A and the end of the hole transport layer 521B.

[0149] Another example of the structure of the stacked structure light emitting element is described below. Figures 2A to 2C Differences from the configuration examples described. Figure 11A It is a plan view of a portion of a stacked structure light emitting element array. Figure 11B Shown along Figure 11A A portion of the cross-sectional structure along the section line XIB-XIB. Figure 11C Shown along Figure 11A Another part of the cross-sectional structure of the section line XIC-XIC in FIG. Section line XIB-XIB is a section line extending along the X-axis, and section line XIC-XIC is a section line extending along the Y-axis.

[0150] Figure 11B The boundary region between two adjacent stacked structure light emitting elements along the X axis is shown. Figure 11C The boundary between two adjacent stacked structure light emitting elements along the Y axis is shown. Figure 11B and Figure 11CAs shown, the charge generation layers 291A and 291B are provided to partially cover the top surface 256 of the pixel defining layer 253 surrounding them. The charge generation layers 291A and 291B are provided only over a portion of the top surface 256 and their ends are located above the top surface 256 of the pixel defining 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 away from each other in the in-plane direction and a gap exists between them.

[0151] The end region of the charge generation layer 291A and the end region of the charge generation layer 291B have a tapered shape above the top surface 256 of the pixel defining layer 253. The tapered charge generation layers can block leakage paths because of their thin thickness even when the films overlap due to misalignment in film formation. Figure 11B The taper ratio along the X axis shown in Figure 11C The taper of the Y axis is shown to be steeper. More specifically, Figure 11B The angle of the inclined surface at the end (third end) of the hole generating layer 295 and the electron generating layer 293 (relative to the plane of the pixel defining layer 253) is greater than Figure 11C The angle of the inclined surface at the end portion (fourth end portion) of the hole generation layer 295 and the electron generation layer 293 in FIG.

[0152] The above structures with different taper angles can be formed by vapor deposition of the hole generation layer 295 and the electron generation layer 293 using a mask. A vapor deposition source sprays vaporized material from the opening of a nozzle toward the outside. One example of a vapor deposition source has nozzles arranged along the X-axis and moves along the Y-axis while spraying the vaporized material.

[0153] Another example of a stacked structure light emitting element is described. Figure 12 It is a cross-sectional view showing another configuration example of stacked structure light emitting elements adjacent to each other. Figure 2B The difference between the configuration examples in FIG. 2 and FIG. 3 is that the stacked structure light emitting element 210R emits red light, and the stacked structure light emitting element 210G emits green light. In addition to the stacked structure light emitting elements for emitting these colors of light, the display area includes a stacked structure light emitting element for emitting blue light.

[0154] The lower light-emitting unit 270 and the upper light-emitting unit 280 of the stacked structure light-emitting element 210R both emit red light. This means that the light-emitting layers 272R and 282R of the two light-emitting units of the stacked structure light-emitting element 210R emit red light. The lower light-emitting unit 270 and the upper light-emitting unit 280 of the stacked structure light-emitting element 210G both emit green light. This means that the light-emitting layers 272G and 282G of the two light-emitting units of the stacked structure light-emitting element 210G emit green light. The light-emitting layers of the two light-emitting units of the stacked structure blue light-emitting element both emit blue light.

[0155] Figure 13 It shows Figure 12 FIG. 1 is a plan view of an example of a layout of stacked-structure light-emitting elements for emitting red, green, and blue light. Figure 13 A portion of a stacked structure light emitting element array is shown and an example of a stripe layout is shown, where stacked structure light emitting elements for red, green and blue light are arranged cyclically along the X axis and stacked structure light emitting elements for the same color light are arranged along the Y axis.

[0156] refer to Figure 11B and Figure 11C The description provided is applicable to this configuration example. As described above, the taper along the X axis is steeper than the taper along the Y axis. This configuration effectively reduces charge leakage between stacked structure light emitting elements for emitting light of different colors.

[0157] Figure 14 FIG. 1 schematically shows another example of the structure of a stacked-structure light-emitting element. Figure 14 The stacked structure light emitting elements 210R, 210G and 210B for emitting red light, green light and blue light are shown. Figure 14 The stacked structure light emitting element 210R that emits red light includes red light emitting layers 272R and 282R and hole transport layers 271R and 281R that are inherent to the stacked structure light emitting element that emits red light.

[0158] The stacked structure light-emitting element 210G that emits green light includes green light-emitting layers 272G and 282G and hole transport layers 271G and 281G that are inherent to the stacked structure light-emitting element. The stacked structure light-emitting element 210B that emits blue light includes blue light-emitting layers 272B and 282B and hole transport layers 271B and 281B that are inherent to the stacked structure light-emitting element. A hole injection layer 297 is provided between the anode electrode (ITO) 261 and the hole transport layers 271R, 271G, and 271B.

