Display device

Abstract

Provided is a display device comprising a plurality of light-emitting elements that are arranged in a matrix on a substrate and that radiate light having mutually different wavelengths. Each of the light-emitting elements has: a laminated structure comprising a lower electrode, a light-emitting layer provided on the lower electrode, an upper electrode provided on the light-emitting layer, and a protective film provided on the upper electrode; and a side wall film that covers the side surface of the laminated structure. In at least two light-emitting elements among the plurality of light-emitting elements, the film thickness of the light-emitting layer increases as the wavelength of light radiated from the light-emitting layer increases, the film thickness of the side wall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure with respect to the upper surface of the substrate increases as the wavelength of the light increases.

Description

display device

[0001] This disclosure relates to a display device.

[0002] In recent years, the development of display devices using electroluminescent (EL) elements as light-emitting elements has progressed. In such display devices, for example, multiple light-emitting elements, each having a stacked structure consisting of a lower electrode, a light-emitting layer stacked on the lower electrode, and an upper electrode stacked on the light-emitting layer, are arranged on a substrate. When a predetermined voltage is supplied to the lower electrode and the upper electrode, the light-emitting layer sandwiched between the lower electrode and the upper electrode emits light.

[0003] International Publication No. 2020 / 004086

[0004] In the manufacturing of display devices, a mask deposition process is used to sequentially deposit red, green, and blue light-emitting layers (RGB deposition), that is, to sequentially produce light-emitting elements that emit red, green, and blue light. However, in conventional manufacturing processes, the deposition of the light-emitting layer of the next light-emitting element is obstructed by the presence of previously produced light-emitting elements, making it difficult to uniformly laminate the light-emitting layers on the substrate.

[0005] Therefore, this disclosure proposes a technique that enables the uniform stacking of light-emitting layers of second and subsequent light-emitting elements.

[0006] According to this disclosure, a display device is provided comprising a plurality of light-emitting elements arranged in a matrix on a substrate and emitting light of different wavelengths from each other, wherein each light-emitting element has a laminated structure consisting of a lower electrode, a light-emitting layer provided on the lower electrode, an upper electrode provided on the light-emitting layer, and a protective film provided on the upper electrode, and a sidewall film covering the side surface of the laminated structure, wherein in at least two of the plurality of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases.

[0007] This is a schematic diagram showing an example of the overall configuration of a display device according to an embodiment of this disclosure. This is a schematic circuit diagram for explaining the wiring relationship in the sub-pixel of the mth row and nth column. This is a cross-sectional view for explaining an example of the pixel configuration according to a comparative example. This is a cross-sectional view (1) for explaining an example of the pixel manufacturing method according to a comparative example. This is a cross-sectional view (2) for explaining an example of the pixel manufacturing method according to a comparative example. This is a cross-sectional view for explaining the problems in the comparative example. This is a cross-sectional view (1) for explaining the pixel manufacturing method according to the first embodiment of this disclosure. This is a cross-sectional view (2) for explaining the pixel manufacturing method according to the first embodiment of this disclosure. This is a cross-sectional view (3) for explaining the pixel manufacturing method according to the first embodiment of this disclosure. This is a cross-sectional view (4) for explaining the pixel manufacturing method according to the first embodiment of this disclosure. This is a cross-sectional view for explaining an example of the pixel configuration according to the first embodiment of this disclosure. This is a cross-sectional view for explaining an example of the pixel configuration according to modification 1 of the first embodiment of this disclosure. This is a cross-sectional view for explaining an example of the pixel configuration according to modification 2 of the first embodiment of this disclosure. This is a cross-sectional view for explaining an example of the pixel configuration according to the second embodiment of this disclosure. This is a cross-sectional view for explaining an example of the pixel configuration according to the third embodiment of this disclosure. This is a cross-sectional view for explaining an example of the pixel configuration according to modification 3 of the third embodiment of this disclosure. This is a cross-sectional view illustrating an example of the pixel configuration according to the fourth embodiment of this disclosure. This is a plan view (1) illustrating an example of the pixel configuration according to the fifth embodiment of this disclosure. This is a plan view (2) illustrating an example of the pixel configuration according to the fifth embodiment of this disclosure. This is a plan view (3) illustrating an example of the pixel configuration according to the fifth embodiment of this disclosure. This is a plan view (4) illustrating an example of the pixel configuration according to the fifth embodiment of this disclosure. This is a cross-sectional view illustrating the background of the sixth embodiment of this disclosure. This is a cross-sectional view illustrating an example of the pixel configuration according to the sixth embodiment of this disclosure. This is a cross-sectional view illustrating an example of the pixel configuration according to a modified example of the sixth embodiment of this disclosure. This is a plan view illustrating the background of the seventh embodiment of this disclosure. This is a plan view illustrating an example of the pixel configuration according to the seventh embodiment of this disclosure.This is a plan view (1) illustrating an example of the pixel configuration according to a modification of the seventh embodiment of this disclosure. This is a plan view (2) illustrating an example of the pixel configuration according to a modification of the seventh embodiment of this disclosure. This is a plan view (3) illustrating an example of the pixel configuration according to a modification of the seventh embodiment of this disclosure. This is a plan view (4) illustrating an example of the pixel configuration according to a modification of the seventh embodiment of this disclosure. This is a conceptual diagram (1) illustrating the relationship between the normal LN passing through the center of the light-emitting part, the normal LN' passing through the center of the lens member, and the normal LN'' passing through the center of the wavelength selection part. This is a conceptual diagram (2) illustrating the relationship between the normal LN passing through the center of the light-emitting part, the normal LN' passing through the center of the lens member, and the normal LN'' passing through the center of the wavelength selection part. This is a conceptual diagram (part 3) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (part 4) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (part 5) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (part 6) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN" passing through the center of the wavelength-selecting part. This is a conceptual diagram (No. 7) illustrating the relationship between the normal vector LN passing through the center of the light-emitting part, the normal vector LN' passing through the center of the lens member, and the normal vector LN'' passing through the center of the wavelength selection part. This is a schematic cross-sectional view illustrating the first example of a resonator structure. This is a schematic cross-sectional view illustrating the second example of a resonator structure. This is a schematic cross-sectional view illustrating the third example of a resonator structure. This is a schematic cross-sectional view illustrating the fourth example of a resonator structure. This is a schematic cross-sectional view illustrating the fifth example of a resonator structure. This is a schematic cross-sectional view illustrating the sixth example of a resonator structure. This is a schematic cross-sectional view illustrating the seventh example of a resonator structure. This is a front view showing an example of the appearance of a digital still camera. This is a rear view showing an example of the appearance of a digital still camera. This is an external view of a head-mounted display. This is an external view of a see-through head-mounted display.This is an external view of a television system. This is an external view of a smartphone. This is a diagram (1) showing the internal configuration of a car. This is a diagram (2) showing the internal configuration of a car.

[0008] Preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configuration will be denoted by the same reference numeral to avoid redundant explanation. In addition, in this specification and drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding a different alphabet after the same reference numeral. However, if there is no particular need to distinguish each of multiple components having substantially the same or similar functional configurations, only the same reference numeral will be used.

[0009] Furthermore, the drawings referenced in the following description are intended to illustrate and facilitate understanding of one embodiment of this disclosure, and for the sake of clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from those of the actual product. In addition, the apparatus shown in the drawings may be modified in design as appropriate, taking into consideration the following description and known technology.

[0010] The descriptions of specific shapes in the following explanation do not refer only to geometrically defined shapes. More specifically, the descriptions of shapes in the following explanation include light-emitting elements, display devices (light-emitting devices), their manufacturing processes, and shapes that are similar to or have acceptable differences (errors or distortions) in their use and operation.

[0011] Furthermore, in the following descriptions of circuits (electrical connections), unless otherwise specified, "electrically connected" means connecting multiple elements in such a way that electricity (signals) can conduct through them. In addition, "electrically connected" in the following descriptions includes not only cases where multiple elements are directly and electrically connected, but also cases where they are indirectly and electrically connected through other elements.

[0012] The explanation will be given in the following order: 1. Overall configuration of the display device according to the embodiment of this disclosure 2. Background 3. First embodiment 3.1 Manufacturing method 3.2 Detailed configuration 3.3 Modification 4. Second embodiment 5. Third embodiment 5.1 Detailed configuration 5.2 Modification 6. Fourth embodiment 7. Fifth embodiment 8. Sixth embodiment 8.1 Background 8.2 Detailed configuration 8.3 Modification 9. Seventh embodiment 9.1 Background 9.2 Detailed configuration 9.3 Modification 10. Summary 11. Modification 11.1 Modification 1 11.2 Modification 2 12. Application examples 13. Supplement

[0013] <<1. Overall Configuration of the Display Device According to the Embodiment of the Disclosure>> Referring to Figure 1, an example of the overall configuration of an organic EL (Electro-Luminescence) display device (display device) 10 (hereinafter simply referred to as "display device 10") according to the embodiment of the disclosure, which is used as a display device or lighting device, will be described. Figure 1 is a schematic diagram showing an example of the overall configuration of the display device 10 according to the embodiment of the disclosure.

[0014] The display device 10 is a device in which light-emitting elements such as OLEDs (Organic Light Emitting Diodes) or Micro-OLEDs are formed in an array. Such a display device 10 can be applied as a display device for VR (Virtual Reality), MR (Mixed Reality), or AR (Augmented Reality), an electronic viewfinder (EVF), or a small projector, etc. The display device 10 can also be applied to various lighting devices. Note that the display device 10 may use light-emitting elements made of inorganic materials instead of light-emitting elements made of organic materials such as OLEDs.

[0015] The display device 10 has a display area (pixel array area) and a peripheral area provided around the periphery of the display area. As shown in Figure 1, within the display area of ​​the display device 10, for example, a plurality of subpixels 100R, 100G, and 100B are arranged in a matrix. For example, subpixel 100R can emit red light (for example, light with a wavelength of 580 nm to 640 nm), subpixel 100G can emit green light (for example, light with a wavelength of 510 nm to 550 nm), and subpixel 100B can emit blue light (for example, light with a wavelength of 450 nm to 480 nm). In the following description, when subpixels 100R, 100G, and 100B are not specifically distinguished, they will be referred to as subpixel 100.

[0016] Furthermore, in this embodiment, one pixel 20 is composed of, for example, three types of sub-pixels 100R, 100G, and 100B that emit different light. In this embodiment, the number and arrangement of each of the three types of sub-pixels 100R, 100G, and 100B included in one pixel 20 are not particularly limited. Also, a pixel 20 means the smallest unit (pixel) controlled when controlling the light emission of the display device 10, and is composed of a plurality of sub-pixels 100 that are treated as a single unit during control. In other words, in this embodiment, the display device 10 has a plurality of pixels 20 arranged in a matrix on the substrate 40.

[0017] Furthermore, as shown in Figure 1, a horizontal drive circuit 11 and a vertical drive circuit 12 are provided in the peripheral area of ​​the display device 10.

[0018] The horizontal drive circuit 11 scans each subpixel 100 row by row (in Figure 1, the direction extending along the X direction is called the row direction) when writing a signal to each subpixel, and each scan line SCL ｍ Scanning signals can be supplied sequentially. The horizontal drive circuit 11 can be configured, for example, by a shift register that sequentially shifts (transfers) start pulses in synchronization with the input clock pulses.

[0019] Further, the vertical drive circuit 12 supplies the signal voltage of a signal corresponding to the luminance information supplied from a signal source (not shown) to the sub-pixel 100 selected in units of columns (in FIG. 1, the direction extending along the Y direction is referred to as the column direction) via the signal line DTL. ｎ can be supplied.

[0020] In the embodiment of the present disclosure, the configuration of the display device 10 is not limited to the configuration shown in FIG. 1. That is, the configuration shown in FIG. 1 is merely an example, and the display device 10 according to the embodiment of the present disclosure may have various configurations.

[0021] Next, referring to FIG. 2, the circuit configuration of the sub-pixel 100 at the m-th row and n-th column will be described. FIG. 2 is a schematic circuit diagram for explaining the connection relationship of the sub-pixel 100 at the m-th row and n-th column.

[0022] In the display device 10, as described above, the sub-pixel 100 including the light-emitting element ELP is arranged in a two-dimensional matrix in a state of being connected to the scanning line SCL extending in the row direction (X direction in FIG. 1) and the signal line DTL extending in the column direction (Y direction in FIG. 1). ｍ and ｎ is connected to the signal line DTL extending in the column direction (Y direction in FIG. 1).

[0023] Further, as shown in FIG. 2, the display device 10 has a power supply line PS1 that supplies a drive voltage to the sub-pixel 100 ｍ and a common power supply line PS2 commonly connected to all the sub-pixels 100. A predetermined drive voltage V ｍ etc. is supplied to the power supply line PS1 from a power supply unit (not shown), and a common voltage V ｃｃ is supplied to the common power supply line PS2, and a common voltage V ｃａｔ (for example, ground potential) is supplied.

[0024] Here, let the number of the scanning lines SCL and the power supply lines PS1 be M each. The sub-pixels 100 in the m-th row (where m = 1, 2,..., P) are connected to the m-th scanning line SCL ｍ and the m-th power supply line PS1 ｍ and constitute one display element row. In FIG. 2, the scanning line SCL ｍAnd only the power supply line PS1m is shown. Also, the number of signal lines DTL is N. The subpixel 100 of the nth column (where n = 1, 2..., N) is the nth signal line DTL ｎ It is connected to the signal line DTL in Figure 2. ｎ Only the following is shown. Hereafter, the subpixel 100 located in the mth row and nth column may be referred to as the (n,m)th subpixel 100.

[0025] As explained earlier, the display device 10 is scanned sequentially row by row by the scanning signal from the horizontal drive circuit 11. More specifically, in the display device 10, M subpixels 100 arranged in the mth row are driven simultaneously. In other words, for the M subpixels 100 arranged along the row direction, the timing of their illumination / de-illumination is controlled on a row-by-row basis. For example, if the display frame rate of the display device 10 is FR (frames / second), the scanning period per row (the so-called horizontal scanning period) when the display device 10 is scanned sequentially row by row will be less than (1 / FR) × (1 / P) seconds.

[0026] Furthermore, as shown in Figure 2, the sub-pixel 100 is composed of a light-emitting element ELP and a drive circuit that drives it. The light-emitting element ELP consists of an organic electroluminescent light-emitting element or an inorganic electroluminescent light-emitting element. The drive circuit is a writing transistor TR Ｗ , and drive transistor TR Ｄ , and also, capacity section C １ It consists of the following: drive transistor TR Ｄ When current flows through the light-emitting element ELP, the ELP can emit light. Each transistor is composed of, for example, a p-channel field-effect transistor.

[0027] As shown in Figure 2, in the subpixel 100, the drive transistor TR Ｄ One of the source / drain regions is the capacitance section C １ One end and power supply line PS1 ｍ The source / drain region of the other side is electrically connected to one end of the light-emitting element ELP (specifically, the anode electrode).Ｄ The gate electrode is the writing transistor TR Ｗ It is connected to the other source / drain region, and the capacitance section C １ It is electrically connected to the other end.

[0028] Also, as shown in Figure 2, the writing transistor TR ｗ One of the source / drain regions is the signal line DTL ｎ It is electrically connected to the scan line SCL, and the gate electrode of the writing transistor TRw is connected to the scan line SCL. ｍ It is electrically connected to it.

[0029] Furthermore, as shown in Figure 2, the other end of the light-emitting element ELP (specifically, the cathode electrode) is electrically connected to the common power supply line PS2. In addition, a predetermined cathode voltage V is supplied to the common power supply line PS2. ｃａｔ This is supplied. Note that in Figure 2, the capacitance of the light-emitting element ELP is denoted by code C. ＥＬ It is represented as follows.

[0030] The overview of the driving of the subpixel 100 will be explained. In the subpixel 100, the signal line DTL is transmitted from the vertical drive circuit 12. ｎ With a voltage corresponding to the brightness of the image to be displayed supplied, the writing transistor TR is activated by a scanning signal from the horizontal drive circuit 11. ｗ When the capacitance C is in a conductive state, １ A voltage corresponding to the brightness is written to it. After the writing transistor TRw is made non-conductive, the capacitance part C １ The drive transistor TR operates according to the voltage held in Ｄ When an electric current flows through it, the light-emitting element ELP emits light.

[0031] In the embodiments of this disclosure, the configuration of the drive circuit that controls the light emission of the light-emitting element ELP is not limited to the configuration shown in Figure 2. Therefore, the configuration shown in Figure 2 is merely an example, and various configurations can be taken in the display device 10 according to the embodiments of this disclosure.

[0032] <<2. Background>> Next, before describing the details of the embodiments of this disclosure with reference to Figures 3 to 5, the present inventors will explain the background that led to the creation of the embodiments of this disclosure. Figure 3 is a cross-sectional view illustrating an example of the configuration of a pixel 20a according to a comparative example, and Figures 4A and 4B are cross-sectional views illustrating an example of a manufacturing method for a pixel 20a according to a comparative example. Furthermore, Figure 5 is a cross-sectional view illustrating the problems in the comparative example. Here, "comparative example" refers to the configuration and manufacturing method of a pixel 20a that the present inventors had been studying before creating the embodiments of this disclosure.

[0033] In recent years, light-emitting elements such as OLEDs have come to be used not only in direct-view display devices such as monitors, but also in ultra-small display devices (microdisplays) that require a pixel pitch of several microns. In direct-view display devices using OLEDs, the light-emitting elements of subpixels 100 are formed by sequentially creating light-emitting layers that emit blue, green, and red light, that is, by painting them separately with blue, green, and red (RGB painting) using the mask deposition process described above.

[0034] The comparative example display device 10 has a plurality of pixels 20a. In the comparative example, as shown in Figure 3, for example, each pixel 20a is composed of a combination of three types of subpixels 100R, 100G, and 100B. Here, subpixel 100R has a light-emitting element 112r that emits red light, subpixel 100G has a light-emitting element 112g that emits green light, and subpixel 100B has a light-emitting element 112b that emits blue light. In the comparative example, the number and arrangement of each of the three types of subpixels 100R, 100G, and 100B included in one pixel 20a are not limited. Also, in the comparative example, as shown in Figure 3, each light-emitting element 112b, 112g, and 112r are separated from each other.

