DISPLAY DEVICE

Abstract

A display device (100) comprises a plurality of first electrodes (161) and a contact electrode (163) on a substrate (110); a plurality of light-emitting elements (10) on the plurality of first electrodes (161); a first optical layer (141) between the plurality of light-emitting elements (10); and a second electrode (170) on the plurality of light-emitting elements (10), wherein the second electrode (170) comprises a first region (171) located on the plurality of light-emitting elements (10) and a second region (172) extending beyond an end of the first optical layer (141) and in contact with the contact electrode (163).

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority and privilege from Patent Application No. 10-2023-0090571 filed in the Republic of Korea on July 12, 2023. Technical area

[0002] The present disclosure relates to a display device, particularly, without limitation, to a display device using an inorganic light emitting diode as a light emitting element. Discussion of the related prior art

[0003] An electroluminescent display device includes an organic light-emitting display device in which an organic light-emitting diode (OLED) is arranged, and an inorganic light-emitting display device (hereinafter referred to as "LED display device") in which an inorganic light-emitting diode (hereinafter referred to as "LED") is arranged.

[0004] The electroluminescent display device displays images using self-luminous elements and therefore does not require a separate light source, such as a backlight, and can be thin and made in various shapes.

[0005] Since an oxidation phenomenon may occur between an organic light-emitting layer and an electrode in the organic light-emitting display device due to the penetration of moisture and oxygen, a design for preventing or reducing the penetration of oxygen and moisture is required.

[0006] As an example of an inorganic light-emitting display device, a microLED display device, in which microLEDs are arranged in pixels, has recently attracted attention as a next-generation display device. The microLED can be an inorganic LED with a size of 100 µm or less. MicroLEDs are fabricated in a separate semiconductor process and transferred to pixel positions on a display panel substrate of the display device, allowing them to be arranged in respective sub-pixels for each color. SUMMARY

[0007] In the prior art, each micro-LED may be connected to an anode electrode and a cathode electrode to receive power. However, the inventors of the present disclosure have recognized that in a process where the cathode electrode is connected to a low-potential voltage, a step is generated, and stress is concentrated in a part where the step is generated, causing cracks to develop.

[0008] Therefore, the inventors of the present disclosure recognized the above-mentioned problems and other limitations associated with the prior art and conducted various experiments to realize a display panel capable of preventing or reducing the occurrence of cracks in a cathode electrode and a display device incorporating the same.

[0009] Additional features and aspects of the disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by application of the inventive concepts contained herein. Other features and aspects of the inventive concepts may be realized and attained by the structures pointed out or derivable from the present disclosure, the claims, and the appended drawings.

[0010] To achieve these and other aspects of the inventive concepts as embodied and generally described herein, a display device includes: a substrate; a plurality of first electrodes on the substrate; a contact electrode on the substrate; a plurality of light-emitting elements on the plurality of first electrodes; a first optical layer between the plurality of light-emitting elements; and a second electrode on the plurality of light-emitting elements, the second electrode including a first region located on the plurality of light-emitting elements and a second region extending beyond an end of the first optical layer and in contact with the contact electrode.

[0011] In one embodiment, a display device comprises: a substrate; a plurality of first electrodes on the substrate; a plurality of light-emitting elements on the plurality of first electrodes; a first optical layer between the plurality of light-emitting elements; a second electrode on the plurality of light-emitting elements, the second electrode having a first region located on the plurality of light-emitting elements and a second region extending beyond an end of the first optical layer; and a second optical layer surrounding the first optical layer, the second optical layer lying on the second region of the second electrode.

[0012] In one embodiment, a display device comprises: a substrate; a first electrode on the substrate; a contact electrode on the substrate and including a portion extending in a first direction, the contact electrode configured to provide a voltage; a light-emitting element on the first electrode; a first optical layer surrounding the light-emitting element; and a second electrode configured to provide the voltage from the contact electrode to the light-emitting element, the second electrode including a first portion connected to the light-emitting element and extending in the first direction, and a second portion extending in the first direction and in contact with the portion of the contact electrode extending in the first direction, without the first optical layer overlying the second portion of the second electrode.

[0013] According to embodiments of the present disclosure, the occurrence of cracks in a cathode electrode can be prevented or reduced.

[0014] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to further explain the inventive concepts claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which may be included to provide a further understanding of the disclosure and which are incorporated in and constitute a part of the disclosure, illustrate embodiments of the disclosure and, together with the description, serve to explain various principles of the disclosure.

[0016] The above and other aspects, features and advantages of the present disclosure will become more apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings, in which: Fig. 1 is a view illustrating a display device according to an exemplary embodiment of the present specification; Fig. Figure 2 is an enlarged view showing area A in Fig. 1 illustrates, according to the exemplary embodiment of the present description; Fig. 3 is a view illustrating a portion of a pixel according to the embodiment of the present description; Fig. 4 is a cross-sectional view taken along line II' in Fig. 3 according to the embodiment of the present description; Fig. 5 is a cross-sectional view along the line II-II' in Fig. 3 according to the embodiment of the present description; Fig. 6 is a cross-sectional view taken along the line III-III' in Fig. 3 according to the embodiment of the present description; Fig. 7 is a cross-sectional view illustrating an example in which a main light-emitting element and a sub-light-emitting element are electrically connected to a pixel driving circuit according to an exemplary embodiment of the present specification; Fig. 8 is a view illustrating a display device according to another exemplary embodiment of the present specification; Fig. 9 is a cross-sectional view along the line IV-IV' in Fig. 8 according to the embodiment of the present description; Fig. 10 is a view illustrating a state in which stress is concentrated in a second electrode disposed in a through hole; Fig. 11 is a first modified example of Fig. 8 according to an exemplary embodiment of the present description; Fig. 12 is a second modified example of Fig. 8 according to an exemplary embodiment of the present description; and Fig. 13A to 13F are views illustrating a method of manufacturing a display device according to an exemplary embodiment of the present specification.

[0017] Unless otherwise described, the same reference numerals in the drawings and the detailed description refer to the same elements, features, and structures. The relative size and representation of these elements may be exaggerated for clarity, illustration, and convenience. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to embodiments of the present disclosure, examples of which may be illustrated in the accompanying drawings. In the following description, a detailed description of well-known functions or configurations related to the present document is omitted if doing so would unnecessarily obscure the essence of the inventive concept. The described sequence of processing steps and / or processes is an example; however, the sequence of steps and / or processes is not limited to the sequence set forth herein and may be changed according to the prior art, except for steps and / or processes that necessarily occur in a particular order. Like reference numerals denote like elements throughout.The names of the respective elements used in the following explanations were chosen only for the sake of simplicity of description and may therefore differ from those used in actual products.

