INDICATOR DEVICE AND METHOD FOR MANUFACTURING AN INDICATOR DEVICE

Abstract

A display device (10) and a method for manufacturing the display device (10) are disclosed. The display device (10) comprises a display panel on which a plurality of sub-pixels and lines connected to the sub-pixels are arranged, as well as a control circuit configured to control the sub-pixels. The display panel further comprises a plurality of protruding bank structures (130) arranged in the sub-pixels and a light-emitting element (100, 300) arranged in each of the bank structures (130). The light-emitting element (100, 300) comprises a first electrode (161), a second electrode (170), a light-emitting layer (100a, 300a) arranged between the first electrode (161) and the second electrode (170), and a reflector (16, 36) covering side surfaces of the light-emitting layer (100a, 300a) and at least part of the side surfaces of the first electrode (161).The reflector (16, 36) contains a first insulating layer (216, 316), a second insulating layer (220, 320) and a metal layer (218, 318) arranged between the first insulating layer (216, 316) and the second insulating layer (220, 320).

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Korean Patent Application No. 2023-0104258, filed on August 9, 2023. BACKGROUND OF THE INVENTIONField of the invention

[0002] The present disclosure relates to a display device and a method of manufacturing the display device, and more particularly, for example, without limitation, to a display device in which a reflective layer is provided within a light-emitting element to allow light to be directly reflected by the reflective layer in the light-emitting element, and a method of manufacturing the same. Related prior art

[0003] Electroluminescent display devices can be divided into organic light-emitting diode (OLED) display devices, in which OLEDs are arranged in pixels, and inorganic light-emitting display devices (hereinafter referred to as "display devices"), in which inorganic light-emitting diodes (hereinafter referred to as "LEDs") are arranged in pixels.

[0004] Because electroluminescent displays display images using self-luminous elements, they do not require a separate light source, such as a backlight, and can therefore be realized in a variety of thin forms. Because electroluminescent displays have a fast response time, high luminous efficiency and brightness, a wide viewing angle, and can display a perfect black gradation, they have excellent contrast ratios and color gamuts.

[0005] OLED display devices require a design that prevents the penetration of oxygen and moisture because an oxidation phenomenon may occur between an organic light-emitting layer and an electrode due to the penetration of moisture and oxygen.

[0006] An example of a display device is a micro-LED display device, in which micro-LEDs are arranged in pixels, attracting attention as a next-generation display device. A micro-LED can be an inorganic LED with a size of 100 µm or less. Micro-LEDs can be manufactured separately using a semiconductor process, transferred to pixels on a display panel substrate of the display device, and arranged in sub-pixels for each color.

[0007] The description contained in the description of the related art section should not be considered prior art merely because it is mentioned in or associated with the description of the related art section. The description of the related art section may contain information describing one or more aspects of the subject art, and the description in that section does not limit the invention. SUMMARY OF THE INVENTION

[0008] The inventors have recognized that in a process for manufacturing a display device, defects can be continuously caused by a tight tolerance when forming a reflective layer on a bank structure that is a transfer structure of micro light-emitting diodes (LEDs). Therefore, the light efficiency may be compromised if the reflective layer is formed under the micro LED.

[0009] This description aims to solve the needs and / or problems described above.

[0010] The present description also relates to the provision of a display device in which a reflective layer is provided within a light-emitting element to allow light to be directly reflected by the reflective layer in the light-emitting element, thereby increasing brightness efficiency, and a method of manufacturing the display device.

[0011] The objects of the present disclosure are not limited to the objects described above, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

[0012] A display device according to one or more exemplary embodiments of the present description may include a display panel on which a plurality of subpixels and lines connected to the subpixels are arranged, and a pixel driving circuit configured to drive the subpixels, wherein the display panel further includes a plurality of protruding bank structures arranged in the subpixels and a light-emitting element arranged in each of the bank structures, the light-emitting element includes a first electrode, a second electrode, a light-emitting layer arranged between the first electrode and the second electrode, and a reflector covering side surfaces of the light-emitting layer and at least a part of the side surfaces of the first electrode, and the reflector includes a first insulating layer,a second insulating layer and a metal layer arranged between the first insulating layer and the second insulating layer.,

[0013] A method for manufacturing a display device may include forming a display panel on which a plurality of subpixels and lines connected to the subpixels are arranged, and forming a pixel drive circuit configured to drive the subpixels, wherein forming the display panel further includes forming a plurality of protruding bank structures arranged in the subpixels and forming a light-emitting element arranged in each of the bank structures, wherein forming the light-emitting element includes forming a first electrode and a second electrode, forming a light-emitting layer arranged between the first electrode and the second electrode, and forming a reflector covering the side surfaces of the light-emitting layer and at least a part of the side surfaces of the first electrode.and forming the reflector includes forming a first insulating layer and a second insulating layer on the side surfaces of the light-emitting element and forming a metal layer between the first insulating layer and the second insulating layer.

[0014] In the present disclosure, a reflective layer may be formed in the light-emitting element so that light can be directly reflected within the light-emitting element, thereby increasing the light-emitting efficiency. Specifically, an exemplary embodiment of the present disclosure may increase the internal light-emitting efficiency of the light-emitting element by disposing the reflective layer inside the light-emitting element, thereby increasing the light-emitting efficiency even at low power consumption, thereby improving yield.

[0015] Since in the present disclosure, the process of forming a reflecting mirror on the upper part of the bench structure can be omitted, the process can be simplified, and the process tolerance errors can be fundamentally improved.

[0016] The present invention can increase light emission efficiency by disposing a reflective layer within a light-emitting element, thereby reducing process materials because a sidewall diffuser made of an expensive material with excellent light emission efficiency is not required.

[0017] Furthermore, an exemplary embodiment of the disclosure may simplify the manufacturing process by omitting a patterning process for forming a reflective layer under the light-emitting element to form a reflective mirror.

[0018] Furthermore, an exemplary embodiment of the disclosure may reduce the cost of the manufacturing process by incorporating a reflective layer into the light-emitting element to increase the efficiency of light emission without using an expensive sidewall diffuser material.

[0019] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a view showing a display device according to an exemplary embodiment of the present disclosure. Fig. 2 is an enlarged view of area A in Fig. 1. Fig. 3 is a view showing a partial area of ​​a pixel. Fig. 4 is a cross-sectional view taken along line II' in Fig. 3. Fig. 5 is a cross-sectional view along the line II-II' in Fig. 3. Fig. 6 is a cross-sectional view taken along the line III-III' in Fig. 3. Fig. 7 is a cross-sectional view showing an example in which a main light-emitting element and a sub-light-emitting pixel are electrically connected to a pixel driving circuit. Fig. 8 is a view showing a display device according to another exemplary embodiment of the present disclosure. Fig. 9 is a cross-sectional view along the line IV-IV' in Fig. 8. Fig. 10 is a cross-sectional view showing a longitudinal sectional structure of a part of the display device taken along the line II' in Fig. 1, which is an enlarged cross-sectional view of “B” in Fig. 4 is. Fig. 11 is a cross-sectional view showing a longitudinal sectional structure of a part of the display device taken along the line II' in Fig. 1, which is an enlarged cross-sectional view of “C” in Fig. 4 is. Fig. 12 is a plan view showing a light-emitting element of the display device according to an exemplary embodiment of the present specification. Fig. 13 is a cross-sectional view showing a longitudinal sectional structure of a part of the light-emitting element taken along the line VV' in Fig. 12 shows. Fig. 14A to 14T are cross-sectional views showing a process for manufacturing the light-emitting element of the display device according to an exemplary embodiment of the present specification. Fig. 15 is a plan view showing a light-emitting element of the display device according to another exemplary embodiment of the present specification. Fig. 16 is a cross-sectional view showing a longitudinal sectional structure of a part of the light-emitting element taken along the line VI-VI' in Fig. 15 shows. Fig. 17A to 17T are cross-sectional views showing a process for manufacturing the light-emitting element of the display device according to another exemplary embodiment of the present specification. Fig. 18A to 18G are process cross-sectional views for describing a process for manufacturing a pixel including the light-emitting element of the display device according to an exemplary embodiment of the present specification. Fig. 19 is a cross-sectional view schematically showing a state in which light is reflected in and emitted from the light-emitting element of the display device according to an exemplary embodiment of the present specification. Fig. 20 is a cross-sectional view schematically showing a state in which light is reflected in and emitted from the light-emitting element of the display device according to another exemplary embodiment of the present specification.

[0021] 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 OF THE EXEMPLARY EMBODIMENTS

[0022] Advantages and features of exemplary embodiments of the present description and methods for implementing them will become apparent by reference to exemplary embodiments described in detail below in conjunction with the accompanying drawings. The present disclosure is not limited to the embodiments disclosed below, but may be embodied in various different forms. These exemplary embodiments are provided merely to make the disclosure of the present disclosure complete and to fully inform those skilled in the art to which the present disclosure refers of the scope of the present disclosure, and the present disclosure is defined only by the scope of the appended claims.

[0023] Since the shapes, sizes, dimensions (e.g., length, width, height, thickness, radius, diameter, area, etc.), ratios, angles, numbers, and the like illustrated in the drawings for describing exemplary embodiments of the present disclosure are not limited to the illustrated items, the present disclosure is not limited to them. The same reference numeral indicates the same components throughout the specification. When describing the present disclosure, if it is determined that the detailed description of a related known technology might unnecessarily obscure the gist of the present disclosure, the detailed description of that technology will be omitted.

[0024] When the terms "comprise," "have," "comprise," "contain," "form," "are," and "consist of" are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it may be understood as a plurality of components, unless expressly stated otherwise.

[0025] A dimension including a size and thickness of each component illustrated in the drawing is illustrated for convenience of description, and the present disclosure is not limited to the size and thickness of the illustrated components, but it should be noted that the relative dimensions, including the relative size, location, and thickness of the components illustrated in various drawings, are part of the present disclosure.

[0026] When designing a component, it is assumed that the component includes fault tolerance, even if there is no separate explicit description.

[0027] When describing the positional relationship and connection between two components, such as "on", "over", "above", "under", "next to", "below", "beside", "under", "near", "close to", "adjacent to", "on either side of", "adjacent to", "connected or coupled", "crossing or intersecting" or the like, one or more other components may be arranged between the components, unless the term "immediate" or "direct" is described.

[0028] Spatially relative terms such as "beneath," "beneath," "under," "beneath," "above," "above," and the like may be used herein for ease of description to describe the relationship of one element or feature to another element or feature, as illustrated in the figures. It should be understood that the spatially relative terms may encompass, in addition to the orientation illustrated in the figures, different orientations of an element in use or operation. For example, if an element is flipped in the figures, elements described as being "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" may encompass both a below and above orientation. Similarly, the exemplary term "above" or "above" may encompass both an above and below orientation.

[0029] When the temporal connection is described using the terms “after”, “subsequently”, “following”, “then”, “before” or similar, it may contain a non-consecutive case unless the term “immediate” or “direct” is used.

[0030] To distinguish components, the component names may be prefixed with "first," "second," and the like, but their functions or structures are not limited by the ordinal numbers or component names. To simplify description, the ordinal numbers of the names of the same components may be different in different embodiments.

[0031] Furthermore, terms such as "first," "second," "A," "B," "(a)," "(b)," or similar terms may be used herein when describing components of the present disclosure. Each of these terms is not used to define a nature, order, or sequence of a corresponding component, but merely to distinguish the corresponding component from other components. When a particular structural element or layer is described as being "connected," "coupled," "glued," or "joined" to another structural element or layer, this is generally interpreted to mean that another structural element or layer may be directly or indirectly "connected," "coupled," "glued," or "joined" to the structural element or layer.

[0032] It should be understood that the term "at least one" includes all combinations associated with any one element. For example, "at least one of a first element, a second element, and a third element" can include all combinations of two or more elements selected from the first, second, and third elements, as well as any element of the first, second, and third elements.

[0033] The term "device" used herein may refer to a display device including a display panel and a driver for driving the display panel. Examples of the display device may include a light-emitting element and the like. Furthermore, examples of the device may include a notebook computer, a television, a computer monitor, an automotive device, a wearable device, and an automotive equipment device, as well as a configured electronic device (or device) or a configured device (or device), e.g., a mobile electronic device such as a smartphone or an electronic pad, which are complete products or finished products including a light-emitting element and the like, but the embodiments of the present disclosure are not limited thereto.

[0034] Like reference numerals generally refer to like elements throughout the specification.

[0035] A size and a thickness of each component illustrated in the drawing are illustrated for convenience, and the present disclosure is not limited to the size and thickness of the illustrated component.

[0036] The following exemplary embodiments may be partially or fully coupled or combined, allowing for various technological interactions and control. The exemplary embodiments may be implemented independently of one another and jointly in the associated relationship.

[0037] 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 example 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.

[0038] Hereinafter, various exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0039] Fig. 1 is a view of a display device according to an exemplary embodiment of the present disclosure. Fig. 2 is an enlarged view of area A in Fig. 1. Fig. 3 is a view showing a partial area of ​​a pixel.