[0035] Each light-emitting element 112 includes an anode electrode 200a provided on a substrate 40, a light-emitting layer 210 (specifically, light-emitting layers 210b, 210g, and 210r) laminated on the anode electrode 200a, a cathode electrode 220 laminated on the light-emitting layer 210 and transmitting light from the light-emitting layer 210, and a protective film 230 laminated on the cathode electrode 220 and transmitting light from the light-emitting layer 210. Furthermore, the sides of the light-emitting element 112 are covered by the protective film 232.

[0036] In the light-emitting element 112 according to this comparative example, when a predetermined voltage is supplied to the anode electrode 200a and the cathode electrode 220, the light-emitting layer 210 sandwiched between the anode electrode 200a and the cathode electrode 220 emits light. In the comparative example, light is emitted from the light-emitting layer 210 along the direction from the anode electrode 200a toward the cathode electrode 220. In other words, the display device 10 is a top-emission type light-emitting device.

[0037] In such a light-emitting element 112, it is required that the light-emitting layer 210 be uniformly laminated. If the light-emitting layer 210 is not uniformly formed on the anode electrode 200a, the light-emitting area of ​​the light-emitting element 112 (light-emitting area / element aperture) will be reduced, which may lead to a decrease in local brightness of the display device 10. Furthermore, if the light-emitting layer 210 is not uniformly formed on the anode electrode 200a, the reliability of the light-emitting element 112 may decrease due to the presence of areas where the light-emitting layer 210 is thin, which may shorten the product life of the display device 10.

[0038] Furthermore, in the comparative example, it is preferable to optimize the structure of the light-emitting element 112 so that the light extraction efficiency is improved for each color (wavelength) of emitted light. In the comparative example, as a method for such optimization, for example, microcavity technology (resonant structure) that achieves improved color reproducibility and light extraction efficiency is used.

[0039] In microcavity technology, for each light-emitting element 112, the distance between the anode electrode (first reflective surface) 200a, which functions as a reflective film, and the cathode electrode (second reflective surface) 220 is optimized to resonate the light from the light-emitting layer 210 between the anode electrode 200a and the cathode electrode 220. Specifically, in microcavity technology, for example, the optical distance L between the anode electrode 200a and the cathode electrode 220 satisfies the resonance condition shown by the following equation (1) with respect to the emission peak wavelength λ of the light-emitting layer 210.

[0040] λ: Emission peak wavelength λ of each subpixel 100 Φ: Phase shift (radians) between the first and second reflecting surfaces m: integer

[0041] Note that the resonance order m may differ for each of the 100 sub-pixels.

[0042] In such a microcavity structure, the optical distance L between the anode electrode 200a and the cathode electrode 220 corresponds to the thickness of the light-emitting layer 210. Therefore, in the comparative example, it is preferable to accurately and uniformly laminate the light-emitting layer 210 to achieve the desired thickness. Note that the optical distance is the distance that light travels through the medium (in this case, the light-emitting layer 210) converted to the distance that light travels in a vacuum.

[0043] Furthermore, each light-emitting element 112, which is assigned different colors of light such as red, green, and blue light, will emit light of a different color from its respective light-emitting layer 210. In order to realize a microcavity structure for improved color reproducibility and light extraction efficiency, it is preferable that each light-emitting layer 210 has a film thickness corresponding to the color of the light, i.e., the wavelength of the light. Therefore, in the comparative example, the film thickness of the light-emitting layer 210, and the height of the upper surface of each light-emitting element 112 relative to the upper surface of the substrate 40, will differ according to the corresponding color (wavelength) of light.

[0044] Furthermore, the pixel 20a in this comparative example is produced by a method using RGB color separation as shown in Figures 4A and 4B.

[0045] First, an anode electrode 200a is formed on the substrate 40. Next, the light-emitting layer 210a of the first light-emitting element 112a to be fabricated is laminated over the entire surface of the substrate 40 including the anode electrode 200a, for example, using a vapor deposition method. Then, the cathode electrode 220a of the first light-emitting element 112a to be fabricated is formed by depositing a film over the entire surface of the substrate 40, for example, by a sputtering method. Furthermore, a protective film 230 is deposited over the entire surface of the substrate 40, for example, by a CVD (Chemical Vapor Deposition) method. In this way, the configuration shown in the upper part of Figure 4A can be obtained.

[0046] Next, a resist (not shown) is formed on the protective film 230 so as to cover the areas that will become the second and third light-emitting elements 112c. Subsequently, the protective film 230, cathode electrode 220a, and light-emitting layer 210a are processed together along the resist pattern, for example by a dry etching method, and then the resist is removed to obtain the configuration shown in the lower part of Figure 4A. That is, the stacked structure of the first light-emitting element 112a is fabricated by the stage shown in the lower part of Figure 4A.

[0047] Next, a protective film 232 is formed to cover the sidewalls of the stacked structure of the first light-emitting element 112a using methods such as CVD and etching. In this way, the form shown in the upper part of Figure 4B can be obtained.

[0048] Furthermore, in the comparative example, in order to fabricate the stacked structure of the second light-emitting element 112c to be manufactured, for example, the light-emitting layer 210c of the second light-emitting element 112c to be manufactured is laminated over the entire surface of the substrate 40 using a vapor deposition method. In this way, the configuration shown in the lower part of Figure 4B can be obtained.

[0049] Furthermore, by repeating the same procedure as the stacked structure of the first light-emitting element 112a, the second light-emitting element 112c is fabricated, and the third light-emitting element 112 (not shown) is fabricated in sequence.

[0050] In the comparative example, since light-emitting elements 112 with different heights of their upper surfaces relative to the upper surface of the substrate 40 are fabricated sequentially, it is difficult to laminate the light-emitting layers 210c of the second and subsequent light-emitting elements 112c so that their film thickness is uniform.

[0051] Specifically, in the process shown in the lower part of Figure 4B, it is difficult to laminate the light-emitting layer 210c of the second light-emitting element 112c to be fabricated so that its film thickness is uniform. As can be seen from Figure 5, which is illustrated in more detail, when the light-emitting layer 210c is deposited, if the material of the light-emitting layer 210c diffuses without spreading widely from the front upper part of the anode electrode 200a of the light-emitting element 112c (small deposition angle) (arrow shown in the center of Figure 5), the light-emitting layer 210c is uniformly formed on the anode electrode 200a. However, if the material of the light-emitting layer 210c diffuses widely from the front upper part of the anode electrode 200a (large deposition angle) (arrow shown on the left side of Figure 5), the material of the light-emitting layer 210c is blocked by the tall light-emitting element 112a that was fabricated earlier. As a result, locally thin areas (vignetting) 300 occur in the light-emitting layer 210c, making it difficult to uniformly laminate the light-emitting layer 210c on the substrate 40. Furthermore, since the upper surface of the anode electrode 200a of the third light-emitting element 112c, which is adjacent to the light-emitting element 112a, is located at a much lower position than the upper surface of the first light-emitting element 112c, it is difficult to uniformly laminate the light-emitting layer 210c of the third light-emitting element 112c onto the substrate 40. Therefore, in the comparative example, it is difficult to laminate the light-emitting layers 210c of the second and subsequent light-emitting elements 112c so that their film thickness is uniform.

[0052] Furthermore, if the light-emitting layer 210c is not uniformly deposited on the anode electrode 200a, the presence of areas where the light-emitting layer 210c is thin (vignetting) 300 may reduce the reliability of the light-emitting element 112c and shorten the product life of the display device 10.

[0053] Therefore, in view of these circumstances, the present inventors have come up with an embodiment of the present disclosure that allows for the uniform stacking of the light-emitting layer 210c of the second and subsequent light-emitting elements 112c.

[0054] As explained earlier, since the light-emitting element 112 having a microcavity structure has light-emitting layers 210 with different thicknesses depending on the corresponding color (wavelength) of light, the height of the upper surface of the light-emitting element 112 relative to the upper surface of the substrate 40 will differ depending on the corresponding color (wavelength) of light. In the comparative example, the light-emitting elements 112 were fabricated in any order without considering that the light-emitting layers 210 have different thicknesses due to the microcavity structure.

[0055] Therefore, in this situation, the inventors focused on the difference in height of the light-emitting elements 112. If the upper surface of the light-emitting element 112 that was manufactured earlier is high, the material of the light-emitting layer 210 of the next light-emitting element 112 to be manufactured is obstructed, making vignetting 300 more likely to occur. Therefore, the inventors conceived the idea of ​​manufacturing the light-emitting elements 112 in order from the lowest height, that is, from the light-emitting elements 112 corresponding to shorter wavelengths of light. According to this idea, for example, if the display device 10 has light-emitting elements 112r, 112g, and 112b that emit red light, green light, and blue light, the blue light-emitting element 112b will be manufactured first, the green light-emitting element 112g will be manufactured next, and the red light-emitting element 112r will be manufactured last.

[0056] This method makes it less likely for the deposition of the light-emitting layer 210 of the next light-emitting element 112 to be hindered, or in other words, it becomes easier for the material of the light-emitting layer 210 to be deposited on the anode electrode 200 of the light-emitting element 112. As a result, vignetting 300 on the light-emitting layer 210 is suppressed, and the light-emitting layers 210 of the second and subsequent light-emitting elements 112 can be stacked so that their film thickness is uniform.

[0057] The present inventors will now describe in detail the embodiments of this disclosure they have created.

[0058] <<3. First Embodiment>> <3.1 Manufacturing Method> First, a method for manufacturing a pixel 20 (display device 10) according to the first embodiment of the present disclosure will be described with reference to Figures 6A to 6D. Figures 6A to 6D are diagrams for explaining the method for manufacturing a pixel 20 according to the present embodiment, and each step shows, in detail, a cross-section of the pixel 20 when it is cut along the film thickness direction of the substrate 40.

[0059] In this embodiment, the display device 10 has a plurality of pixels 20, similar to the comparative example. The pixels 20 are composed of a combination of three types of subpixels 100R, 100G, and 100B. Here, subpixel 100R has a light-emitting element 112r that emits red light, subpixel 100G has a light-emitting element 112g that emits green light, and subpixel 100B has a light-emitting element 112b that emits blue light. In this embodiment, the number and arrangement of the three types of light-emitting elements 112b, 112g, and 112r included in one pixel 20, as well as the color (wavelength) of the light, are not limited to the example described above.

[0060] In this embodiment as well, a mask deposition process is used to sequentially fabricate light-emitting elements 112b, 112g, and 112r that emit red, green, and blue light, and are separated from each other, by applying red, green, and blue paint (RGB painting). In this embodiment, the light-emitting elements 112 that emit short wavelengths are fabricated first, and the light-emitting elements 112 that emit long wavelengths are fabricated later. In this embodiment, for example, the light-emitting elements that emit blue light (first light-emitting element) 112b, the light-emitting elements that emit green light (second light-emitting element) 112g, and the light-emitting elements that emit red light (third light-emitting element) 112r are fabricated in that order.

[0061] First, in this embodiment, as shown in the upper part of Figure 6A, anode electrodes (first lower electrode, second lower electrode, third lower electrode) 200 are formed on the substrate 40. Specifically, for example, a metal film, a transparent conductive film, etc., can be deposited by sputtering, and then patterned using lithography and dry etching to form multiple anode electrodes 200.

[0062] Next, a light-emitting layer (first light-emitting layer) 210b that emits blue light is laminated over the entire surface of the substrate 40, including the anode electrode 200, for example using a vapor deposition method. Then, a transparent conductive material is deposited over the entire surface of the substrate 40 by sputtering as the cathode electrode (first upper electrode) 220b of the light-emitting element 112b. Furthermore, a protective film (first protective film) 240 made of a nitride film or the like is deposited over the entire surface of the substrate 40 by, for example, a CVD method. In this way, the configuration shown in the second row from the top of Figure 6A can be obtained.

[0063] Next, as shown in the third row from the top of Figure 6A, a resist 400 is formed to cover the portion of the protective film 240 that will become the light-emitting element 112b.

[0064] Next, as shown in the lower part of Figure 6A, the protective film 240, cathode electrode 220b, and light-emitting layer 210b are processed (divided) along the pattern of the resist 400 by dry etching, such as the RIE (Reactive Ion Etching) method, and then the resist 400 is removed. In this way, the stacked structure of the first light-emitting element 112b is fabricated.

[0065] Next, as shown in the upper part of Figure 6B, a protective film 240 is further laminated over the entire surface of the substrate 40, which includes the stacked structure of the light-emitting element 112b and the anode electrode 200, using, for example, CVD or ALD (Atomic Layer Deposition) methods.

[0066] Then, as shown in the second row from the top of Figure 6B, for example, by dry etching, the protective film 240 is removed from the areas where it is laminated on the top and sides of the laminated structure of the light-emitting element 112b, leaving the protective film 240 on the top and sides. In this way, the light-emitting element 112b is manufactured.

[0067] Next, as shown in the third row from the top in Figure 6B, a light-emitting layer (second light-emitting layer) 210g that emits green light, a cathode electrode (second upper electrode) 220g, and a protective film (second protective film) 240 are sequentially laminated on the entire surface of the substrate 40 including the anode electrode 200. The height of the upper surface of the light-emitting element 112b relative to the upper surface of the final substrate 40 is lower than that of the other light-emitting elements 112g and 112r. Therefore, in this embodiment, compared to the comparative example, the deposition of the light-emitting layer 210g of the light-emitting element 112g to be produced next is less likely to be hindered by the light-emitting element 112b produced earlier. Consequently, in this embodiment, the material for the light-emitting layer 210g is more easily deposited on the anode electrode 200 of the light-emitting element 112g. As a result, in this embodiment, vignetting 300 in the light-emitting layer 210g is suppressed, and the light-emitting layers 210g of the second and subsequent light-emitting elements 112g can be laminated so that their film thickness is uniform.

[0068] Next, as shown in the lower part of Figure 6B, a resist 402 is formed to cover the portion of the protective film 242 that will become the light-emitting element 112g.

[0069] Next, as shown in the upper part of Figure 6C, the protective film 242, cathode electrode 220g, and light-emitting layer 210g are processed together along the pattern of the resist 402, and then the resist 402 is removed. In this way, a stacked structure of the second light-emitting element 112g is fabricated.

[0070] Next, as shown in the second row from the top of Figure 6C, a protective film 242 is further laminated over the entire surface of the substrate 40, which includes the stacked structure of the light-emitting elements 112b and 112g and the anode electrode 200.

[0071] Then, as shown in the lower part of Figure 6C, the protective films 242 on the sides of the stacked structure of the light-emitting element 112b, and on the top and sides of the light-emitting element 112g are left intact, while the other protective films 242 are removed. In this way, the light-emitting element 112g is manufactured.

[0072] Next, using the same procedure as before, a red light-emitting layer (third light-emitting layer) 210r, a cathode electrode (third upper electrode) 220r, and a protective film (third protective film) 244 are sequentially laminated on the entire surface of the substrate 40 including the anode electrode 200. Furthermore, a resist (not shown) is formed to cover the area on the protective film 244 that will become the light-emitting element 112r. Subsequently, the protective film 244, cathode electrode 220r, and light-emitting layer 210r are processed together along the pattern of the resist, and then the resist is removed. In this way, the laminated structure of the second light-emitting element 112r is fabricated.

[0073] Then, a protective film 244 is further laminated over the entire surface of the substrate 40, which includes the laminated structure of light-emitting elements 112b, 112g, and 112r, using, for example, a CVD method. In this way, a third light-emitting element 112r is fabricated, as shown in the upper part of Figure 6D.

[0074] Furthermore, a resist (not shown) is formed with an opening that exposes the central upper surface portion of the light-emitting elements 112b, 112g, and 112r. Subsequently, as shown in the second row from the top in Figure 6D, a portion of the protective films 240, 242, and 244 is removed along the pattern of the resist to form an opening 250 that exposes the central upper surface portion of the cathode electrodes 220b, 220g, and 220r.

[0075] Then, a transparent conductive film, for example, which will form the wiring 252, is deposited. In this way, the configuration shown in the lower part of Figure 6D can be obtained.

[0076] Furthermore, the pixels 20 (display device 10) can be manufactured by patterning the wiring 252 or by forming on-chip lenses, etc. (not shown).

[0077] Thus, in this embodiment, since the light-emitting elements 112b, which corresponds to short wavelengths of light, are fabricated in order from the short-profile 112b to the taller 112g and 112r, which correspond to long wavelengths of light, the deposition of the light-emitting layers 210g and 210r of the light-emitting elements 112g and 112r that are fabricated next is less likely to be hindered by the light-emitting elements 112b that are fabricated first. Therefore, in this embodiment, the material for the light-emitting layers 210g and 210r is more easily deposited on the anode electrodes 200 of the second and subsequent light-emitting elements 112g and 112r. As a result, in this embodiment, vignetting 300 in the light-emitting layers 210g and 210r is suppressed, and the light-emitting layers 210g and 210r of the second and subsequent light-emitting elements 112g and 112r can be stacked so that their film thickness is uniform.

[0078] Furthermore, according to this embodiment, it is possible to suppress the decrease in reliability of the light-emitting elements 112g and 112r caused by the local thinning of the light-emitting layers 210g and 210r, and to avoid shortening the product life of the display device 10.

[0079] Furthermore, the pixels 20 (display device 10) according to this embodiment can be manufactured using methods, apparatus, and conditions commonly used in the manufacture of semiconductor devices. In other words, the pixels 20 (display device 10) according to this embodiment can be manufactured using existing semiconductor device manufacturing methods.