[0019] Advantages and features of the present disclosure, as well as methods for implementing them, will become apparent from the following embodiments, which are described in detail in conjunction with the accompanying drawings. The present disclosure is not limited to the embodiments described below and may be embodied in various forms. The exemplary embodiments are provided merely to fully disclose the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art, and the present disclosure is defined by the scope of the appended claims. Any embodiment described herein as an "example" is not necessarily to be construed as preferred or advantageous over other implementations.

[0020] Since the shapes, sizes, proportions, angles, numbers, and the like disclosed in the drawings for describing embodiments of the present disclosure are only examples, the present disclosure is not limited to the elements shown in the drawings. Throughout the description, the same reference numerals refer to substantially the same components. When describing the present disclosure, it is determined that a detailed description of related known technologies might unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted or presented briefly.

[0021] When using terms such as "supply," "include," "have," "comprises," and the like mentioned in this specification, other parts may be added unless terms such as "only" are used. A case where a component is expressed in the singular may also be interpreted as a plural, unless expressly stated otherwise.

[0022] When interpreting the components, it is important to note that an error area is included even if it is not explicitly described.

[0023] When a positional relationship and a connecting relationship between two parts is described such as "on", "at an upper part", "at a lower part", "adjacent", "connecting or coupling", "crossing or intersecting" or the like, one or more other parts may be arranged between the parts unless a more restrictive term such as "immediate" or "direct" is used.

[0024] When a temporal relationship is described as "after," "following," "and then," "before," or the like, the temporal relationship cannot be continuous on a timeline unless a more restrictive term such as "just," "immediately," or "immediately" is used.

[0025] When describing elements of the present disclosure, terms such as "first," "second," "A," "B," "(a)," "(b)," and the like may be used before component names to distinguish the components, but the functions, structures, natures, order, sequence, or number of the corresponding components are not limited by these ordinal numbers or component names. For ease of description, the ordinal numbers before the name of the same component may be different in different embodiments.When an element or layer is described as being "connected", "coupled", or "adhered" to another element or layer, the element or layer may not only be directly connected or adhered to the other element or layer, but may also be indirectly connected or adhered to the other element or layer with one or more intermediate elements or layers "interposed" between the elements or layers, unless otherwise stated.

[0026] The term "at least one" is to be understood to include any and all combinations of one or more of the listed elements. For example, the meaning of "at least one of a first element, a second element, and a third element" includes the combination of all three listed elements, combinations of any two of the three elements, and each of the first element, the second element, or the third element.

[0027] The features of the various embodiments of the present disclosure may be partially or entirely coupled or combined with one another, and may interact and be technically controlled in various ways, as would be readily understood by those skilled in the art. Embodiments of the present disclosure may be implemented independently of one another or together in a codependent relationship.

[0028] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments belong. It is further understood that terms as defined in commonly used dictionaries should be interpreted to have a meaning consistent, for example, with their meaning in the context of the relevant prior art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.For example, the term "part" or "unit" may be applied to a separate circuit or structure, an integrated circuit, a computing block of a device, or any structure arranged to perform a described function as would be understood by a person skilled in the art.

[0029] Below, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, all components of each display device are operatively coupled and configured according to all embodiments of the present disclosure.

[0030] A display device according to an embodiment of the present description includes a display area in which an image is displayed, or a display panel on which a screen is arranged, and a panel drive circuit that drives the pixels of the display panel. The display area includes a pixel area in which the pixels are arranged. The pixel area includes a plurality of light-emitting areas. A light-emitting element is arranged in each of the light-emitting areas. The pixel drive circuit can be incorporated into the display panel.

[0031] Fig. 1 is a view illustrating the display device according to an exemplary embodiment of the present specification. Fig. Figure 2 is an enlarged view showing area A in Fig. 1 according to one embodiment. Fig. 3 is a view illustrating a portion of a pixel according to one embodiment.

[0032] With reference to Fig. 1 and Fig. 2, a display device 100 according to an exemplary embodiment of the present description includes a display panel on which an input image is visually displayed. The display panel may include a display area AA in which an image is displayed, and a non-display area NA in which the image is not displayed. The non-display area NA may be adjacent to the display area AA and, for example, may be arranged around the display area AA. Various wiring and drive circuits may be mounted in the non-display area NA, and a pad part PAD may be arranged to which an integrated circuit, a printed circuit, and the like is connected.

[0033] A plurality of light-emitting elements 10 arranged in the display area AA and forming pixels PXL may be micro-sized inorganic light-emitting elements. The inorganic light-emitting elements may be grown on a silicon wafer and then applied to the display panel through a transfer process.

[0034] The process of transferring the light-emitting elements 10 can be carried out for each previously divided area. Fig. 1 describes an example in which the display area AA is divided into nine transmission areas ST, but the size or number of the divided transmission areas is not limited thereto. The transmission process can be performed sequentially or simultaneously for the first to ninth transmission areas ST. A blue light-emitting element 10, a green light-emitting element 10, and a red light-emitting element 10 can be successively transmitted into each transmission area ST.

[0035] Data drive circuits or gate drive circuits may be arranged in the non-display area NA, and lines to which control signals for driving these drive circuits are supplied may be arranged. Here, the control signals may include various timing signals, including clock signals, input data enable signals, and synchronization signals, and may be received via the pad part PAD. However, the present disclosure is not limited to this. For example, at least one of the data drive circuits and the gate drive circuits may be arranged on a lower surface of the display panel and connected to the pixels within the display area AA via the pad part PAD, thereby reducing or minimizing the size or area of ​​the non-display area NA. In another example, the gate drive circuits may be integrated into the display area AA.

[0036] The pixels PXL can be driven by the pixel drive circuit. The pixel drive circuit can receive a drive voltage, an image signal (e.g., a data signal), a synchronization signal synchronized with the image signal, and the like, and output an anode voltage and a cathode voltage of the light-emitting element 10 to drive a plurality of pixels. The drive voltage can be a high-potential voltage EVDD. The cathode voltage can be a low-potential voltage EVSS commonly applied to the pixels. The anode voltage can be a voltage corresponding to a pixel data value of the image signal. The pixel drive circuit can be arranged in the non-display area NA or below the display area AA.