[0040] With reference to Fig. 1 and Fig. 2, a display device 10 according to the exemplary embodiment of the present disclosure includes a display panel that visually displays input images. The display panel may include a display area AA in which images are displayed, and a non-display area NA in which the images are not displayed. The non-display area NA is configured to be located near the display area AA and to partially or completely surround the display area AA. Various wiring and drive circuits, as well as a pad part PAD to which integrated circuits, printed circuits, and the like are connected, may be installed in the non-display area NA.

[0041] A plurality of light-emitting elements 100 arranged in the display area AA to form pixels PXLs may be micro-sized inorganic light-emitting elements. The inorganic light-emitting element may be grown on a silicon wafer and then attached to the display panel through a transfer process.

[0042] The transfer process of the light-emitting element 100 can be performed for each previously designated area. Although Fig. 1 shows that the display area AA is divided into nine transfer areas ST, but the size or number of divisions of the transfer areas is not limited thereto. The transfer process can be performed sequentially or simultaneously for the first to ninth transfer areas ST. The blue light-emitting element 100, the green light-emitting element 100, and the red light-emitting element 100 can each be transferred sequentially into the transfer areas ST. Alternatively, the display area AA is divided into sixteen transfer areas ST, and the transfer process can be performed sequentially or simultaneously on the first to sixteenth transfer areas ST. The blue light-emitting element, the green light-emitting element, the red light-emitting element, and the white light-emitting element can each be transferred sequentially into the transfer areas ST.

[0043] A data drive circuit or a gate drive circuit may be arranged in the non-display area NA, and lines may be provided through which control signals for controlling the drive circuits are supplied. Here, the control signals may include various timing signals, including a clock signal, an input data enable signal, and synchronization signals, and the control signals may be received via the pad portion PAD.

[0044] The pixels PXLs can be driven by the pixel drive circuit. The pixel drive circuit can drive the plurality of pixels by receiving a drive voltage, image signals (digital signals), synchronization signals synchronized with the image signals, and the like, and outputting anode voltages and a cathode voltage of the light-emitting element 10. 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.

[0045] Each of the pixels PXLs may include a plurality of sub-pixels, each having a different color. The plurality of sub-pixels SPX is a minimum unit that configures the display area, and n sub-pixels SPX constitute one pixel. Each of the plurality of sub-pixels SPX may emit light with mutually different wavelengths. The plurality of sub-pixels may include first to third sub-pixels that emit light of mutually different colors. For example, the plurality of pixels may include a red sub-pixel in which the light-emitting element 100 for emitting light with a red wavelength is arranged, a green sub-pixel in which the light-emitting element 100 for emitting light with a green wavelength is arranged, and a blue sub-pixel in which the light-emitting element 100 for emitting light with a blue wavelength is arranged.The plurality of pixels may further include a white sub-pixel.

[0046] Meanwhile, the plurality of subpixels SPX can be configured in various colors and configurations as needed. However, the present disclosure is not limited thereto. For example, the plurality of subpixels SPX may include red, green, and blue subpixels, wherein the red, green, and blue subpixels may be arranged in a repeated manner. Alternatively, the plurality of subpixels SPX may include red, green, blue, and white subpixels, wherein the red, green, blue, and white subpixels may be arranged in a repeated manner, or the red, green, blue, and white subpixels may be arranged in a quad type. For example, the red subpixel, the blue subpixel, and the green subpixel may be arranged sequentially in a row direction, or the red subpixel, the blue subpixel, the green subpixel, and the white subpixel may be arranged sequentially in the row direction.However, in the embodiment of the present disclosure, the color type, arrangement type, and arrangement order of the sub-pixels are not limitative and can be configured in various forms according to the light emission characteristics, the lifetime of the device, and the descriptions of the device.

[0047] However, the sub-pixels may have different light-emitting areas depending on their light-emitting characteristics. For example, a sub-pixel that emits light of a different color than a blue sub-pixel may have a different light-emitting area than the blue sub-pixel. For example, the red sub-pixel, the blue sub-pixel, and the green sub-pixel, or the red sub-pixel, the blue sub-pixel, the white sub-pixel, and the green sub-pixel may each have a different light-emitting area.

[0048] With reference to Fig. 2 and Fig. 3, the plurality of pixels PXLs may be arranged sequentially in a first direction (X-axis direction) and a second direction (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 sub-pixels may include a first red sub-pixel in which a 1-1 light-emitting element 101a for emitting light with the red wavelength is arranged, a second red sub-pixel in which a 1-2 light-emitting element 101b for emitting light with the red wavelength is arranged, a first green sub-pixel in which a 2-1 light-emitting element 102a for emitting light with the green wavelength is arranged, a second green sub-pixel in which a 2-2 light-emitting element 102b for emitting light with the green wavelength is arranged, a first blue sub-pixel in which a 3-1 light-emitting element 103a for emitting light with the blue wavelength is arranged, and a second blue sub-pixel in which a 3-2 light-emitting element 103b is arranged to emit light having the blue wavelength.The 1-1 light-emitting element 101a, the 2-1 light-emitting element 102a and the 3-1 light-emitting element 103a can be regarded as main light-emitting elements.

[0049] The 1-2 light-emitting element 101b, the 2-2 light-emitting element 102b and the 3-2 light-emitting element 103b can be regarded as light-emitting sub-elements.

[0050] Since a sub-pixel may include one or more light-emitting elements, if one light-emitting element fails, the brightness of the sub-pixel can be adjusted by increasing the brightness of the remaining light-emitting elements. However, the present disclosure is not necessarily limited to this, and a sub-pixel may also include only one light-emitting element.

[0051] A plurality of first electrodes 161 may each be arranged below the light-emitting element 100 and selectively connected to a plurality of signal lines TL1 to TL6 via extensions 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 electrode structures integrated with anodes during an electrode patterning process.

[0052] For example, the first signal line TL1 may be connected to an anode of the first red sub-pixel, and the second signal line TL2 may be connected to an anode of the second red sub-pixel. The third signal line TL3 may be connected to an anode of the first green sub-pixel, and the fourth signal line TL4 may be connected to an anode of the second green sub-pixel. The fifth signal line TL5 may be connected to an anode of the first blue sub-pixel, and the sixth signal line TL6 may be connected to an anode of the second blue sub-pixel. When a sub-pixel contains only one light-emitting element, the number of signal lines TL may be reduced by half. For example, the first signal line TL1 may be connected to an anode of the red sub-pixel, the second signal line TL2 to an anode of the green sub-pixel, and the third signal line TL3 to an anode of the blue sub-pixel, but the present disclosure is not limited thereto.

[0053] The second electrode 170 may be a cathode arranged in each row to apply the cathode voltage to the light-emitting elements 100 arranged one after another in the first direction (X-axis direction). The plurality of second electrodes 170 may be arranged to be spaced apart from each other in the second direction (Y-axis direction). The plurality of second electrodes 170 may be connected to the cathode voltage via contact electrodes 162. The plurality of second electrodes 170 may each be electrically connected to the contact electrode 162. However, the present disclosure is not limited to this, and the second electrode 170 is not divided into a plurality of electrodes and may be formed as one electrode layer serving as a common electrode.

[0054] Fig. 4 is a cross-sectional view taken along line II' in Fig. 3. Fig. 5 is a cross-sectional view along the line II-II' in Fig. 3. Fig. 6 is a cross-sectional view taken along the line III-III' in Fig. 3. Fig. 7 is a cross-sectional view showing an example in which two light-emitting elements are connected to a pixel driving circuit.

[0055] With reference to Fig. 3 to 5, the display device 10 according to the exemplary embodiment includes a plurality of first electrodes 161 and contact electrodes 162 arranged on a substrate 110, a plurality of light-emitting elements 100 arranged on the plurality of first electrodes 161, a first insulating interlayer 141 arranged between the plurality of light-emitting elements 100, and a second electrode 170 arranged on the plurality of light-emitting elements 100.

[0056] The substrate 110 may be made of flexible plastic. For example, the substrate 110 may be made as a single- or multi-layer substrate 110 from a material selected from the group consisting of polyimide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, polyarylate, polysulfone, and a cyclic olefin copolymer. In some example embodiments, the substrate 110 may be made of a flexible polymeric film. For example, the flexible polymeric film may be made of any of the following: polyimide (PI), polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), polyarylate (PAR), polysulfone (PSF), cyclic olefin copolymer (COC), triacetylcellulose (TAC), polyvinyl alcohol (PVA), and polystyrene (PS), but is not limited to these.The substrate 110 may be, for example, a ceramic or glass substrate.

[0057] A pixel drive circuit 20 may be disposed in the display area AA on the substrate 110. The pixel drive circuit 20 may include a plurality of thin-film transistors (TFTs) using a semiconductor material such as an oxide semiconductor, an amorphous semiconductor, or a polycrystalline semiconductor.

[0058] The oxide semiconductor material can have excellent leakage current prevention properties and relatively low manufacturing costs. The oxide semiconductor can be made from a metal oxide such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), and titanium (Ti), or a combination of a metal such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), or titanium (Ti) and its oxide. In particular, the oxide semiconductor may include, but is not limited to, zinc oxide (ZnO), zinc tin oxide (ZTO), zinc indium oxide (ZIO), indium oxide (InO), titanium oxide (TiO), indium gallium zinc oxide (IGZO), indium zinc tin oxide (IZTO), indium zinc oxide (IZO), indium gallium tin oxide (IGTO), and indium gallium oxide (IGO).

[0059] Polycrystalline semiconductor materials feature high movement speeds of charge carriers such as electrons and holes, resulting in high mobility, low energy consumption, and high reliability. Polycrystalline semiconductors can be made from, but are not limited to, polycrystalline silicon (poly-Si).

[0060] The amorphous semiconductor material can be made of amorphous silicon (a-Si), but is not limited to it.

[0061] The pixel drive circuit 20 may include at least one drive TFT, at least one switching TFT, and at least one storage capacitor. If the pixel drive circuit 20 includes a plurality of TFTs, the pixel drive circuit 20 may be formed on the substrate 110 through a TFT manufacturing process. In an exemplary embodiment, the pixel drive circuit 20 may be a concept that collectively indicates the plurality of TFTs electrically connected to the light-emitting element 100.

[0062] Pixel drive circuit 20 may be a drive driver fabricated on single-crystal semiconductor substrate 110 using a metal oxide silicon field-effect transistor (MOSFET) manufacturing process. The drive driver may include a plurality of pixel drive circuits and drive a plurality of sub-pixels. When pixel drive circuit 20 is implemented as a drive driver, the drive driver may be attached to the adhesive layer by the transfer process after an adhesive layer is disposed on substrate 110.

[0063] A buffer layer 121 may be disposed on the substrate 110, covering the pixel drive circuit 20. The buffer layer 121 may be made of an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide.

[0064] The buffer layer 121 may be an inorganic insulating material such as silicon nitride (SiN x) or silicon oxide (SiO2), in such a way that the inorganic insulating material is stacked in multiple layers. For example, the buffer layer 121 may be configured as a single layer or multiple layers of silicon nitride (SiNx) or silicon oxide (SiOx). For example, the buffer layer 121 may be formed by an inorganic film in a single layer or in multiple layers. For example, the inorganic film in a single layer may be a silicon oxide (SiOx) film or a silicon nitride (SiNx) film. Multi-layer inorganic films may be formed by alternately stacking one or more silicon oxide (SiOx) films, one or more silicon nitride (SiNx) films, and one or more amorphous silicon (a-Si) films, but the present disclosure is not limited thereto.For example, the buffer layer 121 may use an organic insulating material and an inorganic insulating material in a manner that the organic insulating material and the inorganic insulating material are stacked in multiple layers.

[0065] An insulating layer 122 may be disposed on the buffer layer 121. The insulating layer 122 may be made of an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide. The connecting lines RT1 and RT2 may be disposed on the buffer layer 121. The connecting lines RT1 and RT2 may be connected to the corresponding signal lines TL1 to TL6 or connected to the signal lines TL1 to TL6. The connecting lines RT1 and RT2 may include a plurality of conductive patterns disposed on different layers with one or more insulating layers interposed therebetween. The conductive patterns disposed on different layers may be electrically connected by vias passing through the insulating layers.

[0066] A plurality of bank structures 130 may be arranged on the insulating layer 122. At least one light-emitting element 100 may be arranged on each bank structure 130. For example, a first light-emitting element 101 may be arranged on the first bank structure 130, a second light-emitting element 102 may be arranged on the second bank structure 130, and a third light-emitting element 103 may be arranged on the third bank structure 130.

[0067] The bank structure 130 may be made of an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide. The bank structure 130 may control the mounting position of the light-emitting element 100 during the transfer process of the light-emitting element 100. The bank structure 130 may also be omitted.

[0068] A solder structure 163 may be disposed on the first electrode 161. The solder structure 163 may be made of, but is not limited to, indium (In), tin (Sn), or an alloy thereof.