[0159] The stacked structure light-emitting elements 210R, 210G, and 210B for different colors of light include hole transport layers with different thicknesses. Specifically, the total thickness of the hole transport layers 271R and 281R of the stacked structure light-emitting element 210R emitting red light is the largest, and the total thickness of the hole transport layers 271B and 281B of the stacked structure light-emitting element 210B emitting blue light is the smallest.

[0160] exist Figure 14In the example of FIG. 1 , the hole transport layer 271R is thicker than the hole transport layers 271G and 271B, and the hole transport layer 271G is thicker than the hole transport layer 271B. The hole transport layer 281R is thicker than the hole transport layers 281G and 281B, and the hole transport layer 281G is thicker than the hole transport layer 281B. Each light emitting unit may include Figure 14 The hole injection layer is not shown.

[0161] exist Figure 14 In the example, the lower light-emitting units of the stacked structure light-emitting elements for different colors of light have different total thicknesses, and the upper light-emitting units of the stacked structure light-emitting elements for different colors of light have different total thicknesses. Specifically, the light-emitting units of the stacked structure light-emitting elements emitting red light are the thickest, and the light-emitting units of the stacked structure light-emitting elements emitting blue light are the thinnest.

[0162] As described above, stacked-structure light-emitting elements achieve higher luminous efficiency by including hole transport layers / hole injection layers (HTLs or HILs) with varying thicknesses depending on the color of the light-emitting layer of the stacked-structure light-emitting element. Due to the varying thicknesses, the HTLs / HILs are formed separately for each light-emitting layer. The charge generation layer separated between the stacked-structure light-emitting elements reduces charge leakage between the stacked-structure light-emitting elements.

[0163] The display area described in the above embodiment has a top-emitting pixel structure. The top-emitting pixel structure includes a cathode electrode located on the light-emitting side (the upper side of the drawing). The cathode electrode has a shape that completely covers the entire display area. The features of the present invention can be applied to an OLED display device with a bottom-emitting pixel structure. The bottom-emitting pixel structure includes a transparent anode electrode and a reflective cathode electrode, and emits light to the outside through a TFT substrate.

[0164] Application Examples

[0165] Hereinafter, application examples of the OLED light-emitting device according to the embodiment of this specification are described. Figure 15 An example of a vehicle-mounted display device employing the display device according to the embodiment is schematically shown. Figure 15 A configuration example of a car 400 equipped with the in-vehicle display apparatus in the present embodiment and in-vehicle display devices 410A to 410D is shown.

[0166] The in-vehicle display device is installed inside a car 400 as an example of a vehicle to display various information. Figure 15 The vehicle-mounted display devices in FIG. 4 are a central information display (CID) 410A, a cluster display 410B, and side displays 410C and 410D. The CID 410A, the cluster display 410B, and the side displays 410C and 410D are display devices employing the display device 1 .

[0167] For example, CID 410A is mounted in the center of the dashboard of car 400 and displays information related to the audio system, navigation system, and vehicle condition management system. Cluster display 410B displays the odometer, for example. Side displays 410C and 410D are mounted on the left and right sides of the dashboard to function as side mirrors by displaying images from cameras.

[0168] The interior of a vehicle 400 equipped with these in-vehicle display devices is subject to high temperatures due to sunlight. By employing the OLED display device 1, the in-vehicle display device can have a longer high-temperature lifespan. Therefore, the in-vehicle display device can provide high-quality display for a long time even in a high-temperature environment.

[0169] Although CID 410A, cluster display 410B, and side displays 410C and 410D are provided as examples of vehicle-mounted display devices, vehicle-mounted display devices are not limited thereto. The vehicle-mounted display device may be any type of display device designed to be installed in a vehicle. Display devices according to embodiments of the present specification may be used in industrial conveying machinery exposed to high temperature environments.

[0170] Figure 16 This is another application example of the display device according to the embodiment of this specification. Figure 16 An example of an electronic device including the display device 1 according to the embodiment is schematically shown. Figure 16 This is a perspective view of a smartphone 450, an electronic device. This smartphone 450 includes a display device 453 according to an embodiment, housed in a housing 451. Display device 453 is covered on its side with cover glass 452 for displaying images. In addition to these components, housing 451 also includes devices for providing the necessary smartphone functions, such as a transmitter, receiver, various controllers, storage, audio equipment including a speaker and microphone, and a battery.