[0080] Examples of the methods mentioned above include PVD (Physical Vapor Deposition), CVD, and ALD. PVD methods include vacuum deposition, EB (electron beam) deposition, various sputtering methods (magnetron sputtering, RF (Radio Frequency)-DC (Direct Current) coupled bias sputtering, ECR (Electron Cyclotron Resonance) sputtering, opposing target sputtering, high-frequency sputtering, etc.), ion plating, laser ablation, molecular beam epitaxy (MBE (Molecular Beam Epitaxy)), and laser transfer. Furthermore, CVD methods include plasma CVD, thermal CVD, metal-organic (MO) CVD, and photo-CVD. Other methods include electrolytic plating, electroless plating, spin coating, immersion, casting, microcontact printing, drop casting, various printing methods such as screen printing, inkjet printing, offset printing, gravure printing, and flexographic printing, as well as stamping, spraying, air doctor coater, blade coater, rod coater, knife coater, squeeze coater, reverse roll coater, transfer roll coater, gravure coater, kiss coater, cast coater, spray coater, slit orifice coater, and calender coater. Patterning methods include chemical etching such as shadow masks, laser transfer, and photolithography, as well as physical etching using ultraviolet light or lasers. In addition, planarization techniques include CMP (Chemical Mechanical Polishing), laser planarization, and reflow.

[0081] Furthermore, this embodiment is not limited to the manufacturing method shown in Figures 6A to 6D.

[0082] <3.2 Detailed Configuration> Next, the detailed configuration of the pixel 20 according to the first embodiment of the present disclosure will be described with reference to Figure 7. Figure 7 is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to the present embodiment, and more specifically corresponds to a cross-section obtained when the substrate 40 is cut along its film thickness direction.

[0083] In this embodiment as well, pixels 20 are arranged in a matrix within the display area (pixel array) of the display device 10. As shown in Figure 7, the pixels 20 are composed of, for example, a combination of three types of subpixels 100R, 100G, and 100B. Here, subpixel 100R has a light-emitting element 112r that emits red light (for example, light with a wavelength of 580 nm to 640 nm), subpixel 100G has a light-emitting element 112g that emits green light (for example, light with a wavelength of 510 nm to 550 nm), and subpixel 100B has a light-emitting element 112b that emits blue light (for example, light with a wavelength of 450 nm to 480 nm). In this embodiment as well, the number and arrangement of the three types of subpixels 100B, 100G, and 100R (light-emitting elements 112b, 112g, and 112r) included in one pixel 20, and the color (wavelength) of the light, are not limited to the example described above.

[0084] Furthermore, in this embodiment, as shown in Figure 7, each light-emitting element 112b, 112g, and 112r is separated from each other. Each light-emitting element 112 has a laminated structure consisting of an anode electrode (lower electrode) 200 provided on a substrate 40, a light-emitting layer 210 (specifically, light-emitting layers 210b, 210g, and 210r) laminated on the anode electrode 200, a cathode electrode (upper electrode) 220 (specifically, cathode electrodes 220b, 220g, and 220r) laminated on the light-emitting layer 210, and protective films 240, 242, and 244 laminated on the cathode electrode 220. In addition, the sides of the laminated structure of each light-emitting element 112 are covered by sidewall films consisting of protective films 240, 242, and 244.

[0085] Furthermore, in this embodiment, the height H of the upper surface of the stacked structure of each light-emitting element 112 relative to the upper surface of the substrate 40 is ｂ H ｇ H ｒThis varies depending on the color (wavelength) of the light corresponding to the light-emitting element 112 in order to realize a microcavity structure. More specifically, in this embodiment, the height H of the stacked structure of the light-emitting element 112r corresponds to long wavelength light. ｒ The height H of the stacked structure of the light-emitting element 112g corresponds to the highest and second longest wavelength light. ｇ The next highest is H of the stacked structure of the light-emitting element 112b corresponding to short wavelength light. ｂ This is the lowest. Below, the details of each component of these light-emitting elements 112 will be described in order.

[0086] The substrate 40 can be formed from a transparent material such as glass or a semiconductor material such as silicon. For example, a drive circuit for driving the light-emitting element 112 can be constructed by appropriately forming transistors, wiring, etc., within the substrate 40. An anode electrode 200, which will be described later, is provided on the substrate 40. For example, a voltage can be applied to the anode electrode 200 via a via (not shown) provided on the substrate 40.

[0087] In detail, the substrate 40 can be formed from a glass substrate such as high-strain point glass, soda glass, borosilicate glass, forsterite, lead glass, or quartz glass; a semiconductor substrate such as amorphous silicon or polycrystalline silicon; or a resin substrate such as polymethyl methacrylate, polyvinyl alcohol, polyvinylphenol, polyethersulfone, polyimide, polycarbonate, polyethylene terephthalate, or polyethylene naphthalate.

[0088] In this embodiment, the anode electrode 200 of each light-emitting element 112 is provided on the substrate 40 individually for each light-emitting element 112, that is, separated. When a voltage is applied between the anode electrode 200 and the cathode electrode 220 (described later), holes are injected from the anode electrode 200 into the light-emitting layer 210 (described later). Furthermore, in this embodiment, the film thickness of the anode electrode 200 of each light-emitting element 112b, 112g, and 112r may be the same.

[0089] Preferably, the anode electrode 200 has not only the function of an electrode but also the function of a reflective layer. In such cases, it is preferable for the anode electrode to be made of a metal film that has as high a reflectivity as possible and a large work function in order to improve the efficiency of light extraction. Therefore, in this embodiment, it is preferable that the anode electrode 200 be formed from a metal film having the above-mentioned properties. Examples of such metal films include metal films containing at least one of the elements and alloys of metals such as chromium (Cr), gold (Au), platinum (Pt), nickel (Ni), copper (Cu), molybdenum (Mo), titanium (Ti), tantalum (Ta), aluminum (Al), magnesium (Mg), iron (Fe), tungsten (W), and silver (Ag). Specific examples of the above alloys include aluminum (Al) alloys such as AlNi alloy or AlCu alloy, and silver (Ag) alloys such as MgAg alloy.

[0090] Furthermore, the outermost surface of the anode electrode 200 may be covered with a transparent conductive film. More specifically, the upper surface of the anode electrode 200 of the light-emitting element 112 may be covered with a transparent conductive film. By making the surface of the anode electrode 200 that is in contact with the light-emitting layer 210 a transparent conductive film, it is possible to maintain high conductivity while increasing adhesion with the light-emitting layer 210. Furthermore, by appropriately selecting the material of the transparent conductive film, the hole injection barrier to the light-emitting layer 210 can be lowered in terms of work function, and the driving voltage of the display device 10 can be lowered. Moreover, even if the outermost surface of the anode electrode 200 is rough due to damage during the manufacturing process, the surface can be flattened by covering it with a transparent conductive film. In this way, the light-emitting layer 210 laminated on the anode electrode 200 can be made into a higher quality film.

[0091] In this embodiment, the transparent conductive film may include, for example, at least one selected from the group consisting of transparent conductive oxides containing indium (In) (hereinafter referred to as "indium-based transparent conductive oxide"), transparent conductive oxides containing tin (Sn) (hereinafter referred to as "tin-based transparent conductive oxide"), and transparent conductive oxides containing zinc (Zn) (hereinafter referred to as "zinc-based transparent conductive oxide").

[0092] Indium-based transparent conductive oxides include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), indium gallium zinc oxide (IGZO), or fluorine-doped indium oxide (IFO). Tin-based transparent conductive oxides include, for example, tin oxide, antimond-doped tin oxide (ATO), or fluorine-doped tin oxide (FTO). Zinc-based transparent conductive oxides include, for example, zinc oxide, aluminum-doped zinc oxide (AZO), boron-doped zinc oxide, or gallium-doped zinc oxide (GZO).

[0093] In this embodiment, the light-emitting layer 210 is formed on the anode electrode 200 and emits one of three colors of light, for example, red light (peak wavelength of, for example, 580 nm to 640 nm), green light (peak wavelength of, for example, 510 nm to 550 nm), and blue light (peak wavelength of, for example, 450 nm to 480 nm). In this embodiment, the light-emitting layer 210 may be a light-emitting layer that emits light of a color other than these. Furthermore, in the following description, the light-emitting element 112 according to this embodiment will be described as having a light-emitting layer 210 made of an organic material as a light-emitting part (i.e., the light-emitting element 112 is an OLED), but this embodiment is not limited to this. For example, in this embodiment, the light-emitting element 112 may have a light-emitting layer 210 made of an inorganic material.

[0094] Furthermore, in this embodiment, as shown in Figure 7, the light-emitting layer 210 is provided individually for each light-emitting element 112, i.e., separated, similar to the comparative example. In addition, in this embodiment, in order to realize a microcavity structure, the thickness of the light-emitting layer 210 increases as the wavelength of the corresponding light increases. In this embodiment, for example, the light-emitting layer 210r of the light-emitting element 112r has the thickest thickness, the light-emitting layer 210g of the light-emitting element 112g has the next thickest thickness, and the light-emitting layer 210b of the light-emitting element 112b has the thinnest thickness.

[0095] More specifically, in this embodiment, for example, the distance between the anode electrode (first reflective surface) 200, which functions as a reflective film, and the cathode electrodes (second reflective surfaces) 220b, 220g, and 220r, i.e., the optical distance L corresponding to the film thickness of each light-emitting layer 210b, 210g, and 210r, is set to satisfy the following formula (1) according to the emission peak wavelength λ of each light-emitting layer 210b, 210g, and 210r. In this way, a microcavity structure can be realized. However, in this embodiment, the integer m is assumed to be the same integer for all light-emitting layers 210b, 210g, and 210r. As explained earlier, the optical distance is the distance that light travels through the medium (in this case, the light-emitting layer 210) converted to the distance that light travels in a vacuum.

[0096] λ: Emission peak wavelength λ of each emission layer 210 Φ: Phase shift (radians) between the first and second reflecting surfaces m: integer

[0097] In this embodiment, for example, a reflective film (not shown) that functions as the first reflective surface may be provided below the anode electrode 200. That is, in this embodiment, the first and second reflective surfaces are not limited to the anode electrode 200 and the cathode electrode 220. In such a case, the optical distance L is the distance between the layer that functions as the first reflective surface and the layer that functions as the second reflective surface.

[0098] More specifically, the light-emitting layer 210 has a structure in which, for example, a hole injection layer, a hole transport layer, light-emitting layers of each color, and an electron transport layer are sequentially stacked from bottom to top in the figure. Here, each light-emitting layer of the same color may be a multilayer structure in which different light-emitting materials that emit light of the same color are stacked. By layering light-emitting materials with different properties and separating their functions, localized degradation within the light-emitting layer is suppressed, and a highly efficient and long-life device can be obtained.

[0099] The hole-injection layer can be composed of, for example, hexaazatriphenylene (HAT).

[0100] The hall transport layer can be composed of, for example, α-NPD[N,N'-di(1-naphthyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine].

[0101] The red light-emitting layer generates red light when an electric field is applied, as a portion of the holes injected from the anode electrode 200 via the hole injection layer and hole transport layer recombine with a portion of the electrons injected from the cathode electrode 220 via the electron transport layer. The red light-emitting layer includes, for example, at least one of the following: a red light-emitting material, a hole transport material, an electron transport material, and a dual charge transport material. The red light-emitting material may be fluorescent or phosphorescent. Specifically, the red light-emitting layer can be composed of, for example, 4,4-bis(2,2-diphenylbinin)biphenyl (DPVBi) mixed with 30% by weight of 2,6-bis[(4'-methoxydiphenylamino)styryl]-1,5-dicyanonaphthalene (BSN).

[0102] The blue light-emitting layer generates blue light when an electric field is applied, as some of the injected holes and some of the injected electrons recombine. The blue light-emitting layer includes, for example, at least one of the following: a blue light-emitting material, a hole-transporting material, an electron-transporting material, and a dual-charge-transporting material. The blue light-emitting material may be fluorescent or phosphorescent. Specifically, the blue light-emitting layer can be composed of, for example, a mixture of DPVBi and 2.5% by weight of 4,4'-bis[2-{4-(N,N-diphenylamino)phenyl}vinyl]biphenyl (DPAVBi).

[0103] The green light-emitting layer generates green light when an electric field is applied, as some of the injected holes and some of the injected electrons recombine. The green light-emitting layer includes, for example, at least one of the following: a green light-emitting material, a hole-transporting material, an electron-transporting material, and a dual-charge-transporting material. The green light-emitting material may be fluorescent or phosphorescent. Specifically, the green light-emitting layer can be composed of, for example, a mixture of DPVBi and 5% by weight of coumarin 6.

[0104] Examples of electron transport layers include BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Alq3 (aluminum quinolinol), and Bphen (basophenanthroline). The electron transport layer consists of at least one layer and may include an electron transport layer doped with an alkali metal or alkaline earth metal.

[0105] An electron transport layer doped with an alkali metal or alkaline earth metal can be constructed by co-depositing, for example, 0.5 to 15% by weight, of an alkali metal such as lithium (Li), sodium (Na), potassium (K), rubidium (Rb), or cesium (Cs), or an alkaline earth metal such as magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba), as a host material.

[0106] Furthermore, an electron injection layer may be provided between the electron transport layer and the cathode electrode 220. The electron injection layer is for increasing electron injection from the cathode and can be composed of an alkali metal or alkaline earth metal in its elemental form, a compound containing them, or a mixture containing them. For example, the electron injection layer can be composed of lithium (Li) or lithium fluoride (LiF), etc.

[0107] Furthermore, a buffer layer may be provided between the electron transport layer and the cathode electrode 220. The buffer layer is intended to mitigate process damage during film formation of the cathode electrode 220. The buffer layer may be made of, for example, Mg, magnesium silver alloy (MgAg), Ca, Li, LiF, lithium carbonate (Li ２ CO ３ ), Cs, Cesium carbonate (Cs ２ CO ３ It can be composed of elements of alkali metals or alkaline earth metals, compounds containing them, or mixtures containing them.

[0108] The cathode electrode 220 is provided on the light-emitting layer 210. The cathode electrode 220, like the anode electrode 200, is provided individually for each light-emitting element 112, i.e., separated. When a voltage is applied between the anode electrode 200 and the cathode electrode 220, electrons are injected from the cathode electrode 220 into the light-emitting layer 210.

[0109] The cathode electrode 220 is preferably made of a transparent conductive material that has good light transmittance to visible light (for example, visible light with wavelengths of about 360 nm to 780 nm) and a small work function. For example, the cathode electrode 220 can be formed from a metal film containing at least one of the elements and alloys of metals such as aluminum (Al), magnesium (Mg), calcium (Ca), sodium (Na), and silver (Ag). Specific examples of alloys include aluminum (Al) alloys such as MgAg alloy or AlLi alloy, and silver (Ag) alloys. Furthermore, the cathode electrode 220 may be made from a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO). The cathode electrode 220 may be made of a laminated film of a metal layer and a conductive oxide layer. Furthermore, if the cathode electrode 220 is made of a multilayer film, the metal layer may be provided on the light-emitting layer 210 side, or the transparent conductive oxide layer may be provided on the light-emitting layer 210 side.

[0110] The protective films 240, 242, and 244 are provided to prevent the light-emitting layer 210 and the like from being damaged during the manufacturing process or contaminated by the external environment. The protective films 240, 242, and 244 are preferably formed from, for example, inorganic and organic materials that have low hygroscopicity and light transmittance to visible light. Furthermore, the protective films 240, 242, and 244 may have a single-layer structure or a multi-layer structure. For example, as an inorganic material, silicon oxide (SiO₂) may be used. ｘ ), silicon nitride (SiN ｘ ), silicon oxide nitride (SiO ｘ Ny), Titanium Oxide (TiO ｘ ) and aluminum oxide (AlO ｘ Examples of organic materials include thermosetting resins and photosensitive resins. Photosensitive resins include, for example, ultraviolet curable resins. Specifically, examples of organic materials include acrylic resins, polyimide resins, novolac resins, epoxy resins, norbornene resins, and parylene resins. Furthermore, protective films 240, 242, and 244 may be ALD (Atomic Layer Deposition) layers to enhance the effect of suppressing moisture penetration.

[0111] In this embodiment, the total film thickness J of the protective films 240, 242, and 244 on the cathode electrode 220, which are located on the upper side of the stacked structure of each light-emitting element 112. ｂ J ｇ J ｒ These may be different from each other, or they may be the same. Specifically, in this embodiment, as shown in Figure 7, for example, the total film thickness J of the protective films 240 and 244 on the cathode electrode 220b of the light-emitting element 112b. ｂ And the total film thickness J of the protective films 242 and 244 on the cathode electrode 220g of the light-emitting element 112g. ｇ and light-emitting element 112 ｒ The thickness J of the protective film 244 on the cathode electrode 220b ｒThis may be the same. By doing so, it becomes easy to uniformly create openings 250 (see Figure 10) in the protective films 240, 242, and 244 on each cathode electrode 220, exposing a portion of the upper surface of each cathode electrode 220.

[0112] Furthermore, in this embodiment, as shown in Figure 7, the thickness of the sidewall film covering the sides of the stacked structure of each light-emitting element 112 varies depending on the color (wavelength) of the light emitted by the light-emitting element 112, becoming thinner as the wavelength of light increases. Moreover, in this embodiment, as shown in Figure 7, the number of layers constituting the sidewall film covering the sides of the stacked structure of each light-emitting element 112 varies depending on the color (wavelength) of the light emitted by the light-emitting element 112, becoming thinner as the wavelength of light increases. More specifically, in this embodiment, for example, the sidewall film of the light-emitting element 112b with the shortest wavelength of light is the thickest and consists of three layers: protective films 240, 242, and 244. Also in this embodiment, the sidewall film of the light-emitting element 112g with the next shortest wavelength of light is the next thickest and consists of two layers: protective films 242 and 244. Furthermore, in this embodiment, the sidewall film of the light-emitting element 112r with the longest wavelength of light is the thinnest and consists of one layer: protective film 244. In this context, the thickness of the sidewall film refers to the thickness of the portion of the film that makes up the sidewall film that covers the side surface of the laminated structure of the light-emitting element 112.