[0069] The plurality of light-emitting elements 100 may each be mounted on the solder structure 163. One pixel may include light-emitting elements 100 in three colors. The first light-emitting element 101 may be a red light-emitting element, the second light-emitting element 102 may be a green light-emitting element, and the third light-emitting element 103 may be a blue light-emitting element. Two light-emitting elements may be formed on each sub-pixel. For example, the first light-emitting element 101 may include two red light-emitting elements, the second light-emitting element 102 may include two green light-emitting elements, and the third light-emitting element 103 may include two blue light-emitting elements, but the present disclosure is not limited thereto.

[0070] The first insulating interlayer 141 may cover the plurality of light-emitting elements 100 and the bank structures 130. Therefore, the first insulating interlayer 141 may cover a space between the plurality of light-emitting elements 100 and a space between the bank structures 130. The first insulating interlayers 141 may extend in the first direction X and be spaced apart from each other in the second direction Y to be separated between the rows of pixels.

[0071] The first insulating interlayer 141 may contain an inorganic insulating material or an organic insulating material.

[0072] The second electrode 170 may be arranged on the plurality of light-emitting elements 100. The second electrode 170 may be commonly connected to the plurality of pixels PXLs. The second electrode 170 may be a thin electrode through which light is transmitted. The second electrode 170 may be made of a transparent electrode material, such as, but not necessarily limited to, indium tin oxide (ITO) or indium zinc oxide (IZO).

[0073] The second electrodes 170 may extend in the first direction (X-axis direction) and be spaced apart from each other in the second direction (Y-axis direction). The second electrode 170 may include a first region 171 disposed on an upper surface of the light-emitting element 10 and an upper surface of the first insulating interlayer 141, a second region 172 in contact with the contact electrode 162 and electrically connected to the contact electrode 162, and a third region 173 disposed on side surfaces of the first insulating layer 141 to connect the first region 171 to the second region 172.

[0074] In a plan view, the plurality of second electrodes 170 may each overlap the first insulating interlayer 141, and the second region 172 may cover an outer surface of the first insulating interlayer 141.

[0075] A second insulating interlayer 142 may be an inorganic insulating material layer or an organic insulating material layer surrounding the edge of the first insulating interlayer 141. The second insulating interlayer 142 may be disposed on the insulating layer 122 together with the first insulating interlayer 141. The first insulating interlayer 141 and the second insulating interlayer 142 may be made of the same material, ie, the inorganic insulating material and the organic insulating material, or of different materials. However, the present disclosure is not necessarily limited thereto.

[0076] According to the exemplary embodiment, since the second region 172 of the second electrode 170 is connected to the contact electrode 162 in a state where it is completely flat, stress is not excessively concentrated at a point where the second region 172 is connected to the contact electrode 162. Therefore, it is possible to effectively prevent the occurrence of cracks in the second electrode 170.

[0077] The second insulating interlayer 142 may cover the second region 172 and the third region 173 of the second electrode 170. An upper surface of the second insulating interlayer 142 may be coplanar with an upper surface of the first region 171 of the second electrode 170. In other words, the first insulating interlayer 141 and the second insulating interlayer 142 may serve as planarization layers. Therefore, since there is no step on a surface on which a black matrix 180 is formed, patterns of the black matrix 180 can be easily formed on the first insulating interlayer 141 and the second insulating interlayer 142. However, the present disclosure is not necessarily limited to this, and the upper surface of the second insulating interlayer 142 and the upper surface of the second electrode 170 may be at different heights.

[0078] The black matrix 180 may be made of an organic insulating material to which a black pigment is added. The second electrode 170 may be in contact with the contact electrode 162 under the black matrix 180. A transmission hole 181 may be formed between the structures of the black matrix 180, through which the light emitted by the light-emitting element 100 is emitted to the outside. The black matrix 180 can solve the problem of the light emitted by adjacent light-emitting elements 100 being mixed by the first insulating interlayer 141.

[0079] A cover layer 190 may be made of an organic insulating material covering the black matrix 180 and the second electrode 170. However, the present disclosure is not necessarily limited thereto.

[0080] In Fig. 3, the configurations of the black matrix 180 and the cover layer 190 are omitted.

[0081] The contact electrode 162 may be electrically connected to the first connecting line RT1 disposed thereunder, and the first connecting line RT1 may be connected to the pixel drive circuit 20. Therefore, the cathode voltage may be applied to the second electrode 170 via the contact electrode 162. The first electrode 161 may be electrically connected to the second connecting line RT2.

[0082] With reference to Fig. 5, the contact electrode 162 may be arranged coplanar with the signal lines TL1 to TL6. The pixel drive circuit 20 may be arranged below the contact electrode 162 and the signal lines TL1 to TL6. If the pixel drive circuit 20 is a drive driver, a plurality of drive drivers may be arranged in the display panel.

[0083] A second insulating layer 133 may expose the contact electrode 162 so that the contact electrode 162 and the second electrode 170 can be electrically connected. Furthermore, the second insulating layer 133 may insulate the signal lines TL2 to TL5 and the second electrode 170.

[0084] With reference to Fig. 6, a 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.

[0085] The first electrode 161, the connecting portion 161a, the signal line TL, and / or the connecting lines RT1 and RT2 may include a single or multiple metal layers formed from materials selected from the group consisting of titanium (Ti), molybdenum (Mo), and aluminum (Al). The first electrode 161, the connecting portion 161a, the signal line TL, and / or the connecting line 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.

[0086] The first layer ML1 and the third layer ML3 may contain Ti or Mo. The second layer ML2 may contain Al. The fourth layer ML4 may contain a transparent, conductive oxide layer, e.g., indium tin oxide (ITO) or indium zinc oxide (IZO), which exhibits high adhesion to the solder structure 163 and is also corrosion and acid resistant.

[0087] 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.

[0088] The second insulating layer 133 may include an opening hole 133a disposed on the first electrode 161 and the signal line TL to expose the solder pattern 163.

[0089] The light-emitting element 100 may include a first conductive semiconductor layer 100-1, an active layer 100-2 disposed on the first conductive semiconductor layer 100-1, and a second conductive semiconductor layer 100-3 disposed on the active layer 100-2. A first electrode 214 may be disposed under the first conductive semiconductor layer 100-1, and a second electrode 212 may be disposed on the second conductive semiconductor layer 100-3.

[0090] The light-emitting element 100 can be formed on a silicon wafer using an MOCVD (metal organic chemical vapor deposition) method, a CVD (CVD) method, a plasma enhanced CVD (PECVD) method, an MBE (molecular beam epitaxy) method, an HVPE (hydride vapor phase epitaxy) method, a sputtering method, or the like.

[0091] The first conductive semiconductor layer 100-1 may be made of group III-V or group II-VI compound semiconductors and doped with a first dopant. The first conductive semiconductor layer 100-1 may be made of a semiconductor material having a composition formula of Al x1 In y1 Ga (1-x1-y1)N (0≤x1≤1, 0≤y1≤1, 0≤x1+y1≤1) or any one or more of 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, or Te, the first conductive semiconductor layer 100-1 may be an n-type nitride semiconductor layer. However, if the first dopant is a p-type dopant, the first conductive semiconductor layer 100-1 may be a p-type nitride semiconductor layer.

[0092] The active layer 100-2 is a layer where electrons (or holes) injected through the first conductive semiconductor layer 100-1 collide with holes (or electrons) injected through the second conductive semiconductor layer 100-3. The active layer 100-2 can transition to a low energy level when electrons and holes recombine, generating light of the corresponding wavelength.

[0093] The active layer 100-2 may have any of the following well structures: 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 wire structure, although the structure of the active layer 100-2 is not limited thereto. The active layer 100-2 may generate light in the visible wavelength range. For example, the active layer 100-2 may output light in any of the blue, green, and red wavelength ranges.

[0094] The second conductive semiconductor layer 100-3 may be arranged on the active layer 100-2. The second conductive semiconductor layer 100-3 may be made of group III-V or group II-VI compound semiconductors, and the second conductive semiconductor layer 100-3 may be doped with a second dopant. The second conductive semiconductor layer 100-3 may be made of a semiconductor material having the composition formula In x2 Al y2 Ga (1-x2-y2)N (0≤x2≤1, 0≤y2≤1, 0≤x2+y2≤1) or a material selected from the group consisting of, but not limited to, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. If the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductive semiconductor layer 100-3 doped with the second dopant may be a p-type semiconductor layer. If the second dopant is an n-type dopant, the second conductive semiconductor layer 100-3 may be an n-type nitride semiconductor layer.

[0095] A reflector 16 may be disposed on the side surfaces and a bottom surface of the light-emitting element 100. The reflector 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 reflector 16 may be formed as a reflector with any of various structures. The light emitted from the active layer 100-2 may be reflected upward by the reflector 16, thereby increasing the light extraction efficiency. The reflector 16 may include various conductive layers to consider light reflection efficiency and resistance.For example, the reflector 16 may use an opaque conductive layer such as silver (Ag), aluminum (Al), molybdenum (Mo), titanium (Ti) or an alloy thereof and a transparent conductive layer such as indium tin oxide (ITO) or indium zinc oxide (IZO), but the structure of the reflector 16 is not limited thereto.

[0096] Although in the exemplary embodiment, the light-emitting element 10 has been described as having a vertical structure in which the lower and upper electrodes 214 and 252 are arranged above and below the light-emitting structure, the light-emitting element may also have a lateral structure or a flip-chip structure other than the vertical structure.

[0097] With reference to Fig. 7, the main light-emitting element 102a and the sub-pixel light-emitting element 102b may be arranged on the bank structure 130. An example of the second light-emitting element will be described. A 1-1 electrode 161-1 connected to the main light-emitting element 102a may extend to one side surface of the bank structure 130 and may be electrically connected to the 2-1 connection line RT21 arranged thereunder. A 1-2 electrode 161-2 connected to the sub-pixel light-emitting element 102b may extend to the other side surface of the bank structure 130 and may be electrically connected to the 2-2 connection line RT22 arranged thereunder.

[0098] The pixel drive circuit 20 can apply the anode voltage to the main light-emitting element 102a via the 2-1 connection line RT21 and the anode voltage to the sub-light-emitting element 102b via the 2-2 connection line RT22. The pixel drive circuit 20 can apply the cathode voltage to the main light-emitting element 102a and the sub-light-emitting element 102b via the first connection line RT1 and the second electrode 170.

[0099] The pixel driving circuit 20 can adjust the brightness by driving only the main light-emitting element 102a, and it can adjust the brightness by simultaneously driving the main light-emitting element 102a and the sub-light-emitting element 102b. When the main light-emitting element 102a becomes a dark spot, the pixel driving circuit 20 can adjust the brightness by driving only the sub-light-emitting element 102b.

[0100] Fig. 8 is a view showing a display device according to another exemplary embodiment of the present disclosure. Fig. 9 is a cross-sectional view along the line IV-IV' in Fig. 8.

[0101] With reference to Fig. 8 and Fig. 9, the second electrode 170 may be electrically connected to the contact electrode 162 through a contact hole TH1 formed in the second insulating interlayer 142. The second insulating interlayer 142 may include the contact hole TH1 exposing the contact electrode 162. The second electrode 170 may be inserted into the contact hole TH1 of the second insulating interlayer 142 and may be in contact with an upper surface of the contact electrode 162. The contact hole TH1 may be formed in an outer region of the pixel.

[0102] Fig. 10 is a cross-sectional view showing a longitudinal sectional structure of a part of the display panel taken along the line II' in Fig. 1, which is an enlarged cross-sectional view of “B” in Fig. 4 is.

[0103] Fig. 11 is a cross-sectional view showing a longitudinal sectional structure of a part of the display panel taken along line II' in Fig. 1, which is an enlarged cross-sectional view of “C” in Fig. 4 is.

[0104] According to the Fig. 10 and Fig. 11, the display device 10 of the present exemplary embodiment may include the pixel driving circuit 20 formed on the substrate 110, the buffer layer 121 disposed on the pixel driving circuit 20, the connecting lines RT1 and RT2 disposed on the buffer layer 121, the insulating layer 122 disposed on the connecting lines RT1 and RT2, the bank structure 130 disposed on the insulating layer 122, the first electrode 161 disposed above the bank structure 130, and the light-emitting element 100 disposed and connected on the first electrode 161 and connected to the first electrode 161 via the solder structure 163.

[0105] The light-emitting element 100 emits light by recombination of electrons and holes according to a current flowing between the first conductive semiconductor layer 100-1 and the second conductive semiconductor layer 100-3.

[0106] The lower electrode 214 of each of the light-emitting elements 100 may be electrically connected to an anode voltage output terminal of the pixel driving circuit 20 via the solder pattern 163, the first electrode 161, and at least one wiring pattern through a pad pattern 230 formed on a lower surface thereof.

[0107] The second electrode 170 of each of the light-emitting elements 100 may be electrically connected to a cathode voltage output terminal of the pixel drive circuit 20 via the upper electrode 252 and one or more connecting lines RT1 and RT2.