[0171] Smartphone 450 may sometimes be used outdoors in high-temperature environments. By employing display device 453 according to an embodiment of this specification, smartphone 450 can have a long high-temperature lifespan. Therefore, smartphone 450 can provide a high-quality display for a long time even when exposed to high-temperature environments.

[0172] Although a smartphone is provided as an example of an electronic device, the electronic devices to which the display device according to the embodiment can be applied are not limited thereto. For example, a personal computer, a personal digital assistant (PDA), a tablet terminal, a head-mounted display, a projector, and a digital (video) camera may include the display device according to the embodiment.

[0173] Figure 17An example of a biometric sensor using an OLED light-emitting device according to an embodiment of this specification is shown. The biometric sensor includes an OLED element according to an embodiment of this specification and a photodetector. The biometric sensor includes stacked light-emitting elements 610R, 610G, and 610B for red, green, and blue light. The biometric sensor also includes a photodetector 630. Figure 17 Each of stacked structure light emitting elements 610R, 610G and 610B for red, green and blue light and two photodetectors 630 are provided by way of example. The stacked structure light emitting elements 610R, 610G and 610B have the same structure as the corresponding OLED display device in the aforementioned embodiment.

[0174] The stacked structure light-emitting element 610R that emits red light includes red light-emitting layers 672R and 682R and hole transport layers 671R and 681R that are inherent to the stacked structure light-emitting element. The stacked structure light-emitting element 610G that emits green light includes green light-emitting layers 672G and 682G and hole transport layers 671G and 681G that are inherent to the stacked structure light-emitting element. The stacked structure light-emitting element 610B that emits blue light includes blue light-emitting layers 672B and 682B and hole transport layers 671B and 681B that are inherent to the stacked structure light-emitting element. The photodetector 630 includes a photodetection layer 632 and a hole transport layer 631 that is inherent to the photodetector.

[0175] Each of the stacked structure light emitting elements 610R, 610G, and 610B and the photodetector 630 includes an anode electrode 661 and a cathode electrode 662. A hole injection layer 697 is provided between the anode electrode 661 and the hole transport layers 631, 671R, 671G, and 671B.

[0176] An electron transport layer 673, an electron generation layer 693, and a hole generation layer 695 are provided between the light-emitting layers 672R, 672G, and 672B and the hole transport layers 681R, 681G, and 681B. Another electron transport layer 683 and an electron injection layer 684 are provided between the cathode electrode 662 and the light-emitting layers 682R, 682G, and 682B and the photodetection layer 632.

[0177] The structure encapsulation unit 621 covers all the stacked structure light emitting elements 610R, 610G, and 610B and the photodetector 630. A protective layer 622 is provided on the structure encapsulation unit 621 to cover the structure encapsulation unit 621.

[0178] The biometric sensor sequentially lights up the stacked structure light emitting elements 610R, 610G, and 610B. The light emitted from the stacked structure light emitting elements 610R, 610G, and 610B is reflected by the human body 625 and enters the photodetector 630, so that the biometric sensor detects various biological information. For example, the previous biometric sensor for measuring blood oxygen levels includes a red LED and a near-infrared LED. In contrast, a biometric sensor using an OLED element as a light source may include a stacked structure light emitting element that emits red light and a stacked structure light emitting element that emits green light instead of the near-infrared LED. Although Figure 17 Examples of sensors including stacked structure light emitting elements and photodetectors for red, green, and blue light are provided, but the color of light emitted from the stacked structure light emitting elements may be appropriately selected according to an object to be measured.

[0179] By placing light-emitting elements serving as light sources close to each other, a compact sensor can be obtained. OLED elements are suitable because they can be made small, light, and thin. At the same time, large areas of the human body surface need to be biomonitored. OLED elements can be easily manufactured on flat substrates to emit uniform light. In addition, OLED elements can be manufactured even on flexible substrates, so sensors using OLED elements can conform to large areas of the human body surface. In order to obtain higher sensitivity, the light intensity from the light source must be increased. To meet these demands on sensors, a configuration of stacked OLED elements with a charge generation layer separated between the stacked OLED elements is expected to be applied to the light source of the sensor.

[0180] As described above, the embodiments of the present invention have been described; however, the present invention is not limited to the aforementioned embodiments. Those skilled in the art can easily modify, add, or convert the various elements in the aforementioned embodiments within the scope of the present invention. A portion of the configuration of one embodiment may be replaced with the configuration of another embodiment, or the configuration of one embodiment may be incorporated into the configuration of another embodiment.