[0037] Each pixel PXL may include a plurality of sub-pixels with different colors. For example, each of the plurality of pixels may include a red sub-pixel in which the light-emitting element 10 emitting light with a red wavelength is arranged, a green sub-pixel in which the light-emitting element 10 emitting light with a green wavelength is arranged, and a blue sub-pixel in which the light-emitting element 10 emitting light with a blue wavelength is arranged. The plurality of pixels may further include a white sub-pixel.

[0038] With reference to Fig. 2 and Fig. 3, the plurality of pixels PXL may be arranged continuously in a first direction (an X-axis direction) and a second direction (a Y-axis direction). A plurality of sub-pixels of the same color may be arranged in the pixel of the display area AA.For example, each of the plurality of pixels may include a first red sub-pixel in which a 1-1 light-emitting element 11a is arranged that emits light with a red wavelength, a second red sub-pixel in which a 1-2 light-emitting element 11b is arranged that emits light with a red wavelength, a first green sub-pixel in which a 2-1 light-emitting element 12a is arranged that emits light with a green wavelength, a second green sub-pixel in which a 2-2 light-emitting element 12b is arranged that emits light with a green wavelength, a first blue sub-pixel in which a 3-1 light-emitting element 13a is arranged that emits light with a blue wavelength, and a second blue sub-pixel in which a 3-2 light-emitting element 13b is arranged that emits light with blue wavelength.The 1-1 light-emitting element 11a, the 2-1 light-emitting element 12a, and the 3-1 light-emitting element 13a can be referred to as main light-emitting elements. The 1-2 light-emitting element 11b, the 2-2 light-emitting element 12b, and the 3-2 light-emitting element 13b can be referred to as sub-light-emitting elements or redundant light-emitting elements.

[0039] A sub-pixel may include at least one or more light-emitting elements, so that when one light-emitting element becomes defective, the luminance of the sub-pixel can be adjusted by increasing the luminance of the other light-emitting elements. However, the present disclosure is not necessarily limited thereto, and a sub-pixel may also include only one light-emitting element.

[0040] A plurality of first electrodes 161 may be arranged below the light-emitting elements 10, respectively, and selectively connected to a plurality of signal lines TL1 to TL6 via a portion 161a. The high-potential voltage may be applied to the pixel drive circuit via the signal lines TL1 to TL6. The signal lines TL1 to TL6 and the first electrodes 161 may be formed as an integrated electrode structure during an electrode patterning process.

[0041] For example, a first signal line TL1 may be connected to an anode electrode of the first red sub-pixel, and a second signal line TL2 may be connected to an anode electrode of the second red sub-pixel. A third signal line TL3 may be connected to an anode electrode of the first green sub-pixel, and a fourth signal line TL4 may be connected to an anode electrode of the second green sub-pixel. A fifth signal line TL5 may be connected to an anode electrode of the first blue sub-pixel, and a sixth signal line TL6 may be connected to an anode electrode of the second blue sub-pixel. When a sub-pixel contains only one light-emitting element, the number of signal lines TL can be reduced by half.

[0042] A second electrode 170 may be a cathode electrode arranged in each row and applying a cathode voltage to the light-emitting elements 10 arranged continuously in the first direction (the X-axis direction). The plurality of second electrodes 170 may be arranged to be spaced apart from each other in the second direction (the Y-axis direction). The plurality of second electrodes 170 may receive the cathode voltage via a contact electrode 163. Each of the plurality of second electrodes 170 may be electrically connected to the contact electrode 163. However, the present disclosure is not necessarily limited to this, and the second electrode 170 may not be divided into the plurality of second electrodes 170 and may be configured as a single electrode layer and function as a common electrode.

[0043] Fig. 4 is a cross-sectional view taken along line II' in Fig. 3 according to one embodiment. Fig. 5 is a cross-sectional view along the line II-II' in Fig. 3 according to one embodiment. Fig. 6 is a cross-sectional view taken along the line III-III' in Fig. 3 according to one embodiment. Fig. 7 is a cross-sectional view illustrating an example in which two light-emitting elements are connected to the pixel driving circuit according to an embodiment.

[0044] With reference to Fig. 3 to 5, the display device according to the embodiment includes the plurality of first electrodes 161 and the contact electrode 163 arranged on a substrate 110, the plurality of light-emitting elements 10 arranged on the plurality of first electrodes 161, a first optical layer 141 arranged between the plurality of light-emitting elements 10, and the second electrode 170 arranged on the plurality of light-emitting elements 10.

[0045] The substrate 110 may include a flexible plastic. The substrate 110 may be fabricated, for example, as a single- or multi-layer substrate made of a material selected from, but not limited to, polyimide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, polyarylate, polysulfone, and a cyclic olefin copolymer. The substrate 110 may be, for example, a ceramic or glass substrate.

[0046] A pixel drive circuit 20 may be arranged in the display area AA on the substrate 110. The pixel drive circuit 20 may include a plurality of thin-film transistors using an amorphous silicon semiconductor, a polycrystalline silicon semiconductor, or an oxide semiconductor as the active layer material.

[0047] The pixel drive circuit 20 may include at least one drive thin-film transistor, at least one switching thin-film transistor, and at least one storage capacitor. The pixel drive circuit 20 may be formed on the substrate 110 using a thin-film transistor (TFT) manufacturing process if it includes a plurality of thin-film transistors. In the embodiment, the pixel drive circuit 20 for pixels may be a concept that collectively refers to a plurality of thin-film transistors electrically connected to the light-emitting elements 10.

[0048] The pixel drive circuit 20 may be a pixel driver fabricated on a single-crystal semiconductor substrate 110 using a metal-oxide-silicon field-effect transistor (MOSFET) manufacturing process. The pixel driver may include a plurality of pixel drive circuits to drive a plurality of sub-pixels. When the pixel drive circuit 20 is implemented as a pixel driver, the pixel driver may be attached to the adhesive layer by the transfer process after an adhesive layer is disposed on the substrate 110.

[0049] A buffer layer 121 may be disposed on the substrate 110, covering the pixel drive circuit 20. The buffer layer 121 may include an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide.

[0050] The buffer layer 121 can be used by using an inorganic insulating material, e.g., silicon nitride (SiN x ), silicon oxide (SiO2) or the like, or by multi-layering an organic insulating material and an inorganic insulating material.