[0108] Beneath the upper surfaces of the light-emitting elements 100, the bank structure 130 and the light-emitting elements 100 may be covered by the first insulating interlayer 141. The first insulating interlayer 141 may have a stacked structure of any one or more organic insulating materials and inorganic insulating materials including an oxide film or a nitride film.

[0109] A second passivation layer 220 (see Fig. 4) made of an inorganic insulating material or an organic insulating material may be further formed to surround the edge of the first insulating interlayer 141. The second insulating interlayer 142 may be disposed on the first insulating layer 122 together with the first insulating interlayer 141.

[0110] The second electrode 170 may be disposed on the first insulating interlayer 141 and commonly connected to all pixels PXLs. The second electrode 170 may be a thin metal electrode through which light is transmitted. The first electrode 161, the second electrode 170, and the black matrix 180 may be stacked in the non-emitting region of the pixel area. The second electrode 170 may be made of a transparent electrode material, such as ITO, but is not necessarily limited thereto.

[0111] The first electrode 161 can be formed as a single or multilayer metal layer made of materials selected from the group consisting of Ti, Mo, and Al. A layer of transparent electrode material selected from a material between ITO and IZO can be formed on the metal layer.

[0112] The black matrix 180 may be made of an organic insulating material to which a black pigment is added. The second electrode 170 may be in contact with the contact electrode 162 beneath the black matrix 180.

[0113] The first insulating interlayer 141 may include a contact hole (not shown) exposing the contact electrode 162. A portion of the second electrode 170 may be formed in the contact hole of the first insulating interlayer 141 so that the second electrode 170 may be in contact with the upper surface of the contact electrode 162. The contact hole (not shown) may be formed in the outer region of the pixel in such a way that it surrounds the bank structures 130.

[0114] The cap layer 190 may be made of an organic insulating material covering the black matrix 180 and the second electrode 170. An insulating layer, the same as the first insulating interlayer 141, may be formed flat between the cap layer 190 and the second electrode 170. In this case, a passivation layer (not shown) made of an inorganic insulating material or an organic insulating material may cover the second electrode 170 with a thickness less than that of the first insulating interlayer 141.

[0115] Fig. 12 is a plan view of a light-emitting element of the display panel according to an exemplary embodiment of the present description.

[0116] Fig. 13 is a cross-sectional view showing a longitudinal sectional structure of a part of the light-emitting element taken along the line VV' in Fig. 12 shows.

[0117] With reference to Fig. 12 and Fig. 13, the light-emitting element 100 according to the exemplary embodiment of the present description can be arranged by placing it on the substrate (not shown, 110 in Fig. 10) arranged structure (not shown, 130 in Fig. 10) and overlaps the bank structure 130.

[0118] In addition, the light-emitting element 100 may be in contact with the first electrode (not shown, 161 in Fig. 10) arranged on the bench structure 130 and overlap the first electrode 161.

[0119] The light-emitting layer 100a may include a bottom surface on which the bottom electrode 214 is disposed, an upper surface on which the top electrode 252 is disposed, and side surfaces between the bottom surface and the top surface.

[0120] First and second flat protrusions 100a-1 and 100a-2, on which the lower electrode 214 and the upper electrode 252 are disposed, may be formed on the lower and upper surfaces of the light-emitting layer 100a. For example, the first flat protrusion 100a-1, on which the lower electrode 214 is disposed, may be formed on the lower surface of the light-emitting layer 100a, and the second flat protrusions 100a-2, on which the upper electrode 252 is disposed, may be formed on the upper surface of the light-emitting layer 100a. Stepped portions (not shown) may be formed on the side surfaces of the first and second flat protrusions 100a-1 and 100a-2. For example, the stepped portions (not shown) may be formed on the side surfaces of each of the first and second flat protrusions 100a-1 and 100a-2. However, the present disclosure is not limited to this.

[0121] The stepped parts have a lower height than the first and second flat protrusions 100a-1 and 100a-2, and the reflector 16 may be arranged on at least a part of the side surfaces of the light-emitting element 100 below the stepped parts.

[0122] An area of ​​the light-emitting element 100 may be smaller than or equal to the areas of the bank structure 130 and the first electrode 161. However, the present disclosure is not necessarily limited thereto. For process tolerance, the area of ​​the first electrode 161 may preferably be larger than the area of ​​the light-emitting element 100.

[0123] As in Fig. 10, the light-emitting element 100 may include the light-emitting layer 100a having the first conductive semiconductor layer 100-1, the second conductive semiconductor layer 100-3, and the active layer 100-2 disposed therebetween, the lower electrode 214 in contact with the first conductive semiconductor layer 100-1 of the light-emitting layer 100a, the upper electrode 214 in contact with the second conductive semiconductor layer 100-3 of the light-emitting layer 100a, and the reflector 16 covering the side surfaces and the bottom surfaces of the light-emitting layer 100a and the lower electrode 214.

[0124] The reflector 16 may include first and second passivation layers 216 and 220 surrounding the light-emitting layer 100a and the bottom electrode 214, and a reflective layer 218 disposed therebetween.

[0125] The first and second passivation layers 216 and 220 can be used as insulating layers or protective layers.

[0126] The lower electrode 214, which is in contact with the first conductive semiconductor layer 100-1, may include an anode, and the upper electrode 252, which is in contact with the second conductive semiconductor layer 100-3, may include a cathode. The light-emitting layer 100a may include one or more quantum well layers. The doped first and second conductive semiconductor layers 100-1 and 100-3 and the active layer 100-2 of the light-emitting element 100 may be made of group II-VI or group III-V compound semiconductors. The light-emitting element 100 may be fabricated on a semiconductor substrate by a separate manufacturing process and disposed on the solder structure 163 by the transfer process.

[0127] The light-emitting layer 100a of the light-emitting element 100 according to the present exemplary embodiment is a PN junction structure in which the first conductive semiconductor layer 100-1, the active layer 100-2, and the second conductive semiconductor layer 100-3 are sequentially formed.

[0128] Furthermore, the side surfaces of the lower electrode 214 and the light-emitting layer 100a are surrounded by the first and second passivation layers 216 and 220, which form the reflector 16, and the reflective layer 218 is formed so that the light of the light-emitting element 100 can be reflected and emitted to the outside between the first and second passivation layers 216 and 220.

[0129] The pad structure 230 is formed on the lower surface of the light-emitting element 100, and the pad structure 230 is connected to the solder structure 163 formed on the first electrode 161 arranged above the bank structure 130.

[0130] The light-emitting element 100 may be formed in the shape of an inverted trapezoid whose width increases from the bottom to a central part.

[0131] The area of ​​the light-emitting element 100 may be smaller than or equal to the areas of the bank structure 130 and the first electrode 161. However, the present disclosure is not necessarily limited thereto.

[0132] The width between the left and right side surfaces of the middle light-emitting layer part 100a of the light-emitting element 100 may be larger than the width between the left and right side surfaces of the lower and upper parts thereof.

[0133] The width between the left and right side surfaces of the lower part and the width between the left and right side surfaces of the upper part of the light-emitting element 100 may be smaller than the width between the left and right side surfaces of the middle part thereof.

[0134] Portions of the light-emitting layer 100a under both sides of the upper electrode 252 of the light-emitting element 100 may be exposed. However, the present disclosure is not necessarily limited thereto.

[0135] The first and second passivation layers 216 and 220 may be arranged in such a form that they surround the entirety of the side surfaces except for a part of the upper light-emitting layer part 100a of the light-emitting element 100 and the side surfaces and the lower surface of the lower electrode 214.

[0136] The light-emitting element 100 is separated from a growth substrate 210 before being transferred to the panel and arranged on a support substrate 250.

[0137] When the active layer 100-2, which is an epi-structure, is separated from the growth substrate 210, a laser (Laser Lift Off (LLO)) is irradiated from a laser source onto the growth substrate, so that the support substrate 250 is made of a material that can transmit the laser. The growth substrate 210 can be made of sapphire, for example.

[0138] The support substrate 250 may be made of polymer resin, glass, quartz, a resin film, a transparent substrate, and a transparent flexible polymer substrate.

[0139] The first conductive semiconductor layer 100-1, which forms the light-emitting layer 100a, is a semiconductor layer in which positively charged holes move as charge carriers to generate a current, and may be made of a P-GaN-based material. The P-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the P-type semiconductor layer may include Mg, Zn, Be, etc.

[0140] The lower electrode 214 is formed on the first conductive semiconductor layer 100-1 to form an ohmic contact, and the pad structure 230 is formed on the lower surface of the lower electrode 214. When the light-emitting element 100 is transferred to the panel, the light-emitting element 100 may be in contact with a pixel electrode (not shown) to receive a voltage corresponding to a data voltage through a TFT.

[0141] The second conductive semiconductor layer 100-3 is a semiconductor layer in which free electrons with negative charges move as charge carriers to generate a current, and may be made of an n-GaN-based material. The n-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the second conductive semiconductor layer 100-3 may include Si, Ge, Se, Te, C, etc. Furthermore, in some cases, a buffer layer, such as an undoped GaN-based semiconductor layer, may be additionally formed between the growth substrate 210 and the n-type semiconductor layer.

[0142] The active layer 100-2 may be disposed on the first conductive semiconductor layer 100-1 and may comprise an MQW structure including a well layer and a barrier layer with a higher band gap than the well layer. The active layer 100-2 may, for example, comprise an MQW structure, such as InGaN / GaN.

[0143] Furthermore, the first and second passivation layers 216 and 220 forming the reflector 16 are arranged to surround the bottom surfaces and side surfaces of the light-emitting layer 100a and the lower electrode 214. Each of the first and second passivation layers 216 and 220 can be formed as a multilayer or single-layer film of an inorganic material.

[0144] The first and second passivation layers 216 and 220 can be used as insulating layers or protective layers.

[0145] The first and second passivation layers 216 and 220 may be made of any of the following materials: SiO2, SiN 34 , and a resin or an oxide containing at least one of the elements Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag and Al.

[0146] The inorganic material may, for example, be a metal oxide or metal nitride, and in particular the inorganic material may contain at least one of the following materials: SiO2, SiN x , SiON, Al2O3, TiO2, Ta2O5, HfO2, and ZrO2.

[0147] Furthermore, the reflective layer 218 may be disposed between the first and second passivation layers 216 and 220 and overlap the bottom surfaces and side surfaces of the lower electrode 214 and the light-emitting layer 100a. The reflective layer 218 reflects the light generated in the light-emitting element 100 and emits the reflected light upward from the light-emitting element 100.

[0148] The reflective layer 218 may be formed as a single or multiple metal layers made of one or more of the metals Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, and Cu. In particular, a metal layer material with high light reflectivity may preferably be used as the material of the reflective layer 218. In the present exemplary embodiment, aluminum (Al) is used as the material of the reflective layer 218. However, the present disclosure is not limited thereto.

[0149] The lower electrode 214 may be in contact with the first conductive semiconductor layer 100-1 of the light-emitting layer 100a, and the upper electrode 212 may be in contact with the second conductive semiconductor layer 100-3.

[0150] The lower electrode 214 and the upper electrode 252 may be made of, but are not necessarily limited to, a transparent or translucent electrode material. The transparent or translucent electrode material may include one or more materials from the group consisting of ITO, IZO, zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and aluminum zinc oxide (AZO).

[0151] In addition, the pad structure 230 may be formed on the lower surface of the lower electrode 214 to form an ohmic contact.

[0152] The pad structure 230 may be formed in a stacked structure of a first metal layer 230a, a second metal layer 230b, a third metal layer 230c, and a fourth metal layer 230d, or in a single-layer structure of any of the above-mentioned metal layers, but is not necessarily limited thereto.

[0153] When the pad structure 230 has a stacked structure, the second and third metal layers 230b and 230c may be formed between the first metal layer 230a and the fourth metal layer 230d. Although each of the first to fourth metal layers 230a to 230d may be made of any one of Au, Al, and Ni or an alloy thereof, and the first and fourth metal layers 230a and 230d may be made of a different metal than the second and third metal layers 230b and 230c, the present disclosure is not limited thereto. The second metal layer 230b may be made of a different metal than the first, third, and fourth metal layers 230a, 230c, and 230d. For example, the first and fourth metal layers 230a and 230d may contain gold (Au), the second metal layer 230b may contain aluminum (Al), and the third metal layer 230c may contain nickel (Ni).

[0154] However, the number of layers of the stacked structure of the pad structure 230 is not limited to one or four layers; the number of layers of the stacked structure of the pad structure 230 may be n (where n is an integer). For example, when the pad structure 230 has a stacked structure, the second, third, and fourth metal layers may be formed between the first metal layer and the fifth metal layer. Each of the first to fifth metal layers may be made of any one of the metals Au, Al, and Ni or an alloy thereof, and at least one of the first to fifth metal layers may be made of a different metal than the other layers, but the present disclosure is not limited thereto.