Claims

1. An OLED light-emitting device, comprising: an element separation layer having a plurality of openings defining a plurality of light emitting regions and a top surface between the openings; a plurality of lower electrodes, the plurality of lower electrodes being exposed in the opening, and the lower electrodes including a first lower electrode and a second lower electrode; a first stacked structure light emitting element, wherein the first stacked structure light emitting element is disposed on the first lower electrode; as well as a second stacked structure light emitting element, wherein the second stacked structure light emitting element is disposed on the second lower electrode adjacent to the first lower electrode, and the second stacked structure light emitting element is adjacent to the first stacked structure light emitting element; The first stacked structure light emitting element includes a first light emitting unit and a second light emitting unit stacked above the element separation layer, and a first charge generation layer located between the first light emitting unit and the second light emitting unit. Wherein, each of the first light-emitting unit and the second light-emitting unit includes a light-emitting layer, wherein the first charge generation layer is configured to supply charges of one polarity to the first light emitting unit and to supply charges of another polarity to the second light emitting unit, The second stacked structure light-emitting element includes a third light-emitting unit and a fourth light-emitting unit stacked above the element separation layer, and a second charge generation layer located between the third light-emitting unit and the fourth light-emitting unit. Wherein, each of the third light-emitting unit and the fourth light-emitting unit includes a light-emitting layer, wherein the second charge generation layer is configured to supply the charges of the one polarity to the third light emitting unit and to supply the charges of the other polarity to the fourth light emitting unit, wherein each of the first charge generation layer and the second charge generation layer is composed of one or more charge generation component layers, wherein the first end region of the first charge generation layer and the second end region of the second charge generation layer overlap above the top surface of the element separation layer, and In which, in the overlapping area of ​​the first end area and the second end area, the end area of ​​the first stacked structure light-emitting element or the second stacked structure light-emitting element, which is configured to block the component layer of charges of either polarity, is arranged between the charge generating component layer of the first charge generating layer and the second charge generating layer, which is configured to generate charges of either polarity.

2. The OLED light-emitting device according to claim 1, wherein: The component layer configured to block the charges of either polarity is a component layer of the first charge generation layer or the second charge generation layer configured to generate only charges of the opposite polarity to the either polarity.

3. The OLED light emitting device according to claim 1, wherein: The component layer configured to block charges of either polarity is a charge transport layer for charges of the opposite polarity to either polarity included in the component layers of the light emitting unit of the first stacked structure light emitting element or the second stacked structure light emitting element.

4. The OLED light-emitting device according to claim 1, in, The charge generation component layer configured to generate charges of either polarity generates charges of the opposite polarity to the either polarity in addition to the charges of the either polarity, and In which, in addition to the end region of the component layer configured to block the charges of either polarity being arranged between the charge generating component layers of the first charge generating layer and the second charge generating layer configured to generate charges of either polarity, the end region of the component layer configured to block the charges of the opposite polarity of the first stacked structure light-emitting element or the second stacked structure light-emitting element is also arranged between the charge generating component layers configured to generate charges of either polarity.

5. The OLED light-emitting device according to claim 1, in, The first charge generation layer is composed of a first charge generation composition layer configured to generate only charges of a first polarity and a second charge generation composition layer located above the first charge generation composition layer and configured to generate only charges of a second polarity, wherein the second charge generation layer is composed of a third charge generation composition layer configured to generate only charges of the first polarity and a fourth charge generation composition layer located above the third charge generation composition layer and configured to generate only charges of the second polarity, The overlapping region includes the first charge generation component layer, the second charge generation component layer, the third charge generation component layer, and the fourth charge generation component layer, which are arranged in order from the bottom. wherein the second charge generation composition layer between the first charge generation composition layer and the third charge generation composition layer blocks the charges of the first polarity, and The third charge generation composition layer between the second charge generation composition layer and the fourth charge generation composition layer blocks the charges of the second polarity.

6. The OLED light-emitting device according to claim 1, in, The first charge generation layer is composed of a first charge generation composition layer configured to generate charges of a first polarity and charges of a second polarity, and a second charge generation composition layer located above the first charge generation composition layer and configured to generate only charges of the second polarity, wherein the second charge generation layer is composed of a third charge generation composition layer configured to generate charges of the first polarity and charges of the second polarity, and a fourth charge generation composition layer located above the third charge generation composition layer and configured to generate charges of only the second polarity, The overlapping region includes the first charge generation component layer, the second charge generation component layer, the third charge generation component layer, and the fourth charge generation component layer, which are arranged in order from the bottom. wherein, in the overlapping region, an end region of the charge transport layer for the first polarity included in the constituent layers of the second stacked structure light emitting element is disposed between the second charge generation constituent layer and the third charge generation constituent layer, and The end region of the charge transport layer for the first polarity charge between the second charge generation composition layer and the third charge generation composition layer blocks the second polarity charge.