[0051] An insulating layer 122 may be disposed on the buffer layer 121. The insulating layer 122 may include an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide. Interconnection lines RT1 and RT2 may be disposed on the buffer layer 121. The interconnection lines RT1 and RT2 may be connected to the corresponding signal lines TL1 to TL6 or may be connected to the signal lines TL1 to TL6. The interconnection lines RT1 and RT2 may include a plurality of structures disposed on different layers with one or more insulating layers disposed therebetween. The conductive structures disposed on the different layers may be electrically connected by vias passing through the insulating layer.

[0052] A plurality of bank structures 130 may be arranged on the insulating layer 122. At least one light-emitting element 10 may be arranged on an upper surface of each bank structure 130. For example, a first light-emitting element 11 may be arranged on a first bank structure 130, a second light-emitting element 12 may be arranged on a second bank structure 130, and a third light-emitting element 13 may be arranged on a third bank structure 130. As shown in Fig. 4, a first electrode 161 is located on an upper surface of a bank structure 130 such that the first electrode 161 is located between the bank structure 130 and a light-emitting element 10.

[0053] The bank structure 130 may include an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide. The bank structure 130 may specify a position where the light-emitting elements 10 are mounted during the transfer process of the light-emitting elements 10. The bank structure 130 may also be omitted.

[0054] A solder structure 162 may be disposed on the first electrode 161. The solder structure 162 may include, but is not limited to, indium (In), tin (Sn), or an alloy thereof. The solder structure 162 may also be referred to as a conductive interconnect structure / layer or a conductive adhesive structure / layer. However, the present disclosure is not limited thereto, and the solder structure 162 may be omitted.

[0055] Each of the plurality of light-emitting elements 10 can be mounted on the solder structure 162. A pixel can include light-emitting elements 10 in three colors. The first light-emitting element 11 can be a red light-emitting element, the second light-emitting element 12 can be a green light-emitting element, and the third light-emitting element 13 can be a blue light-emitting element. Two light-emitting elements can be mounted in each sub-pixel.

[0056] The first optical layer 141 may cover the plurality of light-emitting elements 10 and the bank structure 130. Accordingly, the first optical layer 141 may cover a space between the plurality of light-emitting elements 10 and a portion of a space between the plurality of bank structures 130. The first optical layers 141 may extend in the first direction (X) and be spaced apart from each other in the second direction (Y) to be separated between pixel rows.

[0057] The first optical layer 141 may contain an organic insulating material in which light-scattering particles, for example, but not exclusively, fine metal particles such as titanium dioxide particles, are dispersed. The light emitted by the plurality of light-emitting elements 10 may be scattered by the fine metal particles dispersed in the first optical layer 141 and emitted outward.

[0058] The second electrode 170 may be arranged on the plurality of light-emitting elements 10. The second electrode 170 may be commonly connected to the plurality of pixels PXL. That is, the second electrode 170 may be connected to multiple pixels PXL. The second electrode 170 may be a thin electrode that transmits light. The second electrode 170 may include a transparent electrode material, such as, but is not necessarily limited to, indium tin oxide (ITO).

[0059] The second electrode 170 may extend in the first direction (the X-axis direction) and be spaced apart in the second direction (the Y-axis direction). The second electrode 170 may include a first region 171 (e.g., a first section or a first part) disposed on a top surface of the light-emitting element 10 and a top surface of the first optical layer 141 at a first height with respect to the substrate 110, a second region 172 (e.g., a second section or a second part) at a second height lower than the first height with respect to the substrate 110 and in contact with a part of the contact electrode 163 and electrically connected to the contact electrode 163, and a third region 173 (e.g., a third section or a third part) disposed on a side surface of the first optical layer 141 and connecting the first region 171 and the second region 172.In one embodiment, the third region 173 is inclined with respect to the substrate 110. In one embodiment, the first region 171 of the second electrode 170, the second region 172 of the second electrode 170, and the part of the contact electrode 163 that is in contact with the second region 172 of the second electrode 170 extend in a first direction (e.g., a horizontal direction). As shown in FIG. Fig. 4, the second region 172 of the second electrode 170 extends beyond one end of the third region 173 so that the first optical layer 141 does not overlie the second region 172 of the second electrode 170.

[0060] Each of the plurality of second electrodes 170 may overlap the first optical layer 141 in a plane, and the second region 172 may cover a plane outside the first optical layer 141.

[0061] A second optical layer 142 may be an organic insulating material surrounding the first optical layer 141. The second optical layer 142 may be disposed on the insulating layer 142 together with the first optical layer 141. The second optical layer 142 may not contain the fine metal particles in the first optical layer 141. The first optical layer 141 and the second optical layer 142 may contain the same material (e.g., siloxane). For example, the first optical layer 141 may be made of siloxane containing titanium oxide (TiO x ), and the second optical layer 142 may be made of siloxane that does not contain titanium oxide (TiO x). However, the present disclosure is not necessarily limited thereto, and the first optical layer 141 and the second optical layer 142 may be formed of the same material or different materials. That is, the first optical layer 141 contains a first material, and the second optical layer 142 contains a second material different from the first material.

[0062] According to the embodiment, since the second region 172 of the second electrode 170 is connected to the part of the contact electrode 163 in a generally flat state, excessive stress is not concentrated at a point connected to the contact electrode 163. Accordingly, it is possible to effectively prevent or reduce the occurrence of cracks in the second electrode 170. That is, a part of the contact electrode 163 extends in the horizontal direction, and a part of the second region 172 of the second electrode 170 that is in contact with the part of the contact electrode 163 also extends in the horizontal direction.

[0063] The second optical layer 142 may cover the second region 172 and the third region 173 of the second electrode 170, such that the third region 173 lies between the second optical layer 142 and the first optical layer 141. The top surface of the second optical layer 142 and a top surface of the first region 171 of the second electrode 170 may form the same plane. In other words, the top surface of the second optical layer 142 and the top surface of the first region 171 of the second electrode 170 may be at the same level or height or aligned with each other. For example, the first optical layer 141 and the second optical layer 142 may function as a planarization layer.Since there is no step on a surface on which a black matrix 190 is formed, a pattern of the black matrix 190 can be easily formed on the first optical layer 141 and the second optical layer 142. However, the present disclosure is not necessarily limited thereto, and the upper surfaces of the second optical layer 142 and the second electrode 170 may have different heights.