[0113] Furthermore, in this embodiment, as shown in Figure 7, the cross-section of each light-emitting element 112, cut along the stacking direction of its stacked structure, has a tapered shape that widens from the top surface to the bottom surface of the stacked structure. In this embodiment, the taper angle A of the above cross-section of each light-emitting element 112 ｂ A ｇ A ｒ The angle varies depending on the color (wavelength) of the light emitted by the light-emitting element 112, and decreases as the wavelength of light increases. More specifically, in this embodiment, the taper angle A of the cross-section of the light-emitting element 112b with the shortest wavelength of light. ｂ The angle is the largest, and the next shortest wavelength of light is the tapered angle A of the cross-section of the light-emitting element 112b. ｇ The angle is the next largest. Furthermore, in this embodiment, the taper angle A of the cross-section of the light-emitting element 112r with the longest wavelength of light. ｒThe angle is the smallest.

[0114] As described above, in this embodiment, since the light-emitting elements 112b, which are low in height and correspond to short wavelengths of light, are manufactured in order from the taller light-emitting elements 112g and 112r, which correspond to long wavelengths of light, the pixels 20 will have a shape as shown in the example in Figure 7 above. Furthermore, in this embodiment, by manufacturing in this manner, the deposition of the light-emitting layers 210g and 210r of the light-emitting elements 112g and 112r, which are manufactured next, is less likely to be hindered by the light-emitting element 112b, which is manufactured first.Therefore, in this embodiment, the material for the light-emitting layers 210g and 210r is more easily deposited on the anode electrodes 200 of the second and subsequent light-emitting elements 112g and 112r.As a result, in this embodiment, vignetting 300 in the light-emitting layers 210g and 210r is suppressed, and the light-emitting layers 210g and 210r of the second and subsequent light-emitting elements 112g and 112r can be stacked so that their film thickness is uniform.

[0115] Furthermore, according to this embodiment, it is possible to suppress the decrease in reliability of the light-emitting elements 112g and 112r caused by the local thinning of the light-emitting layers 210g and 210r, and to avoid shortening the product life of the display device 10.

[0116] In this embodiment, the pixel 20 is not limited to the form shown in Figure 7, but can be transformed into various forms.

[0117] <3.3 Modifications> (Modification 1) Next, with reference to Figure 8A, the detailed configuration of the pixel 20 according to Modification 1 of this embodiment will be described. Figure 8A is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to Modification 1 of this embodiment, and in detail corresponds to a cross-section when the substrate 40 is cut along its film thickness direction.

[0118] In this modified example 1, as shown in Figure 8A, a planarization film 260 is provided so as to cover the stacked structure of each light-emitting element 112. Furthermore, in this modified example 1, a color filter 262, a planarization film 264, and an on-chip lens 266 are provided on the planarization film 260.

[0119] The planarization films 260 and 264 can be formed from, for example, inorganic insulating materials such as silicon nitride, silicon oxide, or silicon oxynitride, or organic resin materials such as acrylic resins or polyimide resins. Furthermore, the planarization films 260 and 264 may be single-layer films or multi-layer films of the aforementioned materials.

[0120] The color filter 262 is a filter that transmits light emitted from the light-emitting layer 210 of the corresponding light-emitting element 112. For example, the color filter 262 can be a color filter 262r that transmits red light, a color filter 262g that transmits green light, or a color filter 262b that transmits blue light. The color filter 262 can be formed from a material in which a pigment or dye is dispersed in a transparent binder such as silicone. In this modified example 1, the color filter 262 may not be provided.

[0121] The on-chip lens 266 can emit light from the light-emitting layer 210 as collimated light, either directly above or diagonally above the light-emitting element 112. The on-chip lens 266 can be formed from, for example, a styrene resin, an acrylic resin, a styrene-acrylic copolymer resin, or a siloxane resin.

[0122] In this embodiment, instead of the on-chip lens 266, a lens structure capable of guiding light in a desired direction may be used. Examples of such lens structures include metasurfaces and waveguides. Here, a metasurface refers to a structure in which structures smaller than the wavelength of light are periodically arranged in two dimensions, and can be formed from, for example, metal or dielectric material. Furthermore, when using a metasurface, it is not limited to being provided for each light-emitting element 112 (sub-pixel 100), but may be provided so as to span multiple light-emitting elements 112.

[0123] Furthermore, in this modified example 1, the positions of the center of the light-emitting layer 210, the center of the color filter 262, and the center of the on-chip lens 266 may be the same or different. Furthermore, in this modified example 1, the amount of deviation between the center of the light-emitting layer 210, the center of the color filter 262, and the center of the on-chip lens 266 may differ depending on the position of the light-emitting element 112 in the display area (pixel array portion) of the display device 10. For example, the amount of deviation may be larger for light-emitting elements 112 located closer to the outer edge of the display area. Details of such deviations will be described later.

[0124] (Modification 2) Next, with reference to Figure 8B, the detailed configuration of the pixel 20 according to Modification 2 of this embodiment will be described. Figure 8B is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to Modification 2 of this embodiment, and in detail corresponds to a cross-section when the substrate 40 is cut along its film thickness direction.

[0125] In the embodiment described above, the light-emitting elements 112b, 112g, and 112r are manufactured sequentially. As can be seen from Figures 6A to 6C, the anode electrodes 200 of the second and subsequent light-emitting elements 112g and 112r are subjected to multiple processing steps and are therefore susceptible to damage. To suppress the damage to the anode electrodes 200 of the second and subsequent light-emitting elements 112g and 112r that occurs during manufacturing, in this modified example 2, an anode protective film (lower electrode protective film) 280 is provided to cover a part of the anode electrode 200.

[0126] In detail, in this modified example 2, after each anode electrode 200 is first fabricated, an anode protective film 280 is fabricated to cover the anode electrode 200. The anode protective film 280 covers the anode electrode 200 during the fabrication of the pixel 20, thereby suppressing damage to the anode electrode 200 due to various processing treatments. Furthermore, as described above, various treatments are performed to sequentially fabricate the light-emitting element 112b, light-emitting element 112g, and light-emitting element 112r. At this time, the portion of the anode protective film 280 located in the center of the upper surface of the anode electrode 200 is etched. Furthermore, because it is exposed to various treatments, the portion of the anode protective film 280 covering the outer circumference of the anode electrode 200 also becomes thinner depending on the conditions, number of treatments, and duration of such treatments. Therefore, in this modified example 2, the thickness of the anode protective film 280 becomes thinner with each subsequent light-emitting element 112. In other words, in this modified example 2, the thickness of the anode protective film 280 decreases as the wavelength of light from the light-emitting element 112 increases.

[0127] More specifically, in this modified example 2, for example, as shown in Figure 8B, the thickness of the anode protective film 280b is thickest for the first light-emitting element 112b with the shortest wavelength of light, and the thickness of the anode protective film 280g for the second light-emitting element 112g with the next shortest wavelength of light is the next thickest. Furthermore, in this modified example 2, the thickness of the anode protective film 280r for the third light-emitting element 112r with the longest wavelength of light is the thinnest.

[0128] As described above, in this modified example 2, by providing an anode protective film 280 that covers the anode electrode 200, damage to the anode electrode 200 due to various processing treatments during manufacturing can be suppressed.

[0129] <<4. Second Embodiment>> Next, with reference to Figure 9, the detailed configuration of the pixel 20 according to the second embodiment of the present disclosure will be described. Figure 9 is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to this embodiment, and more specifically corresponds to a cross-section obtained when the substrate 40 is cut along its film thickness direction.

[0130] In the first embodiment of the present disclosure described above, by sequentially manufacturing the low-profile light-emitting element 112b corresponding to short wavelength light, and then the taller light-emitting elements 112g and 112r corresponding to long wavelength light, the light-emitting layers 210g and 210r of the second and subsequent light-emitting elements 112g and 112r can be stacked so that their film thickness is uniform. Furthermore, in the second embodiment of the present disclosure, the light-emitting area (element aperture) of the light-emitting element 112 in a plan view (when the light-emitting element 112 is viewed from above the substrate 40) is made smaller as the wavelength of the corresponding light increases. In this embodiment, by doing so, the distance between the previously manufactured light-emitting element 112b and the anode electrode 200 of the second and subsequent light-emitting elements 112g and 112r is increased. Therefore, according to this embodiment, the obstruction of the material of the light-emitting layers 210g and 210r of the second and subsequent light-emitting elements 112g and 112r by the previously manufactured light-emitting element 112b is further suppressed. Therefore, according to this embodiment, the light-emitting layers 210g and 210r of the second and subsequent light-emitting elements 112g and 112r can be laminated with a more uniform film thickness.

[0131] More specifically, in this embodiment, for example, as shown in Figure 9, the area (element aperture) L of the first light-emitting element 112b with the shortest wavelength of light is ｂ The area (element aperture) L of the light-emitting element 112g, which has the largest and second shortest wavelength of light, is the largest. ｇ The next largest is the area (element aperture) L of the third light-emitting element 112r that is manufactured and has the longest wavelength of light. ｒ This is the smallest. Generally, the product life of the light-emitting element 112 is longest for the red light-emitting element 112r, followed by the green light-emitting element 112g, and shortest for the blue light-emitting element 112b. Therefore, even if the area size of the light-emitting element 112 is as described above, it has little effect on the overall product life of the display device 10.

[0132] As described above, in this embodiment, the area (element aperture) of the light-emitting element 112 is made smaller as the wavelength of the corresponding light increases. By doing so, according to this embodiment, the light-emitting layers 210g and 210r of the second and subsequent light-emitting elements 112g and 112r can be laminated with a more uniform film thickness.

[0133] In this embodiment, the pixel 20 is not limited to the form shown in Figure 9, but can be transformed into various forms.

[0134] <<5. Third Embodiment>> <5.1 Detailed Configuration> Next, with reference to Figure 10, the detailed configuration of the pixel 20 according to the third embodiment of the present disclosure will be described. Figure 10 is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to this embodiment, and more specifically corresponds to a cross-section obtained when the substrate 40 is cut along its film thickness direction.

[0135] In this embodiment, as shown in Figure 10, the protective films 240, 242, and 244 have openings (contact holes) 250 that expose the central part of the upper surface of the cathode electrode 220. Furthermore, the wiring 252 extends to cover at least a portion of the inner wall of the opening 250, and further extends to cover at least a portion of the upper surface of the protective films 242 and 244. In addition, the wiring 252 contacts the cathode electrode 220 exposed through the opening 250, thereby electrically connecting the cathode electrodes 220 of adjacent light-emitting elements 112.

[0136] The wiring 252 can be formed from, for example, a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO). Furthermore, the wiring 252 may be composed of, for example, a metal layer, or a metal layer and a transparent conductive oxide layer.

[0137] Furthermore, in this embodiment, the opening 250 may be filled with a high refractive index material (not shown) having a higher refractive index than the protective films 240, 242, and 244. Examples of high refractive index materials include titanium oxide (TiO2). ｘ ) and other oxide films, silicon nitride (SiN ｘNitride films such as silicon oxynitride (SiO ｘ N ｙ Examples include resin materials such as epoxy resins. In this embodiment, by embedding such a high refractive index material in the opening 250, light can be efficiently extracted to the front and above the light-emitting element 112.

[0138] In this embodiment, the total film thickness J of the protective films 240, 242, and 244 on the cathode electrode 220, which is located above the stacked structure of each light-emitting element 112, is also specified. ｂ J ｇ J ｒ It is preferable that these are the same. Specifically, in this embodiment, as shown in Figure 10, for example, the total film thickness J of the protective films 240 and 244 on the cathode electrode 220b of the light-emitting element 112b. ｂ And the total film thickness J of the protective films 242 and 244 on the cathode electrode 220g of the light-emitting element 112g. ｇ and light-emitting element 112 ｒ The thickness J of the protective film 244 on the cathode electrode 220b ｒ This may be the same as the other. In this embodiment, it is easy to uniformly create openings 250 in the protective films 240, 242, and 244 on each cathode electrode 220 that expose a part of the upper surface of each cathode electrode 220.

[0139] In this embodiment, the pixel 20 is not limited to the form shown in Figure 10, but can be transformed into various forms.

[0140] <5.2 Modified Examples> Next, with reference to Figure 11, the detailed configuration of the pixel 20 according to a modified example of this embodiment will be described. Figure 11 is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to a modified example of this embodiment, and more specifically, it corresponds to a cross-section obtained when the substrate 40 is cut along its film thickness direction.

[0141] This modified example, as shown in Figure 11, adds the opening 250 and wiring 252 of the third embodiment to the second embodiment. In this modified example, the diameter (crossover) D of the opening 250 of each light-emitting element 112 is ｂ , D ｇ , Dｒ The area (element aperture) L of each light-emitting element 112 is ｂ , L ｇ , L ｒ As the value decreases, that is, as the wavelength of light from each light-emitting element 112 increases, the value decreases.

[0142] More specifically, in this modified example, as shown in Figure 11, the diameter D of the aperture 250 of the first light-emitting element 112b with the shortest wavelength of light is ｂ The largest and second shortest wavelength of light produced is the diameter D of the aperture 250 of the light-emitting element 112g. ｇ The next largest is the diameter D of the aperture 250 of the third light-emitting element 112r, which has the longest wavelength of light. ｒ This is the smallest.

[0143] <<6. Fourth Embodiment>> Next, with reference to Figure 12, the detailed configuration of the pixel 20 according to the fourth embodiment of the present disclosure will be described. Figure 12 is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to this embodiment, and more specifically corresponds to a cross-section obtained when the substrate 40 is cut along its film thickness direction.

[0144] In the third embodiment described above, openings 250 are provided in the protective films 240, 242, and 244 to expose the upper surface of the cathode electrode 220, and the wiring 252 is extended to cover at least a portion of the inner wall of the opening 250, thereby electrically connecting the cathode electrodes 220 of adjacent light-emitting elements 112. On the other hand, in the fourth embodiment of this disclosure, as shown in Figure 12, protective films 270 are laminated on each cathode electrode 220. Furthermore, in this embodiment, the wiring 252 is extended to the side, bottom, and top surfaces of the protective film 270, thereby electrically connecting the wiring 252 to the cathode electrode 220. In this embodiment, the cathode electrodes 220 of adjacent light-emitting elements 112 are electrically connected to each other by the wiring 252 extending from the top surfaces of the protective films 240, 242, and 244, and from the top, bottom, and side surfaces of the protective film 270.

[0145] Furthermore, in this embodiment, it is preferable that the protective film 270 is a high refractive index material having a higher refractive index than the protective films 240, 242, and 244. Examples of high refractive index materials include titanium oxide (TiO2). ｘ ) and other oxide films, silicon nitride (SiN ｘ Nitride films such as silicon oxynitride (SiO ｘ N ｙ Examples include resin materials such as epoxy resins. In this embodiment, by embedding such a high refractive index material in the protective film 270, light can be efficiently extracted to the front and above of the light-emitting element 112.

[0146] In this embodiment, the pixel 20 is not limited to the form shown in Figure 12, but can be transformed into various forms.

[0147] <<7. Fifth Embodiment>> Next, the detailed configuration of the pixel 20 according to the fifth embodiment of the present disclosure will be described with reference to Figures 13A to 13D. Figures 13A to 13D are plan views illustrating an example of the configuration of the pixel 20 according to this embodiment, and more specifically, correspond to the plane when the substrate 40 is viewed from above. Note that in Figures 13A to 13D, the wiring 252 is not shown, and each light-emitting element 112 can be assigned any color. In the fifth embodiment of the present disclosure, variations in the planar shape of each light-emitting element 112 will be described.

[0148] In this embodiment, for example, as shown in Figure 13A, the planar shape of the light-emitting element 112 may be square (an example of a rectangular shape). Furthermore, the light-emitting elements 112 may be arranged in a square configuration (each light-emitting element 112 is placed at the vertices of a square), as shown in Figure 13A.

[0149] Furthermore, in this embodiment, for example, as shown in Figure 13B, the planar shape of the light-emitting element 112 may be rectangular (an example of a rectangular shape). In addition, the light-emitting elements 112 may be arranged in a stripe pattern, for example, as shown in Figure 13B.

[0150] Furthermore, in this embodiment, for example, as shown in Figure 13C, the planar shape of the light-emitting element 112 may be hexagonal (an example of a polygonal shape). Furthermore, the light-emitting elements 112 may be arranged in a delta array (each light-emitting element 112 is positioned at the vertices of a triangle), as shown in Figure 13C.

[0151] Furthermore, in this embodiment, for example, as shown in Figure 13D, the planar shape of the light-emitting element 112 may be circular. Furthermore, the light-emitting elements 112 may be arranged in a delta array (each light-emitting element 112 is positioned at the vertices of a triangle), as shown in Figure 13D.

[0152] In this embodiment, the pixels 20 are not limited to the shapes shown in Figures 13A to 13D, but can be transformed into various shapes. For example, the planar shape of the light-emitting element 112 may be a polygon (specifically, a triangle, square, pentagon, hexagon, etc.), a circle, or an ellipse. Furthermore, in this embodiment, for example, the size and shape of the light-emitting element 112 on the plane may differ depending on the color of light emitted by the light-emitting element 112. Also, in this embodiment, the arrangement of the light-emitting elements 112 is not limited to a square arrangement, stripe arrangement, delta arrangement, etc.

[0153] <<8. Sixth Embodiment>> <8.1 Background> Next, the background of the sixth embodiment of the present disclosure will be described with reference to Figure 14. Figure 14 is a cross-sectional view for explaining the background of this embodiment. In detail, Figure 14 is a cross-sectional view for explaining an example of the configuration of the pixel 20 according to the first embodiment described above, and in detail corresponds to a cross-section when the substrate 40 is cut along its film thickness direction.

[0154] In the embodiments of the present disclosure described above, including the first embodiment, the film thickness of each light-emitting layer 210b, 210g, and 210r was increased as the wavelength of light emitted by the corresponding light-emitting layers 210b, 210g, and 210r increased in order to realize a microcavity structure. More specifically, in these embodiments, as shown in Figure 14, for example, the distance between the anode electrodes (first reflective surfaces) 200b, 200g, and 200r, which function as reflective films, and the cathode electrodes (second reflective surfaces) 220b, 220g, and 220r, i.e., the optical distance L corresponding to the film thickness of each light-emitting layer 210b, 210g, and 210r, was set to satisfy the following formula (1) according to the emission peak wavelength λ of each light-emitting layer 210b, 210g, and 210r. However, in these embodiments, the integer m in formula (1) was the same integer for all light-emitting elements 112b, 112g, and 112r (for example, the integer m was set to 1). Therefore, in these embodiments, for example as shown in Figure 14, the film thickness of the light-emitting layer 210r of the light-emitting element 112r is the thickest, the film thickness of the light-emitting layer 210g of the light-emitting element 112g is the next thickest, and the film thickness of the light-emitting layer 210b of the light-emitting element 112b is the thinnest. As explained earlier, optical distance is the distance that light travels through the medium (in this case, the light-emitting layer 210) converted to the distance that light travels in a vacuum.