[0155] When the light-emitting element 100 formed on the growth substrate 210 (see Fig. 14A) over the carrier substrate 250 onto the substrate 110 (see Fig. 10), the lower electrode 214 is connected to the pixel electrode (not shown) via the pad structure 230, and thus a positive voltage is applied to the lower electrode 214, which is in contact with the first conductive semiconductor layer 100-1 via the pixel electrode, and a negative voltage is applied to the upper electrode 252, which is in contact with the first conductive semiconductor layer 100-1 via the second electrode 170. Therefore, a current flows between the pixel electrode (not shown) and the second electrode 170 due to the movement of electrons of the second conductive semiconductor layer 100-3 and the flow of holes of the first conductive semiconductor layer 100-1.

[0156] Furthermore, the light-emitting layer 100a emits light by recombination of electrons and holes according to the current flowing between the pixel electrode and the second electrode 170.

[0157] Therefore, the light generated in the light-emitting element 100 is reflected by the reflective layer 218 arranged in the first and second passivation layers 216 and 220 and emitted upward from the light-emitting element 100.

[0158] Next, a process for manufacturing the light-emitting element of the display device according to an exemplary embodiment of the present specification will be described.

[0159] Fig. 14A to 14T are cross-sectional views showing a process for manufacturing the light-emitting element of the display device according to an exemplary embodiment of the present specification.

[0160] With reference to Fig. 14A, the growth substrate 210 is provided for forming an epi structure of one of the types RED, GREEN and BLUE, which constitute the light-emitting element.

[0161] The growth substrate 210 may be formed as a conductive or insulating substrate. The growth substrate 210 may be made of at least one of the following: sapphire, SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga2O3. However, the present disclosure is not necessarily limited thereto.

[0162] Subsequently, the first conductive semiconductor layer 100-1, the active layer 100-2 and the second conductive semiconductor layer 100-3, which form a light-emitting layer part 100a', are sequentially deposited on the growth substrate 210.

[0163] The first conductive semiconductor layer 100-1, the active layer 100-2, and the second conductive semiconductor layer 100-3 may be formed using an MOCVD method, a CVD method, a PECVD method, an MBE method, an HVPE method, or an epitaxial method.

[0164] The first conductive semiconductor layer 100-1 is a semiconductor layer in which holes with positive charges move as charge carriers to generate a current.

[0165] The first conductive first semiconductor layer 100-1 may comprise a semiconductor material having the composition formula In x Al y Ga 1-x-y N (0≤x≤1, 0≤xy≤1, 0≤x+y≤1, selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN and AlInN) and doped with a p-type dopant such as Mg, Zn, Ca, Sr or Ba.

[0166] Alternatively, the first conductive semiconductor layer 100-1 may be made of a P-GaN-based material. The P-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the P-type semiconductor layer may include Mg, Zn, Be, etc.

[0167] The second conductive semiconductor layer 100-3 is a semiconductor layer in which free electrons with negative charges move as charge carriers to generate a current.

[0168] The second conductive semiconductor layer 100-3 may be formed, for example, by inserting an n-type semiconductor layer. The second conductive semiconductor layer 100-3 may be a semiconductor material having a composition formula of In x Al y Ga 1-x-y N (0≤x≤1, 0≤xy≤1, 0≤x+y≤1, selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN and AlInN, and doped with an n-type dopant such as Si, Ge or Sn.

[0169] Alternatively, the second conductive semiconductor layer 100-3 may also be made of an n-GaN-based material. The n-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the second conductive semiconductor layer 100-3 may include Si, Ge, Se, Te, C, etc.

[0170] Moreover, the present exemplary embodiment is not limited thereto, and the first conductive semiconductor layer 100-1 may include an n-type semiconductor layer, and the second conductive semiconductor layer 100-3 may include a p-type semiconductor layer.

[0171] The active layer 100-2 is a region where electrons and holes recombine, and when the electrons and holes recombine, the active layer 100-2 can transition to a lower energy level to produce light of the corresponding wavelength.

[0172] The active layer 100-2 can, for example, be made of a semiconductor material with the composition formula In x Al y Ga 1-x-y N (0x≤1, 0≤yx≤1, 0≤x+y≤1) and are formed in a single quantum well structure or an MQW structure.

[0173] Furthermore, the active layer 100-2 may include a quantum wire structure or a quantum dot structure.

[0174] The active layer 100-2 may be disposed on the first conductive semiconductor layer 100-1 and may comprise an MQW structure including a well layer and a barrier layer with a higher band gap than the well layer. The active layer 100-2 may, for example, comprise an MQW structure, such as InGaN / GaN.

[0175] Subsequently, with reference to Fig. 14B, a first flat protrusion 100a-1 is formed by removing a part of the light-emitting layer part 100a' in a region excluding a region used as an active layer by selectively patterning the light-emitting layer part 100a'.

[0176] Next, with reference to Fig. 14C, a lower electrode layer 214a made of a transparent conductive material such as ITO or IZO, which is used as an electrode, is applied to the light-emitting layer part 100a'.

[0177] The lower electrode layer 214a may be made of, but is not necessarily limited to, a transparent or translucent electrode material. The transparent or translucent electrode material may include one or more materials from the group consisting of ITO, IZO, ZnO, In2O3, IGO, and AZO.

[0178] Subsequently, with reference to Fig. 14D, by performing a patterning process using a photographic method to selectively remove the lower electrode layer 214a and the underlying light-emitting layer portion 100a', the light-emitting element regions are separated, and the lower electrode 214 and the light-emitting layer 100a of the light-emitting element are formed. In this case, the lower electrode 214 may be formed on the first protrusion 100a-1 of the light-emitting layer 100a.

[0179] Next, with reference to Fig. 14E, a first passivation layer portion 216a is formed on the growth substrate 210, which includes the lower electrode 214 and the light-emitting layer 100a. The first passivation layer portion 216a may be formed as a multilayer or single-layer film made of an inorganic or organic material.

[0180] The first passivation layer portion 216a may be made of any of the following materials: SiO2, SiN 34 , and a resin or an oxide containing at least one of the elements Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag and Al.

[0181] The inorganic material may, for example, be a metal oxide or metal nitride, and in particular the inorganic material may contain at least one of the following: SiO2, SiN x , SiON, Al2O3, TiO2, Ta2O5, HfO2, and ZrO2.

[0182] Subsequently, with reference to Fig. 14F, the first passivation layer 216, which delimits each of the light-emitting regions, is formed by selectively patterning the first passivation layer part 216a.

[0183] The first passivation layer 216 may be disposed on the side surfaces of the light-emitting layer 100a as well as on the side surfaces and the bottom surface of the lower electrode 214.

[0184] Subsequently, with reference to Fig. 14G, a metal layer 218a used as a reflecting mirror is formed on the growth substrate 210, which includes the first passivation layer 216 formed on the separated region of the light-emitting element.

[0185] The metal layer 218a may be formed as a single layer or as multiple layers of one or more of Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, and Cu. In particular, a material with high light reflectivity may preferably be used as the material of the metal layer 218a. In the present exemplary embodiment, a case where aluminum (Al) is used as the material of the metal layer 218a is described, but the present disclosure is not limited thereto.

[0186] Next, with reference to Fig. 14H, the reflective layer 218 is formed in each region of the light-emitting element by selectively patterning the metal layer 218a through the photolithographic process. When the metal layer 218a is patterned, the portion of the first passivation layer 216 disposed beneath the metal layer 218a is simultaneously removed along with the metal layer 218a disposed on the light-emitting element region, thus also exposing a portion of the lower electrode 214.

[0187] Subsequently, with reference to Fig. 14I, a second passivation layer portion 220a is formed on the growth substrate 210, which includes the reflective layer 218 and the exposed portion of the lower electrode 214. The second portion of the passivation layer 220a may be formed as a multilayer or single-layer film of an inorganic material.

[0188] The second passivation layer part 220a may be made of any one of the group consisting of: SiO2, SiN 34 , and a resin or an oxide containing at least one of the elements Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag and Al.

[0189] The inorganic material may, for example, be a metal oxide or metal nitride, and in particular the inorganic material may contain at least one of: SiO2, SiN x , SiON, Al2O3, TiO2, Ta2O5, HfO2, and ZrO2.

[0190] When the second passivation layer portion 220a is formed, the second passivation layer portion 220a may be made of a material that is identical to or different from that of the first passivation layer portion 216a.

[0191] Next, with reference to Fig. 14J, the second passivation layer 220, which delimits each of the light-emitting regions, is formed by selectively patterning the second passivation layer part 220a.

[0192] During the structuring of the second passivation layer 220a, the second passivation layer portion 220a in contact with the lower electrode 214 and a surface of the growth substrate 210 may also be removed.

[0193] As described above, the reflector 16 may include the first passivation layer 216, the second passivation layer 220, and the reflective layer 218 disposed therebetween.

[0194] The reflective layer 218 forming the reflector 16 may be disposed in a shape surrounded by the first passivation layer 216 and the second passivation layer 220. Furthermore, the first and second passivation layers 216 and 220 may be disposed in such a way as to surround the side surfaces of the light-emitting layer 100a and the side surfaces and upper surface of the lower electrode 214. Furthermore, the reflective layer 218 may be disposed between the first and second passivation layers 216 and 220 to overlap the side surfaces of the light-emitting layer 100a and the side surfaces and upper surface of the lower electrode 214.

[0195] Subsequently, with reference to Fig. 14K, the pad structure 230 is formed in contact with the lower electrode 214 by depositing the metal material layer on the entire surface of the growth substrate 210, including the exposed part of the lower electrode 214 and the second passivation layer 220, and selectively patterning the metal material layer.

[0196] The pad structure 230 may be formed in a stacked structure of the first metal layer 230a, the second metal layer 230b, the third metal layer 230c, and the fourth metal layer 230d, or in a single layer structure of any of the above-mentioned metal layers, but is not necessarily limited thereto.

[0197] When the pad structure 230 has a stacked structure, the second and third metal layers 230b and 230c may be disposed between the first metal layer 230a and the fourth metal layer 230d. Although each of the first to fourth metal layers 230a to 230d may be made of any one of Au, Al, and Ni or an alloy thereof, and the first and fourth metal layers 230a and 230d may be made of a different metal than the second and third metal layers 230b and 230c, the present disclosure is not limited thereto. The second metal layer 230b may be made of a different metal than the first, third, and fourth metal layers 230a, 230c, and 230d. For example, the first and fourth metal layers 230a and 230d may contain gold (Au), the second metal layer 230b may contain aluminum (Al), and the third metal layer 230c may contain nickel (Ni).

[0198] However, the number of layers of the stacked structure of the pad structure 230 is not limited to one or four layers; the number of layers of the stacked structure of the pad structure 230 may be n (where n is an integer). For example, when the pad structure 230 has a stacked structure, the second, third, and fourth metal layers may be formed between the first metal layer and the fifth metal layer. Each of the first to fifth metal layers may be made of any one of Au, Al, and Ni, or an alloy thereof, and at least one of the first to fifth metal layers may be made of a different metal than the other layers, but the present disclosure is not limited thereto.

[0199] Next, with reference to Fig. 14L, a sacrificial layer 232a is formed on the entire surface of the entire structure of the growth substrate 210, which includes the pad structure 230. Any insulating material including SiO2, SiN, and the like can be used as the insulating layer 232a.

[0200] Subsequently, with reference to Fig. 14M, the region of the light-emitting element is separated by selectively patterning the sacrificial layer 232a through the masking process, and at the same time, a contact hole 234h is formed, exposing a part of the pad structure 230.

[0201] With reference to Fig. 14N, the process of fabricating the light-emitting element on the growth substrate 210 is completed by forming a dummy insulating layer 236a on the entire surface of the growth substrate 210, including the remaining sacrificial layers 232, to planarize the growth substrate 210. The material of the dummy insulating layer 236a can be selected from benzocyclobutene (BCB) or other insulating materials.

[0202] The following describes a process of arranging and connecting the light-emitting element on the carrier substrate.

[0203] The support substrate 250 is provided, and a substrate separation process for separating the light-emitting element from the growth substrate 210 is performed to transfer the light-emitting element to the support substrate 250.

[0204] The support substrate 250 may be made of polymer resin, glass, quartz, a resin film, a transparent substrate, and a transparent flexible polymer substrate.

[0205] With reference to Fig. 14O, a structure formed on the growth substrate 210 is placed and bonded to the support substrate 250. Although not shown in the drawing, to laminate the growth substrate 210 in an inverted state to the support substrate 250, an ultraviolet-reactive resin layer (not shown), which can be used as an adhesive layer, may be formed on the support substrate 250.

[0206] In this case, in the state of inversion of the growth substrate 210, a part of the dummy insulating layer 236a is arranged and bonded on the support substrate 250 and exposes the growth substrate 210 to the outside.

[0207] Next, with reference to Fig. 14P, after the light-emitting element part of the growth substrate 210 is in contact with the ultraviolet-reactive resin layer (not shown) of the support substrate 250, a laser is irradiated onto a boundary between the light-emitting element part and the growth substrate 210.

[0208] The laser emitted from the laser source after passing through the growth substrate 210 can separate the light-emitting element portion from the growth substrate 210. In this case, the light-emitting element portion can remain in contact with the ultraviolet-reactive resin layer (not shown) of the support substrate 250.