[0064] The black matrix 190 may be an organic insulating material to which a black pigment is added. The second electrode 170 may be in contact with the contact electrode 163 beneath the black matrix 190. A transmission hole 191 may be formed between the structures of the black matrix 190, through which the light emitted by the light-emitting elements 10 escapes. The black matrix 190 may improve the problem of mixing of light emitted by adjacent light-emitting elements 10 by the first optical layer 141.

[0065] A cover layer 180 may be an organic insulating material covering the black matrix 190 and the second electrode 170. In Fig. 3, the configurations of the black matrix 190 and the cover layer 180 are omitted.

[0066] The contact electrode 163 is electrically connected to a first connection line RT1 located at a lower portion, and the first connection line RT1 may be connected to the pixel drive circuit 20. Accordingly, the cathode voltage may be applied to the second electrode 170 via the contact electrode 163. The first electrode 161 may be electrically connected to a second connection line RT2. This will be described further below.

[0067] With reference to Fig. 5, the contact electrode 163 and the signal lines TL1 to TL6 may be arranged on the same plane. The pixel drive circuit 20 may be arranged below the contact electrode 163 and the signal lines TL1 to TL6. If the pixel drive circuit 20 is a pixel driver, a plurality of pixel drivers may be arranged in the display panel.

[0068] A passivation layer 133 may expose the contact electrode 163 so that the contact electrode 163 and the second electrode 170 can be electrically connected. Furthermore, the passivation layer 133 may insulate the signal lines TL2 to TL5 and the second electrode 170.

[0069] With reference to Fig. 6, the connecting part 161a of the first electrode 161 may extend to a side surface 131 of the bank structure 130 and be electrically connected to the connecting line RT2 arranged on the insulating layer 122.

[0070] The first electrode 161, the connecting portion 161a, the signal lines TL, and / or the connecting lines RT1 and RT2 may include a single layer or a multilayer metal layer selected from titanium (Ti), molybdenum (Mo), and aluminum (Al). The first electrode 161, the connecting portion 161a, the signal lines TL, and / or the connecting lines RT1 and RT2 may be formed in a multilayer structure including a first layer ML1, a second layer ML2, a third layer ML3, and a fourth layer ML4, wherein more or fewer layers may be included in the multilayer structure.

[0071] The first layer ML1 and the third layer ML3 may contain titanium (Ti) or molybdenum (Mo). The second layer ML2 may contain aluminum (Al). The fourth layer ML4 may contain a transparent conductive oxide layer such as indium tin oxide (ITO) or indium zinc oxide (IZO), which exhibits excellent adhesion to the solder structure 162 and is corrosion and acid resistant.

[0072] The first layer ML1, the second layer ML2, the third layer ML3 and the fourth layer ML4 can be deposited sequentially and then patterned by a photolithographic process and an etching process.

[0073] The passivation layer 133 may be disposed on the first electrode 161 and the signal line TL and may include an opening hole 133a exposing the solder structure 162.

[0074] The light-emitting element 10 may include a first conductivity-type semiconductor layer 10-1, an active layer 10-2 disposed on the first conductivity-type semiconductor layer 10-1, and a second conductivity-type semiconductor layer 10-3 disposed on the active layer 10-2. A first drive electrode 15 may be disposed under the first conductivity-type semiconductor layer 10-1, and a second drive electrode 14 may be disposed on the second conductivity-type semiconductor layer 10-3.

[0075] The light-emitting element 10 can be formed on a silicon wafer by a method such as metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), sputtering, or the like.

[0076] The first-conductivity-type semiconductor layer 10-1 may be made of a group III-V, group II-VI, or the like compound semiconductor and doped with a first dopant. The first-conductivity-type semiconductor layer 10-1 may be formed of any of the semiconductor materials having a composition formula of Al x1 In y1 Ga (1-x1-y1) N (0<=x1<=1, 0<=y1<=1, and 0<=x1+y1<=1), InAlGaN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP, but not limited to these. If the first dopant is an n-type dopant such as Si, Ge, Sn, Se, Te, or the like, the first conductivity-type semiconductor layer 10-1 may be an n-type nitride semiconductor layer. However, if the first dopant is a p-type dopant, the first conductivity-type semiconductor layer 10-1 may be a p-type nitride semiconductor layer.

[0077] The active layer 10-2 is a layer where electrons (or holes) injected through the first-conductivity-type semiconductor layer 10-1 and holes (or electrons) injected through the second-conductivity-type semiconductor layer 10-3 meet. When the electrons and holes recombine in the active layer 10-2, the electrons transition to a low energy level, and light with a corresponding wavelength can be generated.

[0078] The active layer 10-2 can have a single-well structure, a multi-well structure, a single quantum well structure, a multi-quantum well (MQW) structure, a quantum dot structure, and a quantum line structure, but the structure of the active layer 10-2 is not limited to these. The active layer 10-2 can generate light in the visible light wavelength range. For example, the active layer 10-2 can output light in any of the blue, green, and red wavelength ranges.

[0079] The second-conductivity-type semiconductor layer 10-3 may be disposed on the active layer 10-2. The second-conductivity-type semiconductor layer 10-3 may be made of a group III-V, group II-VI, or the like compound semiconductor and may be doped with a second dopant. The second-conductivity-type semiconductor layer 10-3 may be formed from any form consisting of semiconductor materials having a composition formula of In x2 Al y2 Ga 1-x2-y2N (0<=x2<=1, 0<=y2<=1, and 0<=x2+y2<=1), AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, Ba, or the like, the second conductivity-type semiconductor layer 10-3 may be a p-type semiconductor layer. However, when the second dopant is an n-type dopant, the second conductivity-type semiconductor layer 10-3 may be an n-type nitride semiconductor layer.

[0080] A reflective layer 16 may be disposed on the side surfaces and the bottom of the light-emitting element 10. The reflective layer 16 may have a structure in which a reflective material is dispersed in a resin layer, but is not necessarily limited thereto. For example, the reflective layer 16 can be fabricated as a reflector in various structures. Since the light emitted from the active layer 10-2 is reflected upward by the reflective layer 16, the light extraction efficiency can be increased.

[0081] Although a vertical structure in which the drive electrodes 14 and 15 are arranged on and below a light-emitting structure is described, the present disclosure is not limited to this, and the light-emitting element in the embodiment may also have a lateral structure or a flip-chip structure in addition to the vertical structure. Therefore, the drive electrodes 14 and 15 may also be arranged on the same side of the light-emitting structure when the light-emitting element is implemented with the latter structure.