[0155] λ: Emission peak wavelength λ of each emission layer 210 Φ: Phase shift (radians) between the first and second reflecting surfaces m: integer

[0156] Furthermore, in order to more effectively improve color reproducibility and light extraction efficiency through the microcavity structure, it is preferable to set the integer m in formula (1) to 0 (0th order), and if it is difficult to set it to 0, it is preferable to set it to 1 (1st order).

[0157] As described above, in the embodiment shown in FIG. 14, the integer m in the formula (1) was set to the same integer (for example, 1) for all the light-emitting elements 112b, 112g, and 112r. In such a case, for the light-emitting element 112r, due to the material characteristics of the light-emitting layer 210r and the like, the light extraction efficiency (luminous efficiency) is likely to be lower than that of the other light-emitting elements 112b and 112g. Therefore, in order to make the light extraction efficiency (luminous efficiency) of the light-emitting element 112r equivalent to that of the other light-emitting elements 112b and 112g, the inventors conceived of setting the cavity structure of the light-emitting element 112r to satisfy the resonance condition of the zero order (that is, setting the integer m in the formula (1) to 0). Then, based on this concept, the inventors created the sixth embodiment of the present disclosure described below.

[0158] Specifically, in the embodiments described so far, the integer m in the formula (1) was set to the same integer (for example, 1) for all the light-emitting elements 112b, 112g, and 112r. Therefore, as shown in FIG. 14, in the embodiments described so far, the height H of the upper surface of the stacked structure of each light-emitting element 112b, 112g, and 112r with respect to the upper surface of the substrate 40 ｂ , H ｇ , H ｒ had a height corresponding to the color (wavelength) of the light corresponding to the light-emitting element 112. And in the embodiments described so far, the light-emitting elements 112b with a lower height corresponding to short-wavelength light were fabricated in order from the light-emitting element 112b with a lower height corresponding to short-wavelength light to the light-emitting elements 112g and 112r with a higher height corresponding to long-wavelength light.

[0159] On the other hand, in the sixth embodiment described below, since the integer m in the formula (1) is not set to the same integer for all the light-emitting elements 112b, 112g, and 112r, the height H of the upper surface of the stacked structure of each light-emitting element 112b, 112g, and 112r with respect to the upper surface of the substrate 40 ｂ , H ｇ , H ｒis not the height corresponding to the color (wavelength) of the light corresponding to the light-emitting element 112. For example, in the sixth embodiment, the cavity structure of the red light-emitting element 112r is set to satisfy the resonance condition of the zeroth order, and the cavity structures of the green light-emitting element 112g and the blue light-emitting element 112b are set to satisfy the resonance condition of the first order. By doing so, in the sixth embodiment, for example, the height H of the upper surface of the stacked structure of each of the light-emitting elements 112b, 112g, 112r with respect to the upper surface of the substrate 40 ｂ , H ｇ , H ｒ will gradually increase in the order of the light-emitting element 112r, the light-emitting element 112b, and the light-emitting element 112g. Further, in the sixth embodiment, according to this height, for example, the light-emitting elements 112r, 112b, and 112g with lower heights are sequentially fabricated from the light-emitting element 112r with a lower height to the light-emitting elements 112b and 112g with a higher height. Also in the sixth embodiment, by fabricating in this way, for example, the deposition of the light-emitting layers 210g and 210r of the light-emitting elements 112b and 112g to be fabricated next is less likely to be hindered by the previously fabricated light-emitting element 112r. As a result, in the sixth embodiment, the occurrence of curling 300 is suppressed, and for example, the light-emitting layers 210b and 210g of the light-emitting elements 112b and 112g formed second and later can be laminated so that their film thicknesses are uniform.

[0160] <8.2 Detailed Configuration> Next, referring to FIG. 15, the detailed configuration of the pixel 20 according to the sixth embodiment of the present disclosure will be described. FIG. 15 is a cross-sectional view for explaining an example of the configuration of the pixel 20 according to the present embodiment, and specifically corresponds to a cross-section when the substrate 40 is cut along its film thickness direction.

[0161] In this embodiment as well, as shown in Figure 15, each light-emitting element 112b, 112g, and 112r is separated from each other. Each light-emitting element 112 has a laminated structure consisting of an anode electrode (lower electrode) 200 provided on a substrate 40, a light-emitting layer 210 (specifically, light-emitting layers 210b, 210g, and 210r) laminated on the anode electrode 200, a cathode electrode (upper electrode) 220 (specifically, cathode electrodes 220b, 220g, and 220r) laminated on the light-emitting layer 210, and protective films 240, 242, and 244 laminated on the cathode electrode 220. Furthermore, the sides of the laminated structure of each light-emitting element 112 are covered by sidewall films consisting of protective films 240, 242, and 244.

[0162] Furthermore, in this embodiment, the cavity structure of the red light-emitting element 112r is configured to satisfy the zero-order resonance condition. Specifically, in the red light-emitting element 112r, the distance between the anode electrode (first reflective surface) 200r and the cathode electrode (second reflective surface) 220r, which functions as a reflective film, i.e., the optical distance L corresponding to the film thickness of the light-emitting layer 210r, is set such that, with an integer m of 0, the following formula (1) is satisfied.

[0163] Furthermore, in this embodiment, the cavity structures of the blue light-emitting element 112b and the green light-emitting element 112g are made to satisfy the first-order resonance conditions. Specifically, in the blue light-emitting element 112b and the green light-emitting element 112g, the optical distance L between the anode electrodes 200b, 200g, which function as reflective films, and the cathode electrodes 220b, 220g, that is, the optical distance L corresponding to the film thickness of the light-emitting layers 210b, 210g, is set such that the following formula (1) is satisfied, with an integer m of 1.

[0164] λ: Emission peak wavelength λ of each emission layer 210 Φ: Phase shift (radians) between the first and second reflecting surfaces m: integer

[0165] In other words, in this embodiment, as shown in Figure 15, for two of the three types of light-emitting elements 112r, 112b, and 112g, the longer the wavelength of the corresponding light, the thicker the light-emitting layers 210b and 210g become. More specifically, in this embodiment, for example, the light-emitting layer 210g of the light-emitting element 112g is the thickest, the light-emitting layer 210b of the light-emitting element 112b is the next thickest, and the light-emitting layer 210r of the light-emitting element 112r is the thinnest.

[0166] Furthermore, in this embodiment, as shown in Figure 15, the height H of the stacked structure of the light-emitting element 112r ｒ The lowest point is the height H of the stacked structure of the light-emitting element 112b. ｂ The next lowest is H. Furthermore, in this embodiment, the height H of the stacked structure of the light-emitting element 112g is ｇ This is the highest. In other words, in this embodiment, as shown in Figure 15, in the relationship between two of the three types of light-emitting elements 112r, 112b, and 112g (both primary), the longer the wavelength of the corresponding light, the higher the height H of the upper surface of the stacked structure of each light-emitting element 112b, 112g relative to the upper surface of the substrate 40. ｂ H ｇ The price is rising.

[0167] Furthermore, in this embodiment, as shown in Figure 15, the thickness of the sidewall film covering the sides of the stacked structure of each light-emitting element 112 differs for each light-emitting element 112. Specifically, in this embodiment, the sidewall film of the light-emitting element 112r is the thickest and consists of three layers: protective films 240, 242, and 244. In this embodiment, the sidewall film of the light-emitting element 112b is the next thickest and consists of two layers: protective films 242 and 244. Furthermore, in this embodiment, the sidewall film of the light-emitting element 112g is the thinnest and consists of one layer: protective film 244. In other words, in this embodiment, as shown in Figure 15, in the relationship between two of the three types of light-emitting elements 112r, 112b, and 112g (both primary), the longer the wavelength of the corresponding light, the fewer layers make up the sidewall film and the thinner the thickness of the sidewall film. In this context, the thickness of the sidewall film refers to the thickness of the portion of the film that makes up the sidewall film that covers the side surface of the laminated structure of the light-emitting element 112.

[0168] In other words, in this embodiment, the pixel 20 includes the light-emitting element with the shortest wavelength (first light-emitting element) 112b, the light-emitting element with the second longest wavelength (second light-emitting element) 112g, and the light-emitting element with the longest wavelength (third light-emitting element) 112r. In this embodiment, the film thickness of the light-emitting layer 210 increases in the order of light-emitting element 112r, light-emitting element 112b, and light-emitting element 112g, and the film thickness of the sidewall film decreases in the order of light-emitting element 112r, light-emitting element 112b, and light-emitting element 112g, and the height H of the upper surface of the laminated structure relative to the upper surface of the substrate 40. ｒ H ｂ H ｇ The light intensity increases in the order of light-emitting element 112r, light-emitting element 112b, and light-emitting element 112g.

[0169] In this embodiment, the pixel 20 is not limited to the form shown in Figure 15, but can be transformed into various forms.

[0170] <8.3 Modified Examples> Next, with reference to Figure 16, the detailed configuration of the pixel 20 according to a modified example of this embodiment will be described. Figure 16 is a cross-sectional view illustrating an example of the configuration of the pixel 20 according to a modified example of this embodiment, and in detail corresponds to a cross-section obtained when the substrate 40 is cut along its film thickness direction.

[0171] In this modified example, as shown in Figure 16, each light-emitting element 112b, 112g, and 112r is separated from each other. Each light-emitting element 112 has a laminated structure consisting of an anode electrode 200 provided on a substrate 40, a light-emitting layer 210 (specifically, light-emitting layers 210b, 210g, and 210r) laminated on the anode electrode 200, a cathode electrode 220 (specifically, cathode electrodes 220b, 220g, and 220r) laminated on the light-emitting layer 210, and protective films 240, 242, and 244 laminated on the cathode electrode 220. Furthermore, the sides of the laminated structure of each light-emitting element 112 are covered by sidewall films consisting of protective films 240, 242, and 244.

[0172] Furthermore, in this modified example, the cavity structures of the green light-emitting element 112g and the red light-emitting element 112r are made to satisfy the zero-order resonance condition. Specifically, in the green light-emitting element 112g and the red light-emitting element 112r, the distance between the anode electrodes (first reflective surfaces) 200g, 200r, which function as reflective films, and the cathode electrodes (second reflective surfaces) 220g, 220r, i.e., the optical distance L corresponding to the film thickness of the light-emitting layers 210g, 210r, is set such that the above formula (1) is satisfied, with an integer m of 0.

[0173] Furthermore, in this modified example, the cavity structure of the blue light-emitting element 112b is made to satisfy the first-order resonance condition. Specifically, in the blue light-emitting element 112b, the distance between the anode electrode 200b, which functions as a reflective film, and the cathode electrode 220b, i.e., the optical distance L corresponding to the film thickness of the light-emitting layer 210b, is set such that the above formula (1) is satisfied, with an integer m of 1.

[0174] In other words, in this modified example, as shown in Figure 16, in the relationship between two of the three types of light-emitting elements 112r, 112b, and 112g (both 0th order), the longer the wavelength of the corresponding light, the thicker the light-emitting layers 210g and 210r become. More specifically, in this modified example, for example, the light-emitting layer 210g of the light-emitting element 112g is the thinnest, the light-emitting layer 210r of the light-emitting element 112r is the next thinnest, and the light-emitting layer 210b of the light-emitting element 112b is the thickest.

[0175] Furthermore, in this modified example, as shown in Figure 16, the height H of the stacked structure of the light-emitting element 112g is as follows: ｇ The lowest point is the height H of the stacked structure of the light-emitting element 112r. ｒ The next lowest is H. Furthermore, in this modified example, the height H of the stacked structure of the light-emitting element 112b is ｂ This is the highest. In other words, in this modified example, as shown in Figure 16, in the relationship between two of the three types of light-emitting elements 112g and 112r (both 0th order), the longer the wavelength of the corresponding light, the higher the height H of the upper surface of the stacked structure of each light-emitting element 112g and 112r relative to the upper surface of the substrate 40. ｇ H ｒ The price is rising.

[0176] Furthermore, in this modified example, as shown in Figure 16, the thickness of the sidewall film covering the sides of the stacked structure of each light-emitting element 112 differs for each light-emitting element 112. Specifically, in this modified example, the sidewall film of the light-emitting element 112g is the thickest and consists of three layers: protective films 240, 242, and 244. Also in this modified example, the sidewall film of the light-emitting element 112r is the next thickest and consists of two layers: protective films 242 and 244. Moreover, in this modified example, the sidewall film of the light-emitting element 112b is the thinnest and consists of one layer: protective film 244. That is, in this modified example, as shown in Figure 16, in the relationship between two of the three types of light-emitting elements 112g and 112r (both 0th order), the longer the wavelength of the corresponding light, the fewer layers make up the sidewall film and the thinner the thickness of the sidewall film.

[0177] In other words, in this modified example, the pixel 20 includes the light-emitting element with the shortest wavelength (first light-emitting element) 112b, the light-emitting element with the second longest wavelength (second light-emitting element) 112g, and the light-emitting element with the longest wavelength (third light-emitting element) 112r. In this modified example, the film thickness of the light-emitting layer 210 increases in the order of light-emitting element 112g, light-emitting element 112r, and light-emitting element 112b, and the film thickness of the sidewall film decreases in the order of light-emitting element 112g, light-emitting element 112r, and light-emitting element 112b, and the height H of the upper surface of the laminated structure relative to the upper surface of the substrate 40. ｒ H ｂ H ｇ The light intensity increases in the order of light-emitting element 112g, light-emitting element 112r, and light-emitting element 112b.

[0178] As described above, in this embodiment and its modified form, at least two of the multiple light-emitting elements 112 are manufactured in order from the shortest light-emitting elements 112 corresponding to short wavelengths of light to the tallest light-emitting elements 112 corresponding to long wavelengths of light. In this embodiment and its modified form, by manufacturing in this way, the deposition of the light-emitting layer 210 of the next light-emitting element 112 is less likely to be hindered by the previously manufactured light-emitting elements 112. Therefore, in this embodiment and its modified form, the material for the light-emitting layer 210 is more easily deposited on the anode electrode 200 of the second and subsequent light-emitting elements 112. As a result, in this embodiment and its modified form, vignetting 300 on the light-emitting layer 210 is suppressed, and the light-emitting layers 210 of the second and subsequent light-emitting elements 112 can be laminated so that their film thickness is uniform.

[0179] Furthermore, in this embodiment and its modified form, at least one of the multiple light-emitting elements 112 has a cavity structure with a zero-order resonance condition, which allows the height of the stacked structure of the light-emitting elements 112 to be reduced. As a result, according to this embodiment and its modified form, an increase in the manufacturing time and manufacturing cost of the display device 10 can be suppressed. In addition, in this embodiment and its modified form, since the height of the stacked structure of the light-emitting elements 112 can be reduced, the on-chip lens 266 provided above the light-emitting elements 112 can be provided closer to the light-emitting layer 210, thus shortening the distance between the light-emitting layer 210 and the on-chip lens 266. This makes it easier for the on-chip lens 266 to capture light from the light-emitting layer 210 without leakage, and suppresses light leakage to adjacent light-emitting elements 112.

[0180] In this embodiment, for example, a reflective film (not shown) that functions as the first reflective surface may be provided below the anode electrode 200. That is, in this embodiment, the first and second reflective surfaces are not limited to the anode electrode 200 and the cathode electrode 220. In such a case, the optical distance L shown in formula (1) above is the distance between the layer that functions as the first reflective surface and the layer that functions as the second reflective surface.

[0181] <<9. Seventh Embodiment>> <9.1 Background> Next, the background of the seventh embodiment of the present disclosure will be described with reference to Figure 17. Figure 17 is a plan view for explaining the background of this embodiment. In detail, the upper left of Figure 17 shows the planar configuration of the pixel 20 according to the fifth embodiment described above, and the upper right shows an example of the planar configuration of the pixel 20 according to the seventh embodiment. Furthermore, the lower left of Figure 17 schematically shows a cross-section in one step of the manufacturing method of the pixel 20 according to the fifth embodiment described above, and the lower right shows a cross-section in one step of the manufacturing method of the pixel 20 according to the seventh embodiment described above.

[0182] In the planar configuration according to the fifth embodiment shown in the upper left of Figure 17, the planar shape of each light-emitting element 112 (specifically, three types of light-emitting elements 112b, 112g, and 112r) is circular and arranged in a delta configuration (each light-emitting element 112 is positioned at the vertices of a triangle). In this planar configuration, in order to suppress interference with the deposition of the light-emitting layer 210 due to vignetting 300 during the fabrication of each light-emitting element 112, the light-emitting layers 210 of each light-emitting element 112 (specifically, three types of light-emitting layers 210b, 210g, and 210r) are arranged with a predetermined interval S1.

[0183] Incidentally, in order to further improve the brightness of the display area of ​​the display device 10, it is preferable to increase the light-emitting area (light-emitting area / element aperture) of the light-emitting layer 210 of each light-emitting element 112. However, in the planar configuration shown in the upper left of Figure 17, there was a limit to how large the element aperture of the light-emitting element 112 could be made in order to secure a gap S1 to suppress the deposition of the light-emitting layer 210 being hindered by vignetting 300.