[0209] Subsequently, with reference to Fig. 14Q, after the growth substrate 210 is removed by laser radiation, an upper electrode layer 252a is formed on the first and second passivation layers 216 and 220 including the light-emitting layer 100a, which is the exposed area of ​​the part of the light-emitting element, the reflective layer 218 arranged between the first and second passivation layers 216 and 220, the sacrificial layer 232, and the dummy insulating layer 236a.

[0210] The upper electrode layer 252a may be made of, but is not necessarily limited to, a transparent or translucent electrode material. The transparent or translucent electrode material may include one or more materials selected from the group consisting of ITO, IZO, ZnO, In2O3, IGO, and AZO. In the present disclosure, an example of a case where ITO is used as the transparent electrode material is described.

[0211] Next, with reference to Fig. 14R, the upper electrode 252 is formed on the light-emitting layer 100a by selectively patterning the upper electrode layer 252a through a masking process. In this case, when patterning the upper electrode layer 252a, upper portions of the first and second passivation layers 216 and 220, including the side surfaces of the light-emitting layer 100a and the upper electrode layer 252a, an upper portion of the reflective layer 218 disposed between the first and second passivation layers 216 and 220, and upper portions of portions of the sacrificial layer 232 and the dummy insulating layer 236a may be etched together.

[0212] The second flat protrusion 100a-2 may be formed on the upper surface of the light-emitting layer 100a, and stepped parts (not shown) may be formed on the side surfaces of the light-emitting layer 100a.

[0213] As described above, the light-emitting layer 100a, the lower electrode 214, the upper electrode 252, and the reflective layer 218 disposed between the first and second passivation layers 216 and 220 are formed, surrounding the side surfaces and the lower surfaces of the light-emitting layer 100a and the lower electrode 214 constituting the light-emitting element 100 (see Fig. 14T).

[0214] Subsequently, with reference to Fig. 14S, the dummy insulating layer 236a arranged between the sacrificial layers 232 is selectively removed in the externally exposed areas by a dry etching process.

[0215] With reference to Fig. 14T, the light-emitting element 100 remains on the carrier substrate 250 by removing the remaining sacrificial layers 232 through a wet etching process.

[0216] As described above, the process of separating the light-emitting element 100 according to an exemplary embodiment of the present disclosure from the growth substrate 210 and bonding the light-emitting element 100 to the support substrate 250 is completed.

[0217] Meanwhile, a light-emitting element of a display device according to another exemplary embodiment of the present specification will be described below.

[0218] Fig. 15 is a plan view of a light-emitting element of a display device according to another exemplary embodiment of the present specification.

[0219] Fig. 16 is a cross-sectional view showing a longitudinal sectional structure of a part of the light-emitting element taken along the line VI-VI' in Fig. 15 shows.

[0220] With reference to Fig. 15 and Fig. 16, a light-emitting element 300 according to another exemplary embodiment of the present description may be transferred and deposited on the bank structure (not shown, 130 in Fig. 10) are arranged on the substrate (not shown, 110 in Fig. 10) is arranged to overlap the bench structure 130.

[0221] In addition, the light-emitting element 300 may be in contact with the first electrode (not shown, 161 in Fig. 10) arranged on the bench structure 130 to overlap the first electrode 161.

[0222] An area of ​​the light-emitting element 300 may be smaller than or equal to the areas of the bank structure 130 and the first electrode 161. However, the present disclosure is not necessarily limited thereto. Furthermore, for process tolerance, the area of ​​the first electrode 161 may preferably be larger than the area of ​​the light-emitting element 300.

[0223] As in Fig. 15, the light-emitting element 300 may include a light-emitting layer 300a having a first conductive semiconductor layer 300-1, a second conductive semiconductor layer 300-3, and an active layer 300-2 disposed therebetween, a lower electrode 314 in contact with the first conductive semiconductor layer 300-1 of the light-emitting layer 300a, an upper electrode 312 in contact with the second conductive semiconductor layer 300-3 of the light-emitting layer 300a, and a reflector 36 covering the side surfaces and the bottom surfaces of the light-emitting layer 300a and the lower electrode 314.

[0224] The reflector 36 may include first and second passivation layers 316 and 320 surrounding the light-emitting layer 300a and the bottom electrode 314, and a reflective layer 318 disposed therebetween.

[0225] The first and second passivation layers 316 and 320 can be used as insulating layers or protective layers.

[0226] The lower electrode 314, which is in contact with the first conductive semiconductor layer 300-1, may include an anode, and the upper electrode 352, which is in contact with the second conductive semiconductor layer 300-3, may include a cathode.

[0227] The light-emitting layer 300a may include one or more quantum well layers. The doped first and second conductive semiconductor layers 300-1 and 300-3 and the active layer 300-2 of the light-emitting element 300 may be made of group II-VI or group III-V compound semiconductors. The light-emitting element 300 may be formed by a separate process on a semiconductor substrate and deposited by the transfer process on a solder structure (not shown, 162 in Fig. 10) may be arranged.

[0228] The light-emitting layer 300a may include a bottom surface on which the bottom electrode 314 is disposed, an upper surface on which the top electrode 352 is disposed, and side surfaces or edge portions between the bottom and top surfaces.

[0229] The lower surface of the light-emitting layer 300a may include a first flat protrusion 300a-1 on which the lower electrode 314 is disposed. The upper surface of the light-emitting layer 300a may include a second flat protrusion 300a-2 on which the upper electrode 352 is disposed. The first and second flat protrusions 300a-1 and 300a-2 may include stepped portions (not shown) formed on their side surfaces. For example, each of the first and second flat protrusions 300a-1 and 300a-2 may include stepped portions (not shown) formed on their side surfaces. However, the present disclosure is not limited thereto.

[0230] The stepped parts have a lower height than the first and second flat protrusions 300a-1 and 300a-2, and the reflector 36 may be arranged on at least a part of the side surfaces of the light-emitting element 300 below the stepped parts.

[0231] The lower electrode 314, which is in contact with the first conductive semiconductor layer 300-1, may include an anode, and the upper electrode 352, which is in contact with the second conductive semiconductor layer 300-2, may include a cathode. The light-emitting layer 300a may include one or more quantum well layers. The doped first and second conductive semiconductor layers 300-1 and 300-3 and the active layer 300-2 of the light-emitting element 300 may be made of group II-VI or group III-V compound semiconductors. The light-emitting element 300 may be formed by a separate process on a semiconductor substrate and deposited by the transfer process on the solder structure 163 (see Fig. 10) may be arranged.

[0232] The light-emitting layer 300a of the light-emitting element 300 according to another exemplary embodiment of the present disclosure is a PN junction structure in which the first conductive semiconductor layer 300-1, the active layer 300-2, and the second conductive semiconductor layer 300-3 are sequentially formed.

[0233] Furthermore, the outer surfaces of the lower electrode 314 and the light-emitting layer 300a are surrounded by the first and second passivation layers 316 and 320, and the reflective layer 318 is formed so that the light of the light-emitting element 300 can be reflected and emitted outward between the first and second passivation layers 316 and 320.

[0234] On the lower surface of the light-emitting element 300, a pad structure 324 is formed, and the pad structure 324 is connected to the solder structure 163 formed on the first electrode 161 arranged above the bank structure (not shown, 130 in Fig. 10).

[0235] As in Fig. 17K, which will be described below, the pad structure 324 may be formed in a stacked structure of a first metal layer 324a, a second metal layer 324b, a third metal layer 324c, and the fourth metal layer 324d, or in a single layer structure of a single metal layer, which is any of the above-mentioned metal layers, but is not necessarily limited thereto.

[0236] When the structure of the pad 324 is a stacked structure, the second and third metal layers 324b and 324c may be formed between the first metal layer 324a and the fourth metal layer 324d. Although each of the first to fourth metal layers 324a to 324d may be made of any one of gold (Au), aluminum (Al), and nickel (Ni), or an alloy thereof, and the first and fourth metal layers 324a and 324d may be made of a different metal than the second and third metal layers 324b and 324c, the present disclosure is not limited thereto. The second metal layer 324b may be made of a different metal than the first, third, and fourth metal layers 324a, 324c, and 324d. For example, the first and fourth metal layers 324a and 324d may contain gold (Au), the second metal layer 324b may contain aluminum (Al), and the third metal layer 324c may contain nickel (Ni).

[0237] However, the number of layers of the stacked structure of the pad structure 324 is not limited to one or four layers; the number of layers of the stacked structure of the pad structure 324 may be n (where n is an integer). For example, when the pad structure 324 has a stacked structure, the second, third, and fourth metal layers may be formed between the first metal layer and the fifth metal layer. Each of the first to fifth metal layers may be made of any one of Au, Al, and Ni or an alloy thereof, and at least one of the first to fifth metal layers may be made of a different metal than the other layers, but the present disclosure is not limited thereto.

[0238] The light-emitting element 300 is separated from a growth substrate 310 before being transferred to the panel and arranged on a support substrate 350.

[0239] When the light-emitting layer 300a, which is an epi-structure, is separated from the growth substrate 310, a laser (laser lift-off (LLO)) is irradiated from the laser source onto the growth substrate. Therefore, the support substrate 350 is made of a material that can transmit the laser. The growth substrate 310 can be made of sapphire, for example.

[0240] The support substrate 350 may be made of polymer resin, glass, quartz, a resin film, a transparent substrate, and a transparent flexible polymer substrate.

[0241] The first conductive semiconductor layer 300-1, which forms the light-emitting layer 300a, is a semiconductor layer in which positively charged holes move as charge carriers to generate a current, and may be made of a P-GaN-based material. The P-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the P-type semiconductor layer may include Mg, Zn, Be, etc.

[0242] The pad structure 324 is formed on the first conductive semiconductor layer 300-1 to form an ohmic contact. When the light-emitting element 300 is transferred to the panel, the light-emitting element 100 can be in contact with a pixel electrode (not shown) to receive a voltage corresponding to a data voltage through a TFT.

[0243] The second conductive semiconductor layer 300-3 is a semiconductor layer in which free electrons with negative charges move as charge carriers to generate a current, and may be made of an n-GaN-based material. The n-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the n-type semiconductor layer 212c may include Si, Ge, Se, Te, C, etc. Furthermore, in some cases, a buffer layer, such as an undoped GaN-based semiconductor layer, may be additionally formed between the growth substrate 210 and the n-type semiconductor layer.

[0244] The active layer 300-2 may be disposed on the first conductive semiconductor layer 300-1 and may comprise an MQW structure including a well layer and a barrier layer with a higher band gap than the well layer. The active layer 300-2 may, for example, comprise an MQW structure, such as InGaN / GaN.

[0245] Furthermore, the first and second passivation layers 316 and 320 are arranged to surround the bottom surfaces and the side surfaces of the light-emitting layer 300a and the bottom electrode 314. Each of the first and second passivation layers 316 and 320 can be formed as a multilayer or single-layer film made of an inorganic material.

[0246] The first and second passivation layers 316 and 320 may be made of any material selected from the group consisting of SiO2, Si N 34 and a resin or an oxide containing at least one of the elements Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag and Al.

[0247] The inorganic material may be a metal oxide or metal nitride, and in particular the inorganic material may contain at least one of the following: SiO2, SiN x , SiON, Al2O3, TiO2, Ta2O5, HfO2, and ZrO2.

[0248] Furthermore, the reflective layer 318 may be disposed between the first and second passivation layers 316 and 320 and overlap the bottom surfaces and side surfaces of the lower electrode 314 and the light-emitting layer 300a. The reflective layer 318 reflects the light generated in the light-emitting element 300 and emits the reflected light upward from the light-emitting element 300.

[0249] The reflective layer 318 can be formed as a single or multilayer metal layer made of one or more of the following materials: Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, and Cu. In particular, a material with a high light reflectance can preferably be used as the material of the reflective layer 318. In the present embodiment, aluminum (Al) is used as the material of the reflective layer 318.

[0250] The lower electrode 314 may be in contact with the first conductive semiconductor layer 300-1 of the light-emitting layer 300a, and the upper electrode 352 may be in contact with the second conductive semiconductor layer 300-3.

[0251] The lower electrode 314 and the upper electrode 352 may be made of, but are not necessarily limited to, a transparent or translucent electrode material. The transparent or translucent electrode material may include one or more materials selected from the group consisting of ITO, IZO, ZnO, In2O3, IGO, and AZO.

[0252] In addition, the pad structure 330 may be formed on the lower surface of the lower electrode 314 to form an ohmic contact.

[0253] When the light-emitting element 300 formed on the growth substrate 310 (see Fig. 17A) onto the panel substrate (not shown, 110 in Fig. 10) is transmitted through the support substrate 350, the lower electrode 314 is connected to the pixel electrode (not shown) through the pad structure 324, and thus a positive voltage is applied to the lower electrode 314 in contact with the first conductive semiconductor layer 300-1 through the pixel electrode, and a negative voltage is applied to the upper electrode 352 in contact with the second conductive semiconductor layer 300-3 through the second electrode 170 (see Fig. 10). Therefore, a current flows between the pixel electrode (not shown) and the second electrode (not shown, 170 in Fig. 10) by the movement of electrons of the second conductive semiconductor layer 300-3 and the flow of holes of the first conductive semiconductor layer 300-1.