[0082] With reference to Fig. 7, a main light-emitting element 12a and a sub-pixel light-emitting element 12b may be arranged on the bank structure 130. The second light-emitting element 12 is described here as an example. A 1-1 electrode 161-1 connected to the main light-emitting element 12a extends to one side surface of the bank structure 130 and is electrically connected to a 2-1 connection line RT21 located in a lower part. A 1-2 electrode 161-2 connected to the subordinate light-emitting element 12b may extend to the other side surface of the bank structure 130 to be electrically connected to a 2-2 connection line RT22 located in a lower part.

[0083] The pixel drive circuit 20 can apply an anode voltage to the main light-emitting element 12a via the 2-1 connection line RT21 and an anode voltage to the sub-light-emitting element 12b via the 2-2 connection line RT22. The pixel drive circuit 20 can apply a cathode voltage to the main light-emitting element 12a and the sub-light-emitting element 12b via the first connection line RT1 and the second electrode 170.

[0084] The pixel control circuit 20 can control the luminance by driving the main light-emitting element 12a without driving the sub-light-emitting element 12b, or it can control the luminance by simultaneously driving the main light-emitting element 12a and the sub-light-emitting element 12b. When the main light-emitting element 12a is dimmed, the luminance can be controlled by driving only the sub-light-emitting element 12b.

[0085] Fig. 8 is a view illustrating a display device according to another embodiment of the present specification. Fig. 9 is a cross-sectional view along the line IV-IV' in Fig. 8 according to one embodiment. Fig. 10 is a view illustrating a state in which stress is concentrated in a second electrode disposed in a through hole according to an embodiment.

[0086] With reference to Fig. 8 and Fig. 9, a second electrode 170 may be electrically connected to a contact electrode 163 through a contact hole TH1 formed in a second optical layer 142. The second optical layer 142 may include the contact hole TH1 exposing the contact electrode 163. The second electrode 170 may be inserted into the contact hole TH1 of the second optical layer 142 and come into contact with an upper surface of the contact electrode 163. The contact hole TH1 may be formed in an outer region of a pixel.

[0087] With reference to Fig. 10, since the thickness of the second electrode 170 is relatively thin and the contact hole TH1 is formed deeper than the thickness of the second electrode 170, a stress concentration region BP1 may be generated in a portion 170a of the second electrode 170 formed on a side surface part of the contact hole TH1. Accordingly, there is a risk of cracks being generated in the portion 170a of the second electrode 170 formed around the contact hole TH1.

[0088] However, if the second electrode 170 is connected to the contact electrode 163 in a state of uniform expansion, instead of forming the contact hole TH1 as previously described in Fig. 4, excessive stresses can be prevented or reduced from being applied to the second electrode 170. Accordingly, the occurrence of cracks in the second electrode can be prevented or reduced.

[0089] Fig. 11 is a first modified example of Fig. 8 according to one embodiment. Fig. 12 is a second modified example of Fig. 8 according to one embodiment.

[0090] With reference to Fig. 11, a separate through-electrode 164 can be inserted into the contact hole TH1. The through-electrode 164 is conductive. The through-electrode 164 can contain various conductive materials that can be filled into the contact hole TH1. Since the second electrode 170 is arranged on the through-electrode 164 and thus formed relatively uniformly, the occurrence of excessive stresses can be prevented or reduced.

[0091] With reference to Fig. 12, the through electrode 164 may not completely fill the contact hole TH1, but may partially fill it to a certain height. According to this structure, the depth to which the second electrode 170 is inserted into the contact hole TH1 can be relatively shallow. Since a step of the second electrode 170 can be reduced, the likelihood of cracks occurring can be reduced accordingly.

[0092] Fig. 13A to 13F are views illustrating a method of manufacturing a display device according to an embodiment of the present specification.

[0093] With reference to Fig. 13A, a pixel drive circuit 20 may be formed on a substrate 110, and a buffer layer 121 may be formed on the pixel drive circuit 20. The pixel drive circuit 20 may receive a drive voltage, an image signal (a digital signal), a synchronization signal synchronized with the image signal, and the like, and output an anode voltage and a cathode voltage of a light-emitting element 10 to drive a plurality of pixels. The pixel drive circuit 20 may be arranged in a non-display area NA or below a display area AA.

[0094] Next, the interconnection lines RT1 and RT2 may be formed on the buffer layer 121, and then an insulating layer 122 may be formed. The interconnection lines RT1 and RT2 may be electrically connected to the pixel drive circuit 20 via the buffer layer 121. To drive each pixel, the number of interconnection lines RT1 and RT2 and the number of stacks may be varied in various ways. Accordingly, the stacking number of the interconnection lines RT1 and RT2 and the insulating layer 122 may be two or more layers.

[0095] A bank structure 130 may be formed on the insulating layer 122 to select a position where the light-emitting elements 10 are transferred. The bank structure 130 may include, but is not limited to, an organic insulating material, such as photosensitive photoacrylic or photosensitive polyimide. The bank structure 130 may specify a position where the light-emitting elements 10 are attached during a transfer process of the light-emitting elements 10. However, the bank structure 130 may also be omitted.

[0096] An electrode material may be applied to the insulating layer 122 and the bank structure 130 and then patterned to form a plurality of first electrodes 161 and a contact electrode 163. The plurality of first electrodes 161 are regions where the light-emitting elements 10 are arranged, and the contact electrode 163 is a region to which the second electrodes 170 are electrically connected. A passivation layer 133 may then be formed in the remaining electrode region, excluding the regions where the plurality of first electrodes 161 and the contact electrode 163 are formed.

[0097] A solder structure 162 may be disposed on the first electrode 161. The solder structure 162 may contain, but is not limited to, indium (In), tin (Sn), or an alloy thereof.

[0098] With reference to Fig. 13B, each of the plurality of light-emitting elements 10 may be mounted on the solder structure 162. A pixel may include light-emitting elements 10 in three colors. A first light-emitting element may be a red light-emitting element, a second light-emitting element may be a green light-emitting element, and a third light-emitting element may be a blue light-emitting element. Two light-emitting elements may be mounted in each sub-pixel.

[0099] The transfer method is not particularly limited. For example, the light-emitting elements 10 grown on a semiconductor growth substrate can be transferred primarily to a transfer substrate and then secondarily to a panel substrate, or the light-emitting elements 10 grown on the semiconductor growth substrate can be transferred directly to the panel substrate.