[0184] Therefore, in this situation, the inventors have uniquely discovered that when the light-emitting layer 210 is formed by vapor deposition, vignetting 300 exhibits anisotropy, and have come to create the seventh embodiment of the present disclosure described below. In detail, depending on the vapor deposition method, the vapor deposition vignetting 300 that occurs in the film formation process of the light-emitting layer 210 exhibits anisotropy, meaning that it is more likely to occur in a specific direction and less likely to occur in other directions. For example, in the planar configuration shown in the upper left of Figure 17, vignetting 300 is more likely to occur in the X-axis direction (row direction), and less likely to occur in the Y-axis direction (column direction). Therefore, the inventors considered that in the direction where vignetting 300 is less likely to occur, even if the distance between light-emitting elements 112 is narrowed compared to the direction where vignetting 300 is more likely to occur, it may be possible to avoid the occurrence of vignetting 300 and to make the film thickness of the light-emitting layer 210 of the second and subsequent light-emitting elements 112 uniform. Based on this idea, the inventors conceived the idea of ​​extending the light-emitting elements 112 to enlarge the element aperture, since it is possible to narrow the distance S2 between the light-emitting elements 112 in a direction in which vignetting 300 is less likely to occur, and thus created the seventh embodiment of this disclosure.

[0185] In detail, in the seventh embodiment, for example, as shown in the upper right of Figure 17, in the Y-axis direction (an example of the first direction) where vignetting 300 is less likely to occur, the distance S2 between the light-emitting elements 112 can be narrowed. Therefore, the light-emitting elements 112b and 112g (specifically, the light-emitting layers 210b and 210g) are stretched to enlarge the element apertures of the light-emitting elements 112b and 112g. That is, in this embodiment, as shown in the lower right of Figure 17, the spacing S2 between the light-emitting layers 210 of each light-emitting element 112 is narrower in the Y-axis direction compared to the example shown in the lower left of Figure 17. Furthermore, in this embodiment, in the X-axis direction (an example of the second direction) where vignetting 300 is likely to occur, the light-emitting elements 112b, 112g, and 112r (specifically, the light-emitting layers 210b, 210g, and 210r) are slightly stretched while maintaining the distance between the light-emitting elements 112 at a predetermined interval, thereby increasing the element apertures of the light-emitting elements 112b, 112g, and 112r. The details of the seventh embodiment of this disclosure, created by the inventors, will now be described in order.

[0186] In the seventh embodiment described below, the directions in which vignetting 300 is likely to occur and the directions in which vignetting 300 is unlikely to occur are not limited to the X-axis and Y-axis directions as described above. Also, in this embodiment, the method for forming the light-emitting layer 210 is not limited to vapor deposition, but may be any other method as long as it is anisotropic.

[0187] <9.2 Detailed Configuration> Next, the detailed configuration of the pixel 20 according to the seventh embodiment of the present disclosure will be described with reference to Figure 18. Figure 18 is a plan view illustrating an example of the configuration of the pixel 20 according to this embodiment. Specifically, the left side of Figure 18 shows a plan view of the pixel 20 corresponding to the plane when the substrate 40 is viewed from above, and the right side of Figure 18 shows the plan configuration of one light-emitting element 112. This embodiment is a further modification of the fifth embodiment shown in Figure 13D.

[0188] In this embodiment, as shown on the left side of Figure 18, within a pixel (pixel unit) 20, three light-emitting elements (an example of a first light-emitting element) 112b and three light-emitting elements (an example of a second light-emitting element) 112g are arranged alternately around one light-emitting element (an example of a third light-emitting element) 112r. Furthermore, in this embodiment, each of the light-emitting elements 112b and 112g is arranged so as to be separated from the light-emitting element 112r by a predetermined distance S3. In this embodiment, it is preferable that the predetermined distance S3 be as narrow as possible within the range that can suppress the occurrence of vignetting 300 and is within the range that is permissible for manufacturing. Also, within the pixel 20, the multiple light-emitting elements 112b and 112g are arranged in a line-symmetric relationship with respect to the X-axis (axis along the row direction) passing through the center of the pixel 20. Furthermore, if the type of light-emitting element 112 is not distinguished, in this embodiment, the multiple light-emitting elements 112 are arranged in a delta array (each light-emitting element 112 is arranged at the vertices of a triangle). In this embodiment, the plurality of pixels 20 are arranged in a matrix within the display area (pixel array portion) of the display device 10, that is, along the X and Y axes.

[0189] In this embodiment, as shown on the left side of Figure 18, for example, in the Y-axis direction where vignetting 300 is less likely to occur, the light-emitting elements 112b and 112g (specifically, the light-emitting layers 210b and 210g) are stretched to enlarge the element apertures of the light-emitting elements 112b and 112g. More specifically, the length of the planar shape of the light-emitting elements 112b and 112g along the Y-axis (column direction) is different from the length along the X-axis (row direction). More specifically, the length of the planar shape of the light-emitting elements 112b and 112g along the Y-axis is longer than the length along the X-axis. Furthermore, in this embodiment, in the X-axis direction where vignetting 300 is more likely to occur, the distance between the light-emitting elements 112 is maintained at a predetermined interval, and the light-emitting elements 112b and 112g (specifically, the light-emitting layers 210b and 210g) are partially stretched slightly to enlarge the element apertures of the light-emitting elements 112b and 112g. In other words, the planar shapes of the light-emitting elements 112b and 112g are symmetrical with respect to the axis 412 along the Y-axis (axis along the column direction) passing through the center 410 of the light-emitting elements 112b and 112g, as shown on the right side of Figure 18, but are not symmetrical with respect to the axis 414 along the X-axis (axis along the row direction) passing through the center 410 of the light-emitting elements 112b and 112g. More specifically, the shapes of the light-emitting elements 112b and 112g are teardrop-shaped, or in other words, based on an isosceles triangle, but with the vertices of the isosceles triangle being curved, and the base angles of the isosceles triangle being beveled at approximately 45 degrees (C-chamfer).

[0190] In addition, in this embodiment, as shown on the left side of Figure 18, the light-emitting element 112r (specifically, the light-emitting layer 210r) is slightly stretched in the X-axis direction to enlarge the element aperture of the light-emitting element 112r. Specifically, the length of the planar shape of the light-emitting element 112r along the Y-axis (column direction) is different from the length along the X-axis (row direction). More specifically, the length of the planar shape of the light-emitting element 112r along the Y-axis is shorter than the length along the X-axis. Furthermore, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center 420 of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center 420 of the light-emitting element 112r. More specifically, in this embodiment, the planar shape of the light-emitting element 112r is basically a rectangle, but the four corners of the rectangle are beveled at approximately 45 degrees (C-chamfer).

[0191] Furthermore, in this embodiment, as shown on the left side of Figure 18, the length of the side where the light-emitting element 112b and the light-emitting element 112g face each other is longer than the side where the light-emitting element 112r and the light-emitting element 112g face each other, and the side where the light-emitting element 112r and the light-emitting element 112b face each other.

[0192] In this embodiment, the pixel 20 is not limited to the form shown in Figure 18, but can be transformed into various forms.

[0193] <9.3 Modified Examples> Next, the detailed configuration of the pixel 20 according to a modified example of this embodiment will be described with reference to Figures 19 to 22. Figures 19 to 22 are plan views illustrating an example of the configuration of the pixel 20 according to a modified example of this embodiment, and in detail correspond to a plane view of the substrate 40 when viewed from above.

[0194] As shown on the left side of Figure 19, in this modified example, the center of the light-emitting element 112r may be slightly offset from the center 420 of the pixel 20. Also, in this modified example, as shown on the right side of Figure 19, the light-emitting element 112r may be smaller than the light-emitting elements 112b and 112g.

[0195] Furthermore, as shown on the left side of Figure 20, in this modified example, the planar shape of the light-emitting element 112r may be elliptical. More specifically, in this modified example, the length of the planar shape of the light-emitting element 112r along the Y-axis is shorter than the length along the X-axis. Also, in this modified example, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center 420 of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center 420 of the light-emitting element 112r.

[0196] Furthermore, in this modified example, as shown on the right side of Figure 20, the planar shape of the light-emitting element 112r is similar to a rectangle, and the four corners of the rectangle may protrude outward in a triangular shape. Also in this modified example, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center 420 of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center 420 of the light-emitting element 112r.

[0197] Furthermore, as shown on the left side of Figure 21, in this modified example, the planar shapes of the light-emitting elements 112b, 112g, and 112r may be elliptical. More specifically, in this modified example, the length of the planar shapes of the light-emitting elements 112b and 112g along the Y-axis is longer than the length along the X-axis. Also, the planar shapes of the light-emitting elements 112b and 112g have line symmetry with respect to the axis along the Y-axis passing through the center of the light-emitting elements 112b and 112g, and line symmetry with respect to the axis along the X-axis passing through the center 410 of the light-emitting elements 112b and 112g. Moreover, in this modified example, the length of the planar shape of the light-emitting element 112r along the Y-axis is shorter than the length along the X-axis. Also, in this modified example, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center of the light-emitting element 112r.

[0198] Furthermore, as shown in the center of Figure 21, in this modified example, the planar shapes of the light-emitting elements 112b and 112g may be isosceles triangles. More specifically, in this modified example, the length of the planar shapes of the light-emitting elements 112b and 112g along the Y-axis is longer than the length along the X-axis. Also, the planar shapes of the light-emitting elements 112b and 112g have line symmetry with respect to the axis along the Y-axis passing through the center of the light-emitting elements 112b and 112g, but do not have line symmetry with respect to the axis along the X-axis passing through the center 410 of the light-emitting elements 112b and 112g. Moreover, in this modified example, the planar shape of the light-emitting element 112r may be a rectangle. In this modified example, the length of the planar shape of the light-emitting element 112r along the Y-axis is shorter than the length along the X-axis. Also, in this modified example, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center of the light-emitting element 112r.

[0199] Furthermore, as shown on the right side of Figure 21, in this modified example, the planar shapes of the light-emitting elements 112b and 112g may be trapezoidal. More specifically, in this modified example, the length of the planar shapes of the light-emitting elements 112b and 112g along the Y-axis is longer than the length along the X-axis. Also, the planar shapes of the light-emitting elements 112b and 112g have line symmetry with respect to the axis along the Y-axis passing through the center of the light-emitting elements 112b and 112g, but do not have line symmetry with respect to the axis along the X-axis passing through the center of the light-emitting elements 112b and 112g. Furthermore, in this modified example, the planar shape of the light-emitting element 112r may be cross-shaped. Also, in this modified example, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center of the light-emitting element 112r.

[0200] Furthermore, as shown on the left side of Figure 22, in this modified example, the planar shapes of the light-emitting elements 112b and 112g may be pentagonal. Also, the planar shapes of the light-emitting elements 112b and 112g have line symmetry with respect to the axis along the Y-axis passing through the center of the light-emitting elements 112b and 112g, but do not have line symmetry with respect to the axis 414 along the X-axis passing through the center of the light-emitting elements 112b and 112g. Moreover, in this modified example, the planar shape of the light-emitting element 112r may be hexagonal. In this modified example, the length of the planar shape of the light-emitting element 112r along the Y-axis is longer than the length along the X-axis. Also, in this modified example, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center of the light-emitting element 112r.

[0201] Furthermore, as shown on the right side of Figure 22, in this modified example, the planar shapes of the light-emitting elements 112b, 112g, and 112r may be hexagonal. Also, the planar shapes of the light-emitting elements 112b and 112g have line symmetry with respect to the axis along the Y-axis passing through the center of the light-emitting elements 112b and 112g, and line symmetry with respect to the axis 414 along the X-axis passing through the center 410 of the light-emitting elements 112b and 112g. Moreover, in this modified example, the length of the planar shape of the light-emitting element 112r along the Y-axis is longer than the length along the X-axis. Also, in this modified example, the planar shape of the light-emitting element 112r has line symmetry with respect to the Y-axis passing through the center of the light-emitting element 112r, and line symmetry with respect to the X-axis passing through the center of the light-emitting element 112r.

[0202] In this embodiment and its modified form, the planar shape of the light-emitting element 112r may be a square, a circle, or the like, in addition to those described above.

[0203] As described above, in this embodiment and its modified form, in the Y-axis direction (an example of the first direction) where vignetting 300 is less likely to occur, the distance S2 between the light-emitting elements 112 can be narrowed. Therefore, the light-emitting elements 112 (specifically, the light-emitting layer 210) are lengthened to enlarge the element aperture of the light-emitting elements 112b. Accordingly, in this embodiment and its modified form, the brightness of the display area of ​​the display device 10 can be further improved.

[0204] In this embodiment, the color of the light emitted from each light-emitting element 112 is not limited to those described above. Furthermore, this embodiment is not limited to being a further modification of the fifth embodiment shown in Figure 13D, and can be implemented independently without being combined with other embodiments.

[0205] <<10. Summary>> As described above, in each embodiment of the present disclosure, at least two of the plurality of light-emitting elements 112 are manufactured in order from the short-profile light-emitting elements 112 corresponding to short wavelength light to the tall-profile light-emitting elements 112 corresponding to long wavelength light. In each embodiment of the present disclosure, by manufacturing in this manner, the deposition of the light-emitting layer 210 of the next light-emitting element 112 is less likely to be hindered by the previously manufactured light-emitting elements 112. Therefore, in each embodiment of the present disclosure, the material for the light-emitting layer 210 is more easily deposited on the anode electrode 200 of the second and subsequent light-emitting elements 112. As a result, in each embodiment of the present disclosure, vignetting 300 on the light-emitting layer 210 is suppressed, and the light-emitting layers 210 of the second and subsequent light-emitting elements 112 can be laminated so that their film thickness is uniform.

[0206] Accordingly, according to each embodiment of the present disclosure, it is possible to suppress the decrease in reliability of the light-emitting element 112 caused by the local thinning of the light-emitting layer 210 and to avoid shortening the product life of the display device 10.

[0207] Furthermore, in each embodiment of this disclosure, the positions of each light-emitting element 112b, 112g, and 112r are not limited to the above description or figures, and can be interchanged.

[0208] Furthermore, each embodiment of this disclosure is not limited to the form shown in the figures, but can be modified in various ways and can also be combined with one another.

[0209] Furthermore, each embodiment of the present disclosure can be manufactured by a method similar to the manufacturing method of the pixel 20 (display device 10) according to the first embodiment of the present disclosure.

[0210] Furthermore, the display device 10 according to the embodiment of this disclosure can be applied to, for example, display devices for VR (Virtual Reality), MR (Mixed Reality), or AR (Augmented Reality), display devices for smartphones, television equipment, electronic viewfinders (EVF), or small projectors. The display device 10 can also be applied to various lighting devices (light-emitting devices).

[0211] <<11. Modifications>> <11.1 Modification 1> Next, as a modification of the embodiment of the present disclosure, a modification concerning the relationship between the normal LN passing through the center of the light-emitting part of the subpixel 100 (more specifically, the light-emitting layer 210 of a plurality of light-emitting elements 112 included in one subpixel 100), the normal LN' passing through the center of the lens member (more specifically, the on-chip lens 266), and the normal LN" passing through the center of the wavelength selection part (more specifically, the color filter 262) will be described with reference to Figures 23A to 23G. Figures 23A to 23G are conceptual diagrams for explaining the relationship between the normal LN passing through the center of the light-emitting part, the normal LN' passing through the center of the lens member, and the normal LN" passing through the center of the wavelength selection part. In the following description, the center of the subpixel 100 will be referred to as the center of the light-emitting part.

[0212] In embodiments of this disclosure, the size of the wavelength selection area may be appropriately changed in response to the light emitted by the subpixel 100. Furthermore, if a light absorption layer (black matrix layer) is provided between the wavelength selection areas of adjacent subpixels 100, the size of the light absorption layer (black matrix layer) may be appropriately changed in response to the light emitted by the subpixel 100. In addition, the size of the wavelength selection area may be determined by the distance (offset amount) d between the normal vector passing through the center of the subpixel 100 and the normal vector passing through the center of the color filter. ０ Depending on the circumstances, it may be changed as appropriate. The planar shape of the wavelength selection section may be the same as, similar to, or different from, the planar shape of the lens component (e.g., on-chip lens).

[0213] For example, as shown in Figure 23A, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength selection part, and the normal vector LN' passing through the center of the lens member may be made to coincide. In other words, the distance (offset amount) D between the normal vector passing through the center of the light-emitting part and the normal vector passing through the center of the lens member. ０ The distance (offset amount) d between the normal vector passing through the center of the light-emitting part and the normal vector passing through the center of the wavelength-selecting part. ０ This is equivalent to 0 (zero).

[0214] Furthermore, for example, as shown in Figure 23B, the normal vector LN passing through the center of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part coincide, but the normal vector LN passing through the center of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part do not have to coincide with the normal vector LN' passing through the center of the lens member. In other words, D ０ ≠d ０ It may also be 0.

[0215] Furthermore, for example, as shown in Figure 23C, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, but the normal vector LN'' passing through the center of the wavelength-selecting part and the normal vector LN' passing through the center of the lens member may coincide. In other words, D ０ = d ０ It can also be 0.

[0216] Furthermore, as shown in Figure 23D, for example, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, and the normal vector LN' passing through the center of the lens member does not coincide with the normal vector LN passing through the center of the surface of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part. Here, it is preferable that the center of the wavelength-selecting part (shown as a black circle in Figure 23D) is located on a straight line LL connecting the center of the surface of the light-emitting part and the center of the lens member (shown as a black circle in Figure 23D). Specifically, the distance from the center of the surface of the light-emitting part in the thickness direction to the center of the wavelength-selecting part is LL. １ The distance from the center of the wavelength selection area in the thickness direction to the center of the lens material is LL ２ In that case, D ０ >d０ > 0, and considering manufacturing variations, d ０ : D ０ =LL １ : (LL １ +LL ２ It is preferable that the following conditions be met.

[0217] Furthermore, the stacking relationship between the wavelength selection unit and the lens member may be reversed. In such a case, for example, as shown in Figure 23E, the normal vector LN passing through the center of the light-emitting unit, the normal vector LN'' passing through the center of the wavelength selection unit, and the normal vector LN' passing through the center of the lens member may be made to coincide. In other words, D ０ = d ０ It may also be 0.

[0218] Furthermore, for example, as shown in Figure 23F, the normal vector LN passing through the center of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, but the normal vector LN'' passing through the center of the wavelength-selecting part and the normal vector LN' passing through the center of the lens member may coincide. In other words, D ０ = d ０ It can also be 0.