[0254] Furthermore, the light-emitting layer 300a emits light by recombination of electrons and holes according to the current flowing between the pixel electrode and the second electrode 170.

[0255] Therefore, the light generated in the light-emitting element 300 is reflected by the reflective layer 318 arranged in the first and second passivation layers 316 and 320 and emitted upward from the light-emitting element 300.

[0256] Next, a process for manufacturing the light-emitting element of the display device according to another exemplary embodiment of the present specification will be described.

[0257] Fig. 17A to 17T are cross-sectional views showing a process for manufacturing the light-emitting element of the display device according to another exemplary embodiment of the present specification.

[0258] With reference to Fig. 17A, the growth substrate 310 is provided for forming an epi structure of one of the types RED, GREEN and BLUE, which constitute the light-emitting element.

[0259] The growth substrate 310 may be formed as a conductive or insulating substrate. For example, the growth substrate 310 may be made of at least one of the following materials: sapphire, SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga2O3. However, the present disclosure is not necessarily limited thereto.

[0260] Next, the first conductive semiconductor layer 300-1, the active layer 300-2, and the second conductive semiconductor layer 300-3, which form a light-emitting layer part 300a', are sequentially deposited on the growth substrate 310.

[0261] The first conductive semiconductor layer 300-1, the active layer 300-2, and the second conductive semiconductor layer 300-3 may be formed using an MOCVD method, a CVD method, a PECVD method, an MBE method, an HVPE method, or an epitaxial method.

[0262] The first conductive semiconductor layer 300-1 is a semiconductor layer in which holes with positive charges move as charge carriers to generate a current.

[0263] The first conductive semiconductor layer 300-1 may comprise a semiconductor material having the composition formula In x Al y Ga 1-x-y N (0≤x≤1, 0≤xy≤1, 0≤x+y≤1, selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN and AlInN), doped with a p-type dopant such as Mg, Zn, Ca, Sr or Ba.

[0264] Alternatively, the first conductive semiconductor layer 300-1 may be made of a P-GaN-based material. The P-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the P-type semiconductor layer may include Mg, Zn, Be, etc.

[0265] The second conductive semiconductor layer 300-3 is a semiconductor layer in which free electrons with negative charges move as charge carriers to generate a current.

[0266] The second conductive semiconductor layer 300-3 may be formed, for example, by adding an n-type semiconductor layer. The second conductive semiconductor layer 300-3 may be a semiconductor material having a composition formula of In x Al y Ga 1-x-y N (0≤x≤1, 0≤xy≤1, 0≤x+y≤1, selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN and AlInN, and doped with an n-type dopant such as Si, Ge or Sn.

[0267] Alternatively, the second conductive semiconductor layer 300-3 may also be made of an n-GaN-based material. The n-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, etc., and the impurities used to dope the n-type semiconductor layer 212c may include Si, Ge, Se, Te, C, etc.

[0268] Moreover, the present embodiment is not limited thereto, and the first conductive semiconductor layer 300-1 may include an n-type semiconductor layer, and the second conductive semiconductor layer 300-3 may include a p-type semiconductor layer.

[0269] The active layer 300-2 is a region where electrons and holes recombine, and when the electrons and holes recombine, the active layer 100-2 can transition to a lower energy level to produce light of the corresponding wavelength.

[0270] The active layer 300-2 can, for example, be made of a semiconductor material with the composition formula In x Al y Ga 1-x-y N (0x≤1, 0≤yx≤1, 0≤x+y≤1) and are formed in a single quantum well structure or an MQW structure.

[0271] Furthermore, the active layer 300-2 may include a quantum wire structure or a quantum dot structure.

[0272] The active layer 300-2 may be disposed on the first conductive semiconductor layer 300-1 and may comprise an MQW structure including a well layer and a barrier layer with a higher band gap than the well layer. The active layer 300-2 may, for example, comprise an MQW structure, such as InGaN / GaN.

[0273] Subsequently, with reference to Fig. 17B, ​​a region in which a first protrusion is formed is defined by selectively patterning the light-emitting layer part 300a' and removing a part of the light-emitting layer part 300a' in a region except for a region used as an active layer.

[0274] Next, with reference to Fig. 17C, a first electrode layer 314a made of a transparent conductive material such as ITO or IZO, which is used as a first electrode, is applied to the light-emitting layer part 300a'.

[0275] The first electrode layer 314a may be made of, but is not necessarily limited to, a transparent or translucent electrode material. The transparent or translucent electrode material may include one or more materials from the group consisting of ITO, IZO, ZnO, In2O3, IGO, and AZO.

[0276] Subsequently, with reference to Fig. 17D, by performing a patterning process using a masking process to selectively remove the first electrode layer 314a and the light-emitting layer part 300a' disposed under the first electrode layer 314a, the regions of the light-emitting element are separated, and the lower electrode 314 and the light-emitting layer 300a of the light-emitting element are formed.

[0277] When forming the light-emitting layer 300a, the first flat protrusion 300a-1 may also be formed simultaneously on the lower surface of the light-emitting layer 300a.

[0278] Next, with reference to Fig. 17E, a first portion of the passivation layer 316a is formed on the growth substrate 310, which includes the bottom electrode 314 and the light-emitting layer 300a. The first portion of the passivation layer 316a may be formed as a multilayer or single-layer film of an inorganic material.

[0279] The first part of the passivation layer 316a may be selected from any of SiO2, Si N 34 and a resin or an oxide containing at least one of the elements Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag and Al.

[0280] The inorganic material may, for example, be a metal oxide or metal nitride, and in particular the inorganic material may contain at least one of the following: SiO2, SiN x , SiON, Al2O3, TiO2, Ta2O5, HfO2, and ZrO2.

[0281] Subsequently, with reference to Fig. 17F, the first passivation layer 316, which delimits each of the light-emitting regions, is formed by selectively patterning the first part of the passivation layer 316a.

[0282] The first passivation layer 316 may be disposed on the side surfaces of the light-emitting layer 300a as well as on the side surfaces and the bottom surface of the lower electrode 314.

[0283] Subsequently, with reference to Fig. 17G, a metal layer 318a used as a reflecting mirror is formed on the entire surface of the growth substrate 210, including the first passivation layer 316 included on the separated region of the light-emitting element.

[0284] The metal layer 318a may be formed in a single layer or multiple layers of one or more of the following materials: Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, and Cu. In particular, a material with high light reflectivity may preferably be used as the material of the metal layer 318a. In the present exemplary embodiment, a case where aluminum (Al) is used as the material of the metal layer 318a is described, but the present disclosure is not limited thereto.

[0285] Next, with reference to Fig. 17H, the reflective layer 318 is formed on the side surfaces of the first passivation layer 316 by selectively etching the metal layer 318a through an etch-back process.

[0286] Subsequently, with reference to Fig. 17I, a second portion of the passivation layer 320a is formed on the growth substrate 310, which includes the reflective layer 318 and the first passivation layer 316. The second portion of the passivation layer 320a can be formed as a multilayer or single-layer film of an inorganic material.

[0287] The second part of the passivation layer 320a may be made of any of the following materials: SiO2, Si N 34 and a resin or an oxide containing at least one of the elements Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag and Al.

[0288] The inorganic material may, for example, be a metal oxide or metal nitride, and in particular the inorganic material may contain at least one of the following: SiO2, SiN x , SiON, Al2O3, TiO2, Ta2O5, HfO2, and ZrO2.

[0289] When the second part of the passivation layer 320a is formed, the second part of the passivation layer 320a may be made of a material that is identical to or different from that of the first part of the passivation layer 316a.

[0290] Next, with reference to Fig. 17J, the second passivation layer 320, which delimits each of the light-emitting regions, is formed by selectively patterning the second passivation layer part 320a.

[0291] When structuring the second passivation layer 320a, the second passivation layer part 320a, which is in contact with the lower electrode 314 and a surface of the growth substrate 310, may also be removed together so that parts of the lower electrode 314 and the growth substrate 310 can be exposed to the outside.

[0292] The reflective layer 318 may be arranged in a shape surrounded by the first passivation layer 316 and the second passivation layer 320. Furthermore, the first and second passivation layers 316 and 320 may be arranged to surround the side surfaces of the light-emitting layer 300a and the side surfaces and the top surface of the lower electrode 314. Furthermore, the reflective layer 318 may be arranged between the first and second passivation layers 316 and 320 and overlap the side surfaces of the light-emitting layer 300a.

[0293] The reflector 16 may include first and second passivation layers 316 and 320 surrounding the light-emitting layer 300a and the bottom electrode 314, and the reflective layer 318 disposed therebetween.

[0294] Subsequently, with reference to Fig. 17K, the pad structure 324 is formed in contact with the lower electrode 314 by depositing the metal material layer on the entire surface of the growth substrate 310, including the exposed part of the lower electrode 314 and the second passivation layer 320, and selectively patterning the metal material layer.

[0295] As in Fig. 17K, the pad structure 324 may be formed in a stacked structure of the first metal layer 324a, the second metal layer 324b, the third metal layer 324c, and the fourth metal layer 324d, or a single-layer structure formed of a single metal layer, which may be any of the above-mentioned metal layers, but is not necessarily limited thereto.

[0296] When the structure of the pad 324 is a stacked structure, the second and third metal layers 324b and 324c may be disposed between the first metal layer 324a and the fourth metal layer 324d. Although each of the first to fourth metal layers 324a to 324d may be made of any of gold (Au), aluminum (Al), and nickel (Ni), or an alloy thereof, and the first and fourth metal layers 324a and 324d may be made of a different metal than the second and third metal layers 324b and 324c, the present disclosure is not limited thereto. The second metal layer 324b may be made of a different metal than the first, third, and fourth metal layers 324a, 324c, and 324d. For example, the first and fourth metal layers 324a and 324d may contain gold (Au), the second metal layer 324b may contain aluminum (Al), and the third metal layer 324c may contain nickel (Ni).

[0297] However, the number of layers of the stacked structure of the pad structure 324 is not limited to one or four layers; the number of layers of the stacked structure of the pad structure 324 may be n (where n is an integer). For example, when the pad structure 324 has a stacked structure, the second, third, and fourth metal layers may be formed between the first metal layer and the fifth metal layer. Each of the first to fifth metal layers may be made of any one of Au, Al, and Ni or an alloy thereof, and at least one of the first to fifth metal layers may be made of a different metal than the other layers, but the present disclosure is not limited thereto.

[0298] Next, with reference to Fig. 17L, a sacrificial layer 326a is formed on the entire structure of the growth substrate 310, which includes the pad structure 324. Any insulating material, including SiO2, SiN, etc., can be selectively used as the sacrificial layer 326a.

[0299] Subsequently, with reference to Fig. 17M, the region of the light-emitting element is separated by selectively patterning the sacrificial layer 232a through the masking process, and at the same time, a contact hole 328h is formed, exposing a part of the pad structure 324.

[0300] With reference to Fig. 17N, the process of fabricating the light-emitting element on the growth substrate 310 is completed by forming a dummy insulating layer 330a on the growth substrate 310, which includes the sacrificial layer 326, to planarize the growth substrate 310. BCB or other insulating materials can be optionally used as the material for the dummy insulating layer 330a.

[0301] The following describes a process for arranging and bonding the part of the light-emitting element on the support substrate.

[0302] First, the support substrate 350 is provided, and a process of separating the light-emitting element from the growth substrate 310 is performed to transfer the light-emitting element to the support substrate 350.

[0303] The support substrate 350 may be made of polymer resin, glass, quartz, a resin film, a transparent substrate, and a transparent flexible polymer substrate.

[0304] With reference to Fig. 17O, a structure formed on the growth substrate 310 is placed and bonded to the support substrate 350. Although not shown in the drawing, to laminate the growth substrate 310 in an inverted state to the support substrate 350, an ultraviolet-reactive resin layer (not shown), which can be used as an adhesive layer, may be formed on the support substrate 350.

[0305] In this case, in the state of inversion of the growth substrate 310, a part of the dummy insulating layer 330a is arranged and bonded on the support substrate 350 to expose the growth substrate 310 to the outside.

[0306] Next, with reference to Fig. 17P, after the part of the growth substrate 310 that emits the brightness is in contact with the ultraviolet-reactive resin layer (not shown) of the support substrate 350, a laser is irradiated onto a boundary between the part of the light-emitting element and the growth substrate 310.

[0307] The laser emitted from the laser source after passing through the growth substrate 310 can separate the light-emitting element portion from the growth substrate 310. In this case, the light-emitting element portion can remain in contact with the ultraviolet-reactive resin layer (not shown) of the support substrate 350.

[0308] Subsequently, with reference to Fig. 17Q, after the growth substrate 310 is removed by laser radiation, a second electrode layer 352a is formed on the first and second passivation layers 316 and 320, including the light-emitting layer 300a, which is the exposed area of ​​the part of the light-emitting element, the area of ​​the reflective layer 318 arranged between the first and second passivation layers 316 and 320, the sacrificial layer 326, and the dummy insulating layer 330a.