[0100] With reference to Fig. 13C and Fig. 13D, a first optical layer 141 may be formed entirely on the substrate 110 and then patterned so that the upper surfaces of the light-emitting elements 10 and the contact electrode 163 may be exposed. The remaining part of the first optical layer 141, except for a region sufficient to cover the light-emitting elements 10 and the bank structure 130, may be removed. Accordingly, the first optical layer 141 may cover a space between the plurality of light-emitting elements 10 and a space between the plurality of bank structures 130. In this case, the upper surfaces of the light-emitting elements 10 may be exposed at an upper part of the first optical layer 141.

[0101] The first optical layer 141 may contain an organic insulating material in which fine metal particles, such as titanium dioxide particles, are dispersed. The light emitted by the light-emitting elements 10 may be scattered and emitted by the fine metal particles dispersed in the first optical layer 141.

[0102] With reference to Fig. 13E, the second electrode 170 may be arranged on the plurality of light-emitting elements 10. The second electrode 170 may be connected to a plurality of common pixels. The second electrode 170 may be a thin metal electrode that transmits light. The second electrode 170 may be made of a transparent electrode material, such as, but not necessarily limited to, indium tin oxide (ITO).

[0103] The second electrode 170 can be divided to be arranged in each row by patterning. A plurality of divided second electrodes 170 can be electrically connected to the contact electrode 163.

[0104] With reference to Fig. 13F, a second optical layer 142 may be formed surrounding the first optical layer 141. In this process, the second optical layer 142 may cover a portion where the second electrode 170 is connected to the contact electrode 163.

[0105] The second optical layer 142 may be disposed on the insulating layer 122 together with the first optical layer 141. The first optical layer 141 and the second optical layer 142 may contain the same material (e.g., siloxane). For example, the first optical layer 141 may be made of siloxane containing titanium oxide (TiO x), and the second optical layer 142 may be made of siloxane that does not contain titanium oxide (TiO x ).

[0106] Thereafter, a black matrix 190 may be formed on the second electrode 170 and the second optical layer 142, and a cap layer 180 may be formed on the black matrix 190.

[0107] The display device according to the present description can be applied to a mobile device, a video phone, a smart watch, a watch phone, a wearable device, a foldable device, a rollable device, a bendable device, a flexible device, a curved device, a sliding device, a variable device, an electronic notebook, an electronic book, a portable multimedia player (PMP), a personal digital assistant (PDA), an MP3 player, a mobile medical device, a desktop personal computer (PC), a laptop PC, a netbook computer, a workstation, a navigation device, a vehicle display device, a theater display device, a television, a wallpaper device, a signage device, a game device, a notebook, a monitor, a camera, a camcorder, a household appliance, and the like.Furthermore, the display device according to one or more embodiments of the present description can be applied to an organic light-emitting lighting device or an inorganic light-emitting lighting device.

[0108] The display device according to one or more embodiments of the present description may be described as follows.

[0109] A display device according to one or more embodiments of the present description includes: a plurality of first electrodes and a contact electrode arranged on a substrate; a plurality of light-emitting elements arranged above the contact electrode; a first optical layer arranged between the plurality of light-emitting elements; and a second electrode arranged on the first optical layer, wherein the plurality of light-emitting elements are electrically connected between the plurality of first electrodes and the second electrode, wherein the second electrode includes a first region arranged on the first optical layer and a second region extending to the outside of the first optical layer and electrically connected to the contact electrode.

[0110] The second region of the second electrode may be formed uniformly so that the second region of the second electrode is electrically connected to the contact electrode in a flat shape

[0111] The display device may further include a second optical layer configured to cover the second region of the second electrode.

[0112] An upper surface of the second optical layer and an upper surface of the first region of the second electrode may form the same plane.

[0113] The first optical layer and the second optical layer can be made of different materials.

[0114] The first optical layer may contain light-scattering particles.

[0115] The display device may further include a plurality of bank structures arranged below the plurality of light-emitting elements, e.g., between the substrate and the plurality of first electrodes, wherein the plurality of first electrodes are arranged on an upper surface of the plurality of structures.

[0116] The display device may further include a plurality of signal lines extending between the plurality of bank structures and connected to the plurality of first electrodes.

[0117] The contact electrode may be arranged between the plurality of lines.

[0118] The display device may further include a passivation layer disposed on the contact electrode and the plurality of signal lines and exposing the contact electrode so that the contact electrode and the second electrode are electrically connected.

[0119] A plurality of second electrodes may be arranged to be spaced apart from each other for each pixel row, and the plurality of second electrodes may be electrically connected to the contact electrode.

[0120] The second electrode may include a third region configured to extend toward a side surface of the first optical layer and connect the first region to the second region.

[0121] The display device may further include: an insulating layer disposed on the substrate; a plurality of connecting lines connected between the substrate and the insulating layer; and a pixel driving circuit connected to the plurality of connecting lines, wherein the plurality of connecting lines may be electrically connected to the plurality of first electrodes and the contact electrode, respectively.

[0122] The majority of light-emitting elements may consist of inorganic light-emitting diodes.

[0123] The pixel control circuit may be a pixel driver.

[0124] The display device may further include: a second optical layer located between the second region of the second electrode and the contact electrode; and a through electrode at least partially filling a contact hole of the second optical layer to electrically connect the second region of the second electrode to the contact electrode.

[0125] The through electrode can completely fill the contact hole.

[0126] A display device according to one or more embodiments of the present description includes: a plurality of light-emitting elements arranged on the substrate and respectively connected to a plurality of first electrodes; a first optical layer arranged between the plurality of light-emitting elements; a second electrode arranged on the first optical layer; and a second optical layer surrounding the first optical layer, wherein the plurality of light-emitting elements are electrically connected between the plurality of first electrodes and the second electrode, wherein the second electrode includes a first region arranged on the first optical layer and a second region extending to the outside of the first optical layer, and the second optical layer is arranged on the second region of the second electrode.

[0127] The first optical layer and the second optical layer can be made of different materials.

[0128] The first optical layer may contain light-scattering particles.

[0129] The display device may further include a plurality of bank structures arranged under the plurality of light-emitting elements.

[0130] The display device may further include a plurality of signal lines extending between the plurality of bank structures and connected to the plurality of first electrodes.

[0131] The display device may include a contact electrode disposed on the substrate and electrically connected to the second electrode, wherein the contact electrode may be disposed between the plurality of signal lines.