[0219] Furthermore, as shown in the conceptual diagram Figure 23G, the normal vector LN passing through the center of the surface of the light-emitting part, the normal vector LN'' passing through the center of the wavelength-selecting part, and the normal vector LN' passing through the center of the lens member do not coincide, and the normal vector LN' passing through the center of the lens member does not coincide with the normal vector LN passing through the center of the surface of the light-emitting part and the normal vector LN'' passing through the center of the wavelength-selecting part. Here, it is preferable that the center of the wavelength-selecting part is located on the straight line LL connecting the center of the surface of the light-emitting part and the center of the lens member. Specifically, the distance from the center of the surface of the light-emitting part in the thickness direction to the center of the wavelength-selecting part (shown as a black circle in Figure 23G) is LL. １ The distance from the center of the wavelength selection area in the thickness direction to the center of the lens member (shown as a black circle in Figure 23G) is LL ２ When that happens, d ０ >D ０ > 0, and considering manufacturing variations, D ０ :d ０ =LL ２ : (LL １+LL ２ It is preferable that the following conditions be met.

[0220] Furthermore, in this modified example 1, the amount of positional deviation between the normal LN passing through the center of the surface of the light-emitting part, the normal LN'' passing through the center of the wavelength selection part, and the normal LN' passing through the center of the lens member may differ depending on the position of the subpixel 100 (light-emitting element 112) in the display area (pixel array part) of the display device 10.

[0221] <11.2 Modification 2> The subpixel 1100 (specifically, the light-emitting element 112) used in the display device according to the embodiment of the present disclosure described above may be configured to have a resonator structure that resonates the light generated in the light-emitting section (specifically, the light-emitting layer 210). The resonator structure will be described below with reference to Figures 24 to 30. Figure 24 is a schematic cross-sectional view illustrating a first example of the resonator structure, Figure 25 is a schematic cross-sectional view illustrating a second example of the resonator structure, and Figure 26 is a schematic cross-sectional view illustrating a third example of the resonator structure. Furthermore, Figure 27 is a schematic cross-sectional view illustrating a fourth example of the resonator structure, and Figure 28 is a schematic cross-sectional view illustrating a fifth example of the resonator structure. Furthermore, Figure 29 is a schematic cross-sectional view illustrating a sixth example of the resonator structure, and Figure 30 is a schematic cross-sectional view illustrating a seventh example of the resonator structure. In these diagrams, the letters attached to each symbol indicate the corresponding color of light; specifically, "B" represents blue, "G" represents green, and "R" represents red.

[0222] (Resonator Structure: First Example) Figure 24 is a schematic cross-sectional view illustrating the first example of a resonator structure. In the first example, the first electrode (e.g., anode electrode 200) 1202 is formed with a common film thickness in each subpixel 1100. The same applies to the second electrode (e.g., cathode electrode 220) 1206.

[0223] As shown in Figure 24, a reflector 1401 is positioned below the first electrode 1202 of the subpixel 1100, with an optical adjustment layer 1402 in between. A resonator structure is formed between the reflector 1401 and the second electrode 1206, causing the light generated by the organic layer (specifically, the light-emitting layer 210) 1204 to resonate.

[0224] The reflector 1401 is formed with a common film thickness for each subpixel 1100. The film thickness of the optical adjustment layer 1402 differs depending on the color that the subpixel 1100 is to display. By having optical adjustment layers 1402R, 1402G, and 1402B with different film thicknesses, it is possible to set the optical distance that produces the optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0225] In the example shown in Figure 24, the upper surfaces of the reflectors 1401 for subpixels 1100R, 1100G, and 1100B are aligned. As described above, the thickness of the optical adjustment layer 1402 differs depending on the color that the subpixel 1100 should display, so the position of the upper surface of the second electrode 1206 differs depending on the type of subpixel 1100R, 1100G, and 1100B.

[0226] The reflector 1401 can be formed using, for example, a metal such as aluminum (Al), silver (Ag), or copper (Cu), or an alloy mainly composed of these metals.

[0227] The optical adjustment layer 1402 can be constructed using inorganic insulating materials such as silicon nitride (SiNx), silicon oxide (SiOx), or silicon oxynitride (SiOxNy), or organic resin materials such as acrylic resin or polyimide resin. The optical adjustment layer 1402 may be a single layer or a laminated film of multiple materials. Furthermore, the number of layers may vary depending on the type of subpixel 1100.

[0228] The first electrode 1202 can be formed using a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO).

[0229] The second electrode 1206 preferably functions as a semi-transparent reflective film. The second electrode 1206 can be formed using magnesium (Mg), silver (Ag), or a magnesium-silver alloy (MgAg) mainly composed of these, or an alloy containing alkali metals or alkaline earth metals.

[0230] (Resonator structure: Second example) Figure 25 is a schematic cross-sectional view illustrating a second example of the resonator structure. In this second example as well, the first electrode 1202 and the second electrode 1206 are formed with a common film thickness in each subpixel 1100.

[0231] In the second example as well, a reflector 1401 is placed beneath the first electrode 1202 of the subpixel 1100, with an optical adjustment layer 1402 in between. A resonator structure is formed between the reflector 1401 and the second electrode 1206 to resonate the light generated by the organic layer 1204. Similar to the first example, the reflector 1401 is formed with a common film thickness for each subpixel 1100, while the film thickness of the optical adjustment layer 1402 differs according to the color that the subpixel 1100 should display.

[0232] In the first example shown in Figure 24, the upper surfaces of the reflectors 1401 for subpixels 1100R, 1100G, and 1100B were aligned, while the position of the upper surface of the second electrode 1206 differed depending on the type of subpixel 1100R, 1100G, and 1100B.

[0233] In contrast, in the second example shown in Figure 25, the upper surface of the second electrode 1206 is arranged to align with the subpixels 1100R, 1100G, and 1100B. In order to align the upper surfaces of the second electrode 1206, the upper surface of the reflector 1401 is arranged differently for the subpixels 1100R, 1100G, and 1100B, depending on the type of subpixel. As a result, the lower surface of the reflector 1401 has a stepped shape depending on the type of subpixel 1100R, 1100G, and 1100B.

[0234] The materials and other components constituting the reflector 1401, the optical adjustment layer 1402, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0235] (Resonator structure: Third example) Figure 26 is a schematic cross-sectional view illustrating the third example of the resonator structure. In the third example as well, the first electrode 1202 and the second electrode 1206 are formed with a common film thickness in each subpixel 1100.

[0236] In the third example, the reflector 1401 is positioned below the first electrode 1202 of the subpixel 1100, with the optical adjustment layer 1402 in between. A resonator structure is formed between the reflector 1401 and the second electrode 1206 to resonate the light generated by the organic layer 1204. Similar to the first and second examples, the thickness of the optical adjustment layer 1402 varies depending on the color that the subpixel 1100 should display. And, similar to the second example, the upper surface of the second electrode 1206 is positioned so that it aligns with the subpixels 1100R, 1100G, and 1100B.

[0237] In the second example shown in Figure 25, the lower surface of the reflector 1401 had a stepped shape corresponding to the type of sub-pixel 1100R, 1100G, and 1100B in order to align the upper surface of the second electrode 1206.

[0238] In contrast, in the third example shown in Figure 26, the film thickness of the reflector 1401 is set to differ depending on the type of sub-pixel 1100R, 1100G, and 1100B. More specifically, the film thickness is set so that the lower surfaces of the reflectors 1401R, 1401G, and 1401B are aligned.

[0239] The materials constituting the reflector 1401, the optical adjustment layer 1402, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0240] (Resonator structure: 4th example) Figure 27 is a schematic cross-sectional view illustrating the 4th example of a resonator structure.

[0241] In the first example shown in Figure 24, the first electrode 1202 and the second electrode 1206 of the subpixel 1100 are formed with a common film thickness. A reflector 1401 is placed below the first electrode 1202 of the subpixel 1100, with an optical adjustment layer 1402 in between.

[0242] In contrast, in the fourth example shown in Figure 27, the optical adjustment layer 1402 is omitted, and the film thickness of the first electrode 1202 is set to differ depending on the type of subpixel 1100R, 1100G, and 1100B.

[0243] The reflector 1401 is formed with a common film thickness for each subpixel 1100. The film thickness of the first electrode 1202 differs depending on the color that the subpixel 1100 is to display. By having the first electrodes 1202R, 1202G, and 1202B have different film thicknesses, it is possible to set the optical distance that produces the optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0244] The materials constituting the reflector 1401, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0245] (Resonator structure: Fifth example) Figure 28 is a schematic cross-sectional view illustrating the fifth example of a resonator structure.

[0246] In the first example shown in Figure 24, the first electrode 1202 and the second electrode 1206 are formed with a common film thickness in each subpixel 1100. A reflector 1401 is placed below the first electrode 1202 of the subpixel 1100, with an optical adjustment layer 1402 in between.

[0247] In contrast, in the fifth example shown in Figure 28, the optical adjustment layer 1402 was omitted, and instead, an oxide film 1404 was formed on the surface of the reflector 1401. The thickness of the oxide film 1404 was set to differ depending on the type of subpixel 1100R, 1100G, and 1100B.

[0248] The thickness of the oxide film 1404 varies depending on the color that the subpixel 1100 is to display. By having oxide films 1404R, 1404G, and 1404B with different thicknesses, it is possible to set the optical distance that produces the optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0249] The oxide film 1404 is a film obtained by oxidizing the surface of the reflector 1401, and is composed of, for example, aluminum oxide, tantalum oxide, titanium oxide, magnesium oxide, zirconium oxide, etc. The oxide film 1404 functions as an insulating film for adjusting the optical path length (optical distance) between the reflector 1401 and the second electrode 1206.

[0250] The oxide film 1404, which has a different thickness depending on the type of subpixel 1100R, 1100G, and 1100B, can be formed, for example, as follows.

[0251] First, the container is filled with electrolyte, and the substrate on which the reflector 1401 is formed is immersed in the electrolyte. Then, electrodes are positioned opposite the reflector 1401.

[0252] Then, a positive voltage is applied to the reflector 1401 with the electrode as the reference, and the reflector 1401 is anodized. The thickness of the oxide film formed by anodization is proportional to the voltage value applied to the electrode. Therefore, anodization is performed on each of the reflectors 1401R, 1401G, and 1401B with a voltage corresponding to the type of sub-pixel 1100R, 1100G, and 1100B applied. This makes it possible to form oxide films 1404 of different thicknesses all at once.

[0253] The materials constituting the reflector 1401, the first electrode 1202, and the second electrode 1206 are the same as those described in the first example, so their explanation will be omitted.

[0254] (Resonator Structure: Sixth Example) Figure 29 is a schematic cross-sectional view illustrating the sixth example of a resonator structure. In the sixth example, the subpixel 1100 is constructed by stacking a first electrode 1202, an organic layer 1204, and a second electrode 1206. However, in the sixth example, the first electrode 1202 is formed to serve both as an electrode and a reflector. The first electrode (and reflector) 1202 is made of a material having optical constants selected according to the type of subpixel 1100R, 1100G, and 1100B. By different phase shifts caused by the first electrode (and reflector) 1202, it is possible to set an optical distance that produces optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0255] The first electrode (and reflector) 1202 can be made from a single metal such as aluminum (Al), silver (Ag), gold (Au), or copper (Cu), or from an alloy mainly composed of these metals. For example, the first electrode (and reflector) 1202R of the subpixel 1100R can be made of copper (Cu), and the first electrode (and reflector) 1202G of the subpixel 1100G and the first electrode (and reflector) 1202B of the subpixel 1100B can be made of aluminum.

[0256] The materials and other components constituting the second electrode 1206 are the same as those described in the first example, so we will omit further explanation.

[0257] (Resonator Structure: Seventh Example) Figure 30 is a schematic cross-sectional view illustrating the seventh example of the resonator structure. The seventh example basically applies the sixth example to subpixels 1100R and 1100G, and the first example to subpixel 1100B. In this configuration as well, it is possible to set the optical distance that produces optimal resonance for the wavelength of light corresponding to the color to be displayed.

[0258] The first electrodes (which also serve as reflectors) 1202R and 1202G used in the sub-pixels 1100R and 1100G can be made from elemental metals such as aluminum (Al), silver (Ag), gold (Au), and copper (Cu), or alloys in which these metals are the main components.

[0259] The materials constituting the reflector 1401B, optical adjustment layer 1402B, and first electrode 1202B used in the subpixel 1100B are the same as those described in the first example, so their explanation will be omitted.

[0260] <<12. Application Examples>> For example, the technology relating to this disclosure may be applied to the display units of various electronic devices. Therefore, examples of electronic devices to which this technology can be applied will be described below.

[0261] (Specific Example 1) Figure 31A is a front view showing an example of the external appearance of the digital still camera 500, and Figure 31B is a rear view showing an example of the external appearance of the digital still camera 500. This digital still camera 500 is a single-lens reflex type with interchangeable lenses, and has an interchangeable shooting lens unit (interchangeable lens) 512 located approximately in the center of the front of the camera body 511, and a grip portion 513 for the photographer to hold on the left side of the front.

[0262] A monitor 514 is provided on the back of the camera body 511, slightly to the left of the center. An electronic viewfinder (eyepiece) 515 is provided above the monitor 514. The photographer can determine the composition by looking through the electronic viewfinder 515 and visually confirming the light image of the subject guided by the shooting lens unit 512. The display device 10 according to the embodiment of this disclosure can be used as the monitor 514 and the electronic viewfinder 515.

[0263] (Specific Example 2) Figure 32 is an external view of a head-mounted display 600. The head-mounted display 600 has, for example, an eyeglass-shaped display unit 611 and ear hooks 612 on both sides for attachment to the user's head. In this head-mounted display 600, the display device 10 according to the embodiment of this disclosure can be used as the display unit 611.

[0264] (Specific Example 3) Figure 33 is an external view of the see-through head-mounted display 634. The see-through head-mounted display 634 consists of a main body 632, an arm 633, and a lens barrel 631.

[0265] The main body 632 is connected to the arm 633 and the eyeglasses 630. Specifically, the long end of the main body 632 is connected to the arm 633, and one side of the main body 632 is connected to the eyeglasses 630 via a connecting member. The main body 632 may also be directly attached to the head of a person.

[0266] The main body 632 houses a control board for controlling the operation of the see-through head-mounted display 634 and a display unit. The arm 633 connects the main body 632 to the lens barrel 631 and supports the lens barrel 631. Specifically, the arm 633 is connected to the end of the main body 632 and the end of the lens barrel 631, respectively, and fixes the lens barrel 631 in place. The arm 633 also houses signal lines for communicating image-related data provided from the main body 632 to the lens barrel 631.

[0267] The lens barrel 631 projects image light, provided from the main body 632 via the arm 633, through the eyepiece lens towards the eyes of the user wearing the see-through head-mounted display 634. In this see-through head-mounted display 634, the display device 10 according to the embodiment of this disclosure can be used in the display section of the main body 632.

[0268] (Specific Example 4) Figure 34 shows an example of the appearance of a television device 710. This television device 710 has, for example, a video display screen section 711 including a front panel 712 and a filter glass 713, and this video display screen section 711 is configured with a display device 10 according to the embodiment of this disclosure.

[0269] (Specific Example 5) Figure 35 shows an example of the appearance of a smartphone 800. The smartphone 800 has a display unit 802 that displays various information, and an operation unit consisting of buttons, etc. that accept user input. The display unit 802 may be the display device 10 according to this embodiment.

[0270] (Specific Example 6) Figures 36A and 36B show the internal configuration of an automobile having a display device 10 according to the embodiment of this disclosure as a display device. More specifically, Figure 36A shows the interior of the automobile from the rear to the front, and Figure 36B shows the interior of the automobile from the diagonally rear to the diagonally front.

[0271] The automobile shown in Figures 36A and 36B includes a center display 911, a console display 912, a head-up display 913, a digital rear mirror 914, a steering wheel display 915, and a rear entertainment display 916. Some or all of these displays can be fitted with the display device 10 according to the embodiment of this disclosure.

[0272] The center display 911 is positioned on the center console 907, facing the driver's seat 901 and the passenger seat 902. Figures 36A and 36B show an example of a horizontally elongated center display 911 extending from the driver's seat 901 to the passenger seat 902, but the screen size and placement of the center display 911 are arbitrary. The center display 911 can display information detected by various sensors (not shown). As a specific example, the center display 911 can display images captured by an image sensor, distance images to obstacles in front of or to the side of the vehicle measured by a ToF (Time of Flight) sensor, and the body temperature of passengers detected by an infrared sensor. The center display 911 can be used to display, for example, at least one of safety-related information, operation-related information, life logs, health-related information, authentication / identification-related information, and entertainment-related information.

[0273] Safety-related information includes information such as drowsiness detection, distraction detection, detection of mischief by a passenger, seatbelt fastening status, and detection of an unattended occupant. This information is detected, for example, by a sensor (not shown) placed on top of the back of the center display 1911. Operation-related information is detected by sensing occupant gestures using sensors. The detected gestures may include the operation of various equipment in the vehicle. For example, the sensor detects the operation of air conditioning equipment, navigation systems, AV (Audio / Visual) systems, lighting systems, etc. Life logs include the life logs of all occupants. For example, life logs include records of each occupant's actions while riding in the vehicle. By acquiring and saving life logs, it is possible to confirm the state of the occupants at the time of an accident. Health-related information is detected by sensing the occupant's body temperature using a temperature sensor and inferring the occupant's health status based on the detected body temperature. Alternatively, the occupant's face may be captured using an image sensor, and the occupant's health status may be inferred from the facial expression captured. Furthermore, the system may engage in automated voice conversations with the occupants and infer their health status based on their responses. Authentication / identification-related information includes keyless entry functions that use sensors for facial recognition and functions that automatically adjust seat height and position based on facial recognition. Entertainment-related information includes functions that use sensors to detect information on how the occupants operate the AV equipment and functions that use sensors to recognize the occupants' faces and provide content suitable for the occupants through the AV equipment.