7. The OLED light-emitting device according to claim 1, in, The first charge generation layer is composed of a charge generation composition layer configured to generate charges of a first polarity and charges of a second polarity, wherein the second charge generating layer is composed of a charge generating component layer configured to generate charges of the first polarity and charges of the second polarity, wherein, in the overlapping region, an end region of the charge transport layer for charges of the second polarity of the first stacked structure light emitting element and an end region of the charge transport layer for charges of the first polarity of the second stacked structure light emitting element are arranged between the first charge generation layer and the second charge generation layer; wherein an end region of the charge transport layer for charges of the first polarity between the first charge generation layer and the second charge generation layer blocks charges of the second polarity, and The end region of the charge transport layer for charges of the second polarity between the first charge generation layer and the second charge generation layer blocks charges of the first polarity.

8. The OLED light emitting device according to claim 1, wherein: In the overlapping region, an end region of the light-emitting layer of the first stacked structure light-emitting element is disposed between the first charge generation layer and the second charge generation layer.

9. The OLED light emitting device according to claim 1, wherein: A first end region of the first charge generation layer and a second end region of the second charge generation layer are tapered above a top surface of the element separation layer.

10. The OLED light-emitting device according to claim 9, in, The first charge generation layer includes a third end region tapered in a first direction and a fourth end region tapered in a second direction perpendicular to the first direction, the third end region and the fourth end region being located above the top surface of the element separation layer, and The cone angle of the third end region is steeper than the cone angle of the fourth end region.

11. The OLED light-emitting device according to claim 1, in, Each of the first light emitting unit and the second light emitting unit includes a hole transport layer, and The end region of the hole transport layer is located above the top surface of the element separation layer.

12. The OLED light-emitting device according to claim 1, in, The first light emitting unit and the second light emitting unit are configured to emit light of a first color, wherein the third light emitting unit and the fourth light emitting unit are configured to emit light of a second color, Wherein, each of the first light-emitting unit and the second light-emitting unit includes a hole transport layer, Wherein, each of the third light-emitting unit and the fourth light-emitting unit includes a hole transport layer, and The hole transport layers of the first light-emitting unit and the second light-emitting unit are thicker than the hole transport layers of the third light-emitting unit and the fourth light-emitting unit.

13. A display device comprising the OLED light-emitting device according to 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, the method comprising: forming a plurality of lower electrodes; forming an element separation layer having a plurality of openings defining a plurality of light emitting regions and a top surface between the openings so that each lower electrode is exposed from the opening; forming a first stacked structure light emitting element and a second stacked structure light emitting element adjacent to each other on the element separation layer, The first stacked structure light emitting element includes a first light emitting unit and a second light emitting unit stacked above the element separation layer, and a first charge generation layer located between the first light emitting unit and the second light emitting unit. Wherein, each of the first light-emitting unit and the second light-emitting unit includes a light-emitting layer, wherein the first charge generation layer is configured to supply charges of one polarity to the first light emitting unit and to supply charges of another polarity to the second light emitting unit, The second stacked structure light-emitting element includes a third light-emitting unit and a fourth light-emitting unit stacked above the element separation layer, and a second charge generation layer located between the third light-emitting unit and the fourth light-emitting unit. Wherein, each of the third light-emitting unit and the fourth light-emitting unit includes a light-emitting layer, wherein the second charge generation layer is configured to supply the charges of the one polarity to the third light emitting unit and to supply the charges of the other polarity to the fourth light emitting unit, wherein each of the first charge generation layer and the second charge generation layer is composed of one or more charge generation component layers, wherein the first end region of the first charge generation layer and the second end region of the second charge generation layer overlap above the top surface of the element separation layer, and In which, in the overlapping area of ​​the first end area and the second end area, the end area of ​​the first stacked structure light-emitting element or the second stacked structure light-emitting element, which is configured to block the component layer of charges of either polarity, is arranged between the charge generating component layer of the first charge generating layer and the second charge generating layer, which is configured to generate charges of either polarity.

16. The method according to claim 15, further comprising: forming a first charge generation component layer of the first charge generation layer by vapor deposition using a metal mask placed in a first position; After forming the first charge generation component layer, placing the metal mask at a second position by moving the metal mask from the first position; as well as The second charge generation layer is formed of the same material as the first charge generation layer by vapor deposition using the metal mask placed at the second position.

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