[0132] A plurality of second electrodes may be arranged to be spaced apart from each other for each pixel row, and the plurality of second electrodes may be electrically connected to the contact electrode.

[0133] The display device may further include: an insulating layer disposed on the substrate; a plurality of connecting lines connected between the substrate and the insulating layer; and a pixel driving circuit connected to the plurality of connecting lines, wherein the plurality of connecting lines may be electrically connected to the plurality of first electrodes and the contact electrode, respectively.

[0134] According to the present invention, the occurrence of cracks in a cathode electrode can be prevented or reduced. Accordingly, low-power driving can be performed because the increase in the resistance of the cathode electrode is improved.

[0135] The effects of the present description are not limited to the above-mentioned effects, and other effects not mentioned will be clearly apparent to those skilled in the art from the description of the claims.

[0136] Since the content of the description, which is described in the problem to be solved, the means for solving the problem and the effects described above, does not specify the essential features of the claims, the scope of the claims is not limited by the points described in the content of the description.

[0137] Although the embodiments have been described in detail with reference to the accompanying drawings, the present disclosure is not necessarily limited to these embodiments and can be modified in various ways without departing from the technical concepts of the present disclosure. Accordingly, the embodiments disclosed in the present disclosure are not intended to limit the technical concepts of the present disclosure, but to describe the technical concepts of the present disclosure, and the scope of the technical concepts of the present disclosure is not limited by these embodiments. Accordingly, the embodiments described above should be understood in all respects as illustrative and not restrictive. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] KR 10-2023-0090571

[0001]

Claims

[1] A display device (100) comprising: a substrate (110); a plurality of first electrodes (161) on the substrate (110); a contact electrode (163) on the substrate (110); a plurality of light-emitting elements (10) on the plurality of first electrodes (161); a first optical layer (141) between the plurality of light-emitting elements (10); and a second electrode (170) on the plurality of light-emitting elements (10), the second electrode (170) including a first region (171) located on the plurality of light-emitting elements (10) and a second region (172) extending over the outside of the first optical layer (141) and in contact with the contact electrode (163). [2] The display device (100) according to claim 1, further comprising: a second optical layer (142) covering the second region (172) of the second electrode (170). [3] The display device (100) of claim 2, wherein the first optical layer (141) includes a first material and the second optical layer (142) includes a second material different from the first material. [4] The display device (100) of claim 3, wherein the first optical layer (141) contains light-scattering particles. [5] The display device (100) according to any one of claims 1 to 4, further comprising: a plurality of bank structures (130) between the substrate (110) and the plurality of first electrodes (161), wherein the plurality of first electrodes (161) are arranged on an upper surface of the plurality of bank structures (130). [6] The display device (100) according to claim 5, further comprising: a plurality of signal lines (TL1-TL6) extending between the plurality of bank structures (130), the plurality of signal lines (TL1-TL6) being connected to the plurality of first electrodes (161). [7] The display device (100) according to claim 6, wherein the contact electrode (163) is located between the plurality of signal lines (TL1-TL6). [8] The display device (100) according to any one of claims 1 to 7, further comprising: a plurality of second electrodes (170) including the second electrode (170), wherein the plurality of second electrodes (170) are arranged over a plurality of pixel rows and each of the plurality of second electrodes (170) is spaced apart from each other for each pixel row of the plurality of pixel rows, wherein the plurality of second electrodes (170) are electrically connected to the contact electrode (163). [9] The display device (100) according to any one of claims 1 to 8, wherein the second electrode (170) includes a third region (173) on a side surface of the first optical layer (141), the third region (173) connecting the first region (171) and the second region (172). [10] The display device (100) according to any one of claims 1 to 9, further comprising: an insulating layer on the substrate (110); a plurality of connecting lines (RT1, RT2) between the substrate (110) and the insulating layer; and a pixel drive circuit (20) connected to the plurality of connecting lines (RT1, RT2), wherein the plurality of connecting lines (RT1, RT2) are electrically connected to the plurality of first electrodes (161) and the contact electrode (163). [11] The display device (100) according to any one of claims 1 to 10, wherein the plurality of light-emitting elements (10) are inorganic light-emitting diodes. [12] The display device (100) according to claim 10 or 11, wherein the pixel driving circuit (20) is a driving circuit. [13] A display device (100) comprising: a substrate (110); a plurality of first electrodes (161) on the substrate (110); a plurality of light-emitting elements (10) on the plurality of first electrodes (161); a first optical layer (141) between the plurality of light-emitting elements (10); a second electrode (170) on the plurality of light-emitting elements (10), the second electrode (170) including a first region (171) located on the plurality of light-emitting elements (10) and a second region (172) extending outside the first optical layer (141); and a second optical layer (142) surrounding the first optical layer (141), the second optical layer (142) being located on the second region (172) of the second electrode (170). [14] The display device (100) of claim 13, wherein the first optical layer (141) includes a first material and the second optical layer (142) includes a second material different from the first material. [15] The display device (100) of claim 14, wherein the first optical layer (141) contains light-scattering particles. [16] The display device (100) according to any one of claims 13 to 15, further comprising: a plurality of bank structures (130) between the substrate (110) and the plurality of first electrodes (161), wherein the plurality of first electrodes (161) are arranged on an upper surface of the plurality of bank structures (130). [17] The display device (100) of claim 16, further comprising: a plurality of signal lines (TL1-TL6) extending between the plurality of bank structures (130), the plurality of signal lines (TL1-TL6) being connected to the plurality of first electrodes (161). [18] The display device (100) of claim 17, further comprising: a contact electrode (163) on the substrate (110) and between the plurality of signal lines (TL1-TL6), wherein the contact electrode (163) is connected to the second electrode (170). [19] The display device (100) of claim 18, further comprising: a plurality of second electrodes (170) including the second electrode (170), wherein the plurality of second electrodes (170) are arranged over a plurality of pixel rows and each of the plurality of second electrodes (170) is spaced apart from each other for each pixel row of the plurality of pixel rows, wherein the plurality of second electrodes (170) are electrically connected to the contact electrode (163). [20] The display device (100) according to claim 18 or 19, further comprising: an insulating layer on the substrate (110); a plurality of connecting lines (RT1, RT2) between the substrate (110) and the insulating layer; and a pixel drive circuit (20) connected to the plurality of connecting lines (RT1, RT2), wherein the plurality of connecting lines (RT1, RT2) are electrically connected to the plurality of first electrodes (161) and the contact electrode (163).

Images