[0274] The console display 912 can be used, for example, to display life log information. The console display 912 is located near the shift lever 908 on the center console 907 between the driver's seat 901 and the passenger seat 902. The console display 912 can also display information detected by various sensors (not shown). In addition, the console display 912 may display an image of the area around the vehicle captured by an image sensor, or it may display an image showing the distance to obstacles around the vehicle.

[0275] The head-up display 913 is virtually displayed behind the windshield 904 in front of the driver's seat 901. The head-up display 913 can be used to display at least one of the following: safety-related information, operation-related information, life logs, health-related information, authentication / identification-related information, and entertainment-related information. Because the head-up display 913 is often virtually positioned in front of the driver's seat 901, it is suitable for displaying information directly related to the operation of the vehicle, such as the vehicle's speed and fuel (battery) level.

[0276] The digital rearview mirror 914 can not only display what is behind the vehicle, but also what is happening to the passengers in the rear seat. By placing a sensor (not shown) on top of the back of the digital rearview mirror 914, it can be used, for example, to display life log information.

[0277] The steering wheel display 915 is positioned near the center of the steering wheel 906 of the automobile. The steering wheel display 915 can be used to display at least one of the following: safety-related information, operation-related information, life log, health-related information, authentication / identification-related information, and entertainment-related information. In particular, because the steering wheel display 915 is located near the driver's hands, it is suitable for displaying life log information such as the driver's body temperature, or information related to the operation of AV equipment, air conditioning equipment, etc.

[0278] The rear entertainment display 916 is mounted on the back of the driver's seat 901 and the passenger seat 902, and is intended for viewing by rear-seat passengers. The rear entertainment display 916 can be used to display at least one of the following: safety-related information, operation-related information, life logs, health-related information, authentication / identification-related information, and entertainment-related information. In particular, because the rear entertainment display 916 is in front of the rear-seat passengers, it displays information relevant to the rear-seat passengers. For example, it may display information related to the operation of AV equipment or air conditioning equipment, or it may display the results of measurements of the rear-seat passengers' body temperature, etc., taken by a temperature sensor (not shown).

[0279] <<13. Supplementary Information>> Although preferred embodiments of the present disclosure have been described in detail with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person with ordinary skill in the art of the present disclosure may conceive of various modifications or alterations within the scope of the technical ideas described in the claims, and these will naturally also fall within the technical scope of the present disclosure.

[0280] Furthermore, the effects described herein are merely descriptive or illustrative and not limiting. In other words, the technology relating to this disclosure may produce other effects that will be apparent to those skilled in the art from the description herein, in addition to or in lieu of the effects described herein.

[0281] Furthermore, this technology can also take the following configurations: (1) A display device comprising a plurality of light-emitting elements arranged in a matrix on a substrate and emitting light of different wavelengths from each other, wherein each light-emitting element has a laminated structure consisting of a lower electrode, a light-emitting layer provided on the lower electrode, an upper electrode provided on the light-emitting layer, and a protective film provided on the upper electrode, and a sidewall film covering the side surface of the laminated structure, wherein in at least two of the plurality of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases. (2) The display device according to (1) above, wherein each light-emitting element has a laminated structure separated from each other. (3) The display device according to (1) or (2) above, wherein the sidewall film consists of one or more layers, and in the two light-emitting elements, the number of layers of the sidewall film decreases as the wavelength of the light increases. (4) In all of the plurality of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases, the display device according to (1) or (2) above. (5) The sidewall film consists of one layer or a plurality of layers, and in the plurality of light-emitting elements, the number of layers of the sidewall film decreases as the wavelength of the light increases, the display device according to (4) above. (6) The cross section of each light-emitting element cut along the stacking direction of the laminated structure has a tapered shape that widens from the upper surface to the lower surface of the laminated structure, and in the plurality of light-emitting elements, the taper angle of the cross section decreases as the wavelength of the light increases, the display device according to (4) or (5) above. (7) The display device according to any one of (4) to (6) above, wherein the area of ​​each of the multiple light-emitting elements, when viewed from above the substrate, decreases as the wavelength of the light increases.(8) The display device according to (7), wherein the upper electrodes of adjacent light-emitting elements are electrically connected via wiring extending over the plurality of light-emitting elements. (9) The display device according to (8), wherein the protective film has an opening that exposes the upper surface of the upper electrode, and the upper electrodes of adjacent light-emitting elements are electrically connected to each other via wiring extending over the upper surface of the protective film and the inner wall of the opening. (10) The display device according to (9), wherein in the plurality of light-emitting elements, the diameter of the opening decreases as the wavelength of the light increases. (11) The display device according to (9) or (10), wherein in the plurality of light-emitting elements, the film thickness of the protective film is the same. (12) The display device according to any one of (9) to (11), wherein the opening is filled with a material having a higher refractive index than the protective film. (13) The display device according to any one of (1) to (12), wherein the film thickness of the lower electrode is the same among the plurality of light-emitting elements. (14) The display device according to any one of (4) to (13), wherein at least a portion of the upper surface of the lower electrode is covered with a lower electrode protective film. (15) The display device according to (14), wherein in the plurality of light-emitting elements, the thickness of the lower electrode protective film decreases as the wavelength of the light increases. (16) The display device according to any one of (1) to (15), wherein each of the light-emitting elements has a polygonal, circular, or elliptical shape when viewed from above the substrate. (17) The display device according to any one of (1) to (16), wherein the plurality of light-emitting elements are arranged in a stripe pattern, a square pattern, or a delta pattern when viewed from above the substrate. (18) The display device according to any one of (1) to (3) above, wherein the plurality of light-emitting elements include a plurality of three types of light-emitting elements that emit light having different wavelengths from each other, and in the relationship between two of the three types of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases.(19) The display device according to (18), wherein, in the plurality of light-emitting elements, when the wavelength of light emitted from the corresponding light-emitting layer is λ, the phase shift Φ due to reflection at the upper electrode and the lower electrode is an integer m, the optical distance L between the upper electrode and the lower electrode satisfies the resonance condition shown by the following formula (1), and in at least one of the three types of light-emitting elements, the integer m is 0. λ: Emission peak wavelength λ of the light-emitting layer corresponding to each of the light-emitting elements Φ: Phase shift (radians) between the upper electrode and the lower electrode m: Integer (20) The display device according to (19) above, wherein the integer m is the same for two of the three types of light-emitting elements. (21) The display device according to (20) above, wherein the integer m is 1 for two of the three types of light-emitting elements. (22) The three types of multiple light-emitting elements include a first light-emitting element that emits the shortest wavelength of light, a second light-emitting element that emits the second longest wavelength of light, and a third light-emitting element that emits the longest wavelength of light, wherein the thickness of the light-emitting layer increases in the order of the third light-emitting element, the first light-emitting element, and the second light-emitting element, the thickness of the sidewall film decreases in the order of the third light-emitting element, the first light-emitting element, and the second light-emitting element, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases in the order of the third light-emitting element, the first light-emitting element, and the second light-emitting element, the display device according to (21) above. (23) The two types of light-emitting elements among the three types of light-emitting elements are 0, the display device according to (20) above. (24) The three types of multiple light-emitting elements include a first light-emitting element that emits the shortest wavelength of light, a second light-emitting element that emits the second longest wavelength of light, and a third light-emitting element that emits the longest wavelength of light, wherein the thickness of the light-emitting layer increases in the order of the second light-emitting element, the third light-emitting element, and the first light-emitting element, the thickness of the sidewall film decreases in the order of the second light-emitting element, the third light-emitting element, and the first light-emitting element, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases in the order of the second light-emitting element, the third light-emitting element, and the first light-emitting element, the display device according to (23) above.(25) The display device according to any one of (1) to (5) above, wherein the plurality of light-emitting elements include a first light-emitting element, a second light-emitting element, and a third light-emitting element, and when viewed from above the substrate, in one pixel unit, the first and second light-emitting elements are arranged alternately so as to surround the third light-emitting element, and in the first and second light-emitting elements or the third light-emitting element, the length of the axis along the first direction of its planar shape is different from the length of the axis along the second direction of the planar shape that intersects perpendicularly with the first direction. (26) The display device according to (25) above, wherein the plurality of pixel units are arranged in a matrix in the pixel array, and when viewed from above the substrate, in the first and second light-emitting elements or the third light-emitting element, the length of the axis along the column direction of its planar shape is different from the length of the axis along the row direction of the planar shape. (27) The display device according to (26) above, wherein the length of the axis in the column direction of the first and second light-emitting elements is longer than the length of the axis in the row direction. (28) The display device according to (27), wherein the planar shapes of the first and second light-emitting elements are symmetrical with respect to an axis along the column direction passing through the centers of the first and second light-emitting elements, and are not symmetrical with respect to an axis along the row direction passing through the centers of the first and second light-emitting elements. (29) The display device according to (28), wherein, when viewed from above the substrate, the length of the side where the first light-emitting element and the second light-emitting element face each other is longer than the side where the third light-emitting element and the first light-emitting element face each other, and the side where the third light-emitting element and the second light-emitting element face each other. (30) The display device according to (27), wherein the planar shapes of the first and second light-emitting elements are teardrop-shaped, elliptical, trapezoidal, isosceles triangular, or pentagonal or hexagonal. (31) The display device according to any one of (26) to (30), wherein the length of the axis of the third light-emitting element in the column direction is shorter than the length of the axis in the row direction.(32) The display device according to (31), wherein the planar shape of the third light-emitting element is symmetrical with respect to an axis along the column direction passing through the center of the third light-emitting element, and is symmetrical with respect to an axis along the row direction passing through the center of the third light-emitting element. (33) The display device according to (32), wherein the planar shape of the third light-emitting element is circular, elliptical, square, rectangular, hexagonal, or cross-shaped. (34) The display device according to any one of (26) to (33), wherein, when viewed from above the substrate, each of the first and second light-emitting elements is arranged at a predetermined distance from the third light-emitting element. (35) The display device according to any one of (26) to (34), wherein, when viewed from above the substrate, in the pixel unit, the first and second light-emitting elements are arranged in a relationship that is symmetrical with respect to an axis along the row direction passing through the center of the pixel unit. (36) The display device according to any one of (26) to (35) above, wherein, when viewed from above the substrate, the area of ​​the third light-emitting element is smaller than that of the first and second light-emitting elements. (37) The display device according to any one of (1) to (24) above, wherein each of the light-emitting elements further comprises an on-chip lens. (38) The display device according to (37) above, wherein each of the light-emitting elements further comprises a color filter that transmits the light emitted from the light-emitting layer. (39) The display device according to (38) above, wherein the plurality of light-emitting elements are arranged in a matrix in the pixel array, and the position of the center of the light-emitting element and the position of the center of the on-chip lens are offset according to the position of the light-emitting element within the pixel array.(40) A display device comprising a plurality of light-emitting elements arranged on a substrate and emitting light of different wavelengths from each other, wherein the plurality of light-emitting elements include a first light-emitting element, a second light-emitting element, and a third light-emitting element, wherein, when viewed from above the substrate, in one pixel unit, the first and second light-emitting elements are arranged alternately so as to surround the third light-emitting element, and in the first and second light-emitting elements, or the third light-emitting element, the length of the axis along the first direction of its planar shape is different from the length of the axis along the second direction of the planar shape that intersects perpendicularly with the first direction. (41) A method for manufacturing a display device comprising first, second, and third light-emitting elements arranged in a matrix on a substrate, separated from each other, and emitting light of different wavelengths, comprising: forming a first lower electrode, a second lower electrode, and a third lower electrode on the substrate; sequentially laminating a first light-emitting layer, a first upper electrode, and a first protective film on the first lower electrode to form a first light-emitting element; sequentially laminating a second light-emitting layer, a second upper electrode, and a second protective film on the second lower electrode, and simultaneously laminating the second protective film so as to cover the side surface of the first light-emitting element to form a second light-emitting element; sequentially laminating a third light-emitting layer, a third upper electrode, and a third protective film on the third lower electrode, and simultaneously laminating the third protective film so as to cover the side surface of the first and second light-emitting elements to form a third light-emitting element, A method for manufacturing a display device, wherein, in the relationship between at least the first light-emitting element and the second light-emitting element, the wavelength of the light emitted by the second light-emitting element is longer than that of the first light-emitting element, or, in the relationship between at least the second light-emitting element and the third light-emitting element, the wavelength of the light emitted by the third light-emitting element is longer than that of the second light-emitting element.(42) Electronic device equipped with a display device, wherein the display device comprises a plurality of light-emitting elements arranged in a matrix on a substrate and emitting light of different wavelengths from each other, each light-emitting element having a laminated structure consisting of a lower electrode, a light-emitting layer provided on the lower electrode, an upper electrode provided on the light-emitting layer, and a protective film provided on the upper electrode, and a sidewall film covering the side surface of the laminated structure, wherein in at least two of the plurality of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases.

[0282] 10 Display device 11 Horizontal drive circuit 12 Vertical drive circuit 20, 20a Pixel 40 Substrate 100, 100B, 100G, 100R Subpixel 112, 112a, 112b, 112c, 112g, 112r Light-emitting element 200, 200a, 200b, 200g, 200r Anode electrode 210, 210a, 210b, 210c, 210g, 210r Light-emitting layer 220, 220a, 220b, 220g, 220r Cathode electrode 230, 232, 240, 242, 244, 270 Protective film 250 Aperture 252 Wiring 260, 264 Planarization film 262, 262b, 262g, 262r Color filter 266 On-chip lens 280, 280b, 280g, 280r Anode protective film 300 Vignetting 400, 402 Resist 410, 420 Center 412, 414 Axis

Claims

1. A display device comprising a plurality of light-emitting elements arranged in a matrix on a substrate and emitting light of different wavelengths from each other, wherein each light-emitting element has a laminated structure consisting of a lower electrode, a light-emitting layer provided on the lower electrode, an upper electrode provided on the light-emitting layer, and a protective film provided on the upper electrode, and a sidewall film covering the side surface of the laminated structure, wherein in at least two of the plurality of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases.

2. The display device according to claim 1, wherein each of the light-emitting elements has a stacked structure that is separated from each other.

3. The sidewall film consists of one or more layers, and in the two light-emitting elements, the number of layers of the sidewall film decreases as the wavelength of the light increases, the display device according to claim 1.

4. The display device according to claim 1, wherein in all of the plurality of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases.

5. The display device according to claim 4, wherein the sidewall film consists of one or more layers, and in the plurality of light-emitting elements, the number of layers of the sidewall film decreases as the wavelength of the light increases.

6. The display device according to claim 4, wherein the cross-section of each of the light-emitting elements, when cut along the stacking direction of the stacked structure, has a tapered shape that widens from the top surface to the bottom surface of the stacked structure, and in the plurality of light-emitting elements, the taper angle of the cross-section decreases as the wavelength of the light increases.

7. In the plurality of light-emitting elements, the area of ​​each light-emitting element as viewed from above the substrate decreases as the wavelength of the light increases, the display device according to claim 4.

8. The display device according to claim 7, wherein the upper electrodes of adjacent light-emitting elements are electrically connected via wiring extending over the plurality of light-emitting elements.

9. The display device according to claim 8, wherein the protective film has an opening that exposes the upper surface of the upper electrode, and the upper electrodes of adjacent light-emitting elements are electrically connected to each other via the wiring that extends from the upper surface of the protective film and the inner wall of the opening.

10. The display device according to claim 9, wherein in the plurality of light-emitting elements, the diameter of the aperture decreases as the wavelength of the light increases.

11. The display device according to claim 1, wherein the plurality of light-emitting elements include a plurality of three types of light-emitting elements that emit light having different wavelengths from each other, and in the relationship between two of the three types of light-emitting elements, the thickness of the light-emitting layer increases as the wavelength of the light emitted from the light-emitting layer increases, the thickness of the sidewall film decreases as the wavelength of the light increases, and the height of the upper surface of the laminated structure relative to the upper surface of the substrate increases as the wavelength of the light increases.

12. The display device according to claim 11, wherein, in the plurality of light-emitting elements, when the wavelength λ of light emitted from the corresponding light-emitting layer, the phase shift Φ due to reflection at the upper electrode and the lower electrode is an integer m, the optical distance L between the upper electrode and the lower electrode satisfies the resonance condition shown by the following formula (1), and in at least one of the three types of light-emitting elements, the integer m is 0. λ: Emission peak wavelength λ of the light-emitting layer corresponding to each light-emitting element Φ: Phase shift (radians) between the upper electrode and the lower electrode m: Integer 13. The display device according to claim 12, wherein in two of the three types of light-emitting elements, the integer m is 1.

14. The display device according to claim 12, wherein in two of the three types of light-emitting elements, the integer m is 0.

15. The display device according to claim 1, wherein the plurality of light-emitting elements include a first light-emitting element, a second light-emitting element, and a third light-emitting element, and when viewed from above the substrate, in one pixel unit, the first and second light-emitting elements are arranged alternately so as to surround the third light-emitting element, and in the first and second light-emitting elements, or the third light-emitting element, the length of the axis along the first direction of its planar shape is different from the length of the axis along the second direction that intersects the first direction perpendicularly with the planar shape.

16. The display device according to claim 15, wherein the plurality of pixel units are arranged in a matrix in the pixel array, and when viewed from above the substrate, the length of the axis along the column direction of the planar shape of the first and second light-emitting elements, or the third light-emitting element, is different from the length of the axis along the row direction of the planar shape.

17. The display device according to claim 16, wherein the length of the axis in the column direction of the first and second light-emitting elements is longer than the length of the axis in the row direction.

18. The display device according to claim 17, wherein the planar shapes of the first and second light-emitting elements are symmetrical with respect to an axis along the column direction passing through the centers of the first and second light-emitting elements, and are not symmetrical with respect to an axis along the row direction passing through the centers of the first and second light-emitting elements.

19. When viewed from above the substrate, the length of the side on which the first light-emitting element and the second light-emitting element face each other is longer than the length of the side on which the third light-emitting element and the first light-emitting element face each other, and the length of the side on which the third light-emitting element and the second light-emitting element face each other, as described in claim 18.

20. The display device according to claim 16, wherein the length of the axis in the column direction of the third light-emitting element is shorter than the length of the axis in the row direction.

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