[0309] The second electrode layer 352a may be made of, but is not necessarily limited to, a transparent or translucent electrode material. The transparent or translucent electrode material may include one or more materials from the group consisting of ITO, IZO, ZnO, In2O3, IGO, and AZO. In the present disclosure, an example of a case where ITO is used as the transparent electrode material is described.

[0310] Next, with reference to Fig. 17R, a second electrode 352 is formed on the light-emitting layer 300a by selectively patterning the second electrode layer 352a through the masking process. In this case, when patterning the second electrode layer 352a, upper portions of the first and second passivation layers 316 and 320, including the side surfaces of the light-emitting layer 300a and the second electrode layer 352a, an upper portion of the reflective layer 318 disposed between the first and second passivation layers 316 and 320, and upper portions of portions of the sacrificial layer 326 and the insulating layer 330a may be etched together and exposed to the outside.

[0311] In this case, the second flat protrusion 300a-2 may be formed on the upper surface of the light-emitting layer 300a, and stepped parts (not shown) may be formed on the side surfaces of the light-emitting layer 300a.

[0312] As described above, the light-emitting layer 300a, the first and second electrodes 314 and 352, and the reflective layer 318 disposed between the first and second passivation layers 316 and 320, surrounding the side surfaces and the bottom surfaces of the light-emitting layer 300a and the bottom electrode 314, which form the light-emitting element 300 (see Fig. 17T), are formed.

[0313] Subsequently, with reference to Fig. 17S, the part of the dummy insulating layer 330a disposed between the sacrificial layers 326 is selectively removed from the externally exposed areas by a dry etching process.

[0314] With reference to Fig. 17T, the light-emitting element 300 remains on the carrier substrate 350 by removing the remaining sacrificial layers 326 through the wet etching process.

[0315] As described above, the process of separating the light-emitting element 300 according to another exemplary embodiment of the present disclosure from the growth substrate 310 and bonding the light-emitting element 300 to the support substrate 350 is completed.

[0316] Next, in the display device according to an exemplary embodiment of the present specification, a process for transferring the light-emitting element formed on the support substrate to the substrate will be described.

[0317] Fig. 18A to 18G are process cross-sectional views for describing a process for manufacturing a pixel in the display device according to an exemplary embodiment of the present specification.

[0318] With reference to Fig. 18A, the pixel driving circuit 20 is formed on the substrate 110, and the buffer layer 121 covering the pixel driving circuit 20 is arranged on the substrate 110 including the pixel driving circuit 20.

[0319] The substrate 110 may be made of a flexible plastic. For example, the substrate 110 may be formed as a single layer or multiple layers of a material selected from the group consisting of, but not limited to, polyimide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, polyarylate, polysulfone, and a cyclic olefin copolymer. The substrate 110 may, for example, be a glass substrate.

[0320] The buffer layer 121 may be made of an inorganic insulating material such as SiN x or SiO2, wherein the inorganic insulating material is stacked in multiple layers, and an organic insulating material and an inorganic insulating material are used in such a manner that the organic insulating material and the inorganic insulating material are stacked in multiple layers.

[0321] The interconnect lines RT1 and RT2 may be arranged on the buffer layer 121. The interconnect 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 interconnect lines RT1 and RT2 may include a plurality of conductive patterns arranged on different layers with one or more insulating layers between them. The conductive patterns arranged on different layers may be electrically connected by contact holes penetrating the insulating layers formed in subsequent processes.

[0322] The interconnect lines RT1 and RT2 can be single- or multi-layer metal lines formed from materials selected from the group consisting of aluminum (Al), titanium (Ti), copper (Cu), molybdenum (Mo), tantalum (Ta), titanium nitride (TiN), and tantalum nitride (TaN). For example, the interconnect lines RT1 and RT2 can be metal lines stacked in a three-layer structure, such as Ti / Al / Ti or Mo / Al / Mo.

[0323] The first insulating layer 122 may be disposed on the buffer layer 121, which contains the connecting lines RT1 and RT2. The first insulating layer 122 may be made of an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide. For example, the first insulating layer 122 may include a single layer or multiple insulating layers of an inorganic insulating material, such as, but not limited to, silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide. For example, the first insulating layer 122 may be configured as a single layer or a multi-layer of silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide.For example, the first insulating layer 122 may be formed by inorganic films in a single layer or in multiple layers, for example, the inorganic film in a single layer may be made of silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide film, and inorganic films in multiple layers may be formed by alternately stacking at least one of one or more silicon oxide films, one or more silicon nitride films, one or more silicon oxynitride films, one or more aluminum oxide films, and one or more amorphous silicon (a-Si), but the present disclosure is not limited thereto.

[0324] Subsequently, the bank structure 130 can be formed on the first insulating layer 122. The bank structure 130 can be made of an organic insulating material such as, but is not limited to, photosensitive photoacrylic or photosensitive polyimide. The bank structure 130 can control a mounting position of the light-emitting element during the light-emitting element transfer process. The bank structure 130 can also be omitted.

[0325] Each of the bank structures 130 may be arranged under a light-emitting element 100 (see Fig. 10) or two light-emitting elements.

[0326] Subsequently, the first electrode 161 may be formed on the bank structure 130 and the first insulating layer 122.

[0327] The first electrode 161, the connecting portion 161a, the signal line TL, and / or the connecting lines RT1 and RT2 may include a single or multiple metal layers formed from materials selected from the group consisting of titanium (Ti), molybdenum (Mo), and aluminum (Al). The first electrode 161, the connecting portion 161a, the signal line TL, and / or the connecting line RT2 may be formed in a multilayer structure including the first layer ML1, the second layer ML2, the third layer ML3, and the fourth layer ML4.

[0328] 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 ITO or IZO, which adheres well to the solder structure 163 and is also corrosion and acid resistant.

[0329] 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.

[0330] In addition, the contact electrode (not shown, 162 in Fig. 10) is formed on the first insulating layer 122 in an area excluding the bank structure 130. In this case, the second contact electrode 162 can be formed from the same material as the first electrode 161 at the same time.

[0331] Subsequently, the solder structure 163 may be disposed on the first electrode 161. The solder structure 163 may be made of, but is not limited to, indium (In), tin (Sn), or an alloy thereof. In the light-emitting region, the pad structure 230 formed on the lower surface of the lower electrode 214 of the light-emitting element 100 may be in contact with an upper surface of the solder structure 163.

[0332] Subsequently, the second insulating layer 133 is formed on the solder structure 163, the first electrode 161, the bank structure 130 and the first insulating layer 122.

[0333] The second insulating layer 133 may be made of an organic insulating material, such as, but not limited to, photosensitive photoacrylic or photosensitive polyimide. The first insulating layer 122 may, for example, include a single or multiple insulating layers of an inorganic insulating material, such as, but not limited to, silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide. For example, the first insulating layer 122 may be configured as a single layer or a multi-layer of silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide.For example, the first insulating layer 122 may be formed by an inorganic film in a single layer or in multiple layers, for example, the inorganic film in a single layer may be made of silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide film, and inorganic films in multiple layers may be formed by alternately stacking at least one of one or more silicon oxide films, one or more silicon nitride films, one or more silicon oxynitride films, one or more aluminum oxide films, and one or more amorphous silicon (a-Si), but the present disclosure is not limited thereto.

[0334] Subsequently, the second insulating layer 133 is selectively etched through the photolithography patterning process to expose the upper portions of the solder structure 163 and / or the first electrode 161. During the patterning of the second insulating layer 133, contact holes (not shown) may be formed that expose the upper portions of the solder structure 163 and / or the first electrode 161.

[0335] The upper part of the solder structure 163 may be exposed by protruding upward from the second insulating layer 133 or exposed in the contact hole of the second insulating layer 133.

[0336] Next, although not shown in the drawing, a connecting member (not shown) for transferring the light-emitting element 100 may be formed on the second insulating layer 133 on the substrate 110. However, the present disclosure is not necessarily limited thereto.

[0337] This is followed by, with reference to Fig. 18B, in order to transfer the light-emitting element 100 to the second insulating layer 133, the substrate separation process of separating the light-emitting element 100 from the support substrate 250 (see Fig. 14T). The substrate separation process may use LLO, chemical lift-off (CLO), a method of destroying the insulating layer 236 by applying pressure with a stamp, or the like.

[0338] Through the process of substrate separation, the light-emitting element 100 can be separated from the carrier substrate 250 (see Fig. 14T).

[0339] Next, the pad structure 230 formed on the lower surface of the separated light-emitting element 100 may be in contact with the solder structure 163 and the second insulating layer 133 disposed above the bank structure 130 on the substrate 110, or may be disposed on the solder structure 163 and the first electrode 161.

[0340] The light-emitting element 100 may be fixed by a connecting member (not shown) and / or the first electrode 161 and the solder structure 163.

[0341] The lower electrode 214 of each of the light-emitting elements 100 may be electrically connected to the anode voltage output terminal of the pixel drive circuit 20 via the solder pattern 163, the first electrode 161, and at least one conductive pattern through the pad pattern 230 formed on the lower surface of the lower electrode 214. The upper electrode 252 of each of the light-emitting elements 100 may be electrically connected to the output terminal of the pixel drive circuit 20 via the second electrode 170, the contact electrode 162, and at least one pattern.

[0342] Next, with reference to Fig. 18C, the first insulating interlayer 141 is formed on the light-emitting element 100 and the second insulating layer 133 is formed on the substrate 110.

[0343] The first insulating interlayer 141 may cover the plurality of light-emitting elements 100 and the bank structures 130. The first insulating interlayer 141 may cover the space between the plurality of light-emitting elements 100 and the space between the bank structures 130. The first insulating interlayers 141 may extend in the first direction X and may be spaced apart from each other in the second direction Y to separate the rows of pixels.

[0344] The light emitted by the plurality of light-emitting elements 100 can be scattered by the fine metal particles dispersed in the first insulating interlayer 141 and emitted to the outside.

[0345] The first insulating interlayer 141 may contain an organic insulating material in which fine metal particles, such as titanium dioxide particles, are dispersed.

[0346] Furthermore, the first insulating interlayer 141 may be formed by selecting a material with excellent planarization properties from among organic insulating materials or inorganic insulating materials containing an oxide film or a nitride film. However, the present disclosure is not necessarily limited thereto.

[0347] Since the first insulating interlayer 141 can be formed from a relatively inexpensive material, such as an inorganic insulating material containing an oxide film or a nitride film, the first insulating interlayer 141 can replace the existing sidewall diffuser made of an expensive material, thereby reducing the cost of the manufacturing process.

[0348] Although not shown in the drawing, the second insulating intermediate layer (not shown, 142 in Fig. 4) surrounding the edge of the first insulating interlayer 141. The second insulating interlayer 142 may be made of an organic insulating material.

[0349] The second insulating intermediate layer 142 can be deposited together with the first insulating intermediate layer 141 on the second insulating layer (not shown, 133 in Fig. 4). The first insulating interlayer 141 and the second insulating interlayer 142 may be made of the same material or different materials. However, the present disclosure is not necessarily limited thereto.

[0350] Subsequently, with reference to Fig. 18D, the contact hole 141h exposing the upper electrode 252 of the light-emitting element 100 may be formed by selectively removing the first insulating interlayer 141 through the masking process.

[0351] Next, with reference to Fig. 18E, the second electrode 170 is formed in contact with the upper electrode 252 of the light-emitting element 100 by forming the second electrode layer (not shown) on the first insulating interlayer 141 containing the contact hole 141h and patterning the second electrode layer by the photolithographic process. The second electrode 170 may generally be connected to the plurality of pixels (not shown, PXLs in Fig. 2). The second electrode 170 may be a thin electrode through which light is transmitted. The second electrode 170 may be made of a transparent electrode material, such as ITO, but is not necessarily limited thereto.

[0352] The second electrodes 170 may each overlap the first insulating interlayer 141, and some of the second electrodes 170 may cover the outer surface of the first insulating interlayer 141.

[0353] The second electrode 170 may be disposed on the first insulating interlayer 141 and commonly connected to all pixels PXL. The second electrode 270 may be a thin metal electrode through which light is transmitted. The first electrode 161, the second electrode 170, and the black matrix 180 may be stacked in the non-emitting region of the pixel area. The second electrode 170 may be made of a transparent electrode material, such as ITO, but is not necessarily limited thereto.

[0354] Next, with reference to Fig. 18F, the black matrix 180 is formed on the second electrode 170. The black matrix 180 may be made of an organic insulating material to which a black pigment is added.

[0355] Subsequently, with reference to Fig. 18G, the cover layer 190 is formed on the black matrix 180 and the second electrode 170. The cover layer 190 may be made of an organic insulating material covering the black matrix 180 and the second electrode 170.

[0356] An insulating layer, the same as the first insulating interlayer 141, may be formed flat between the cap layer 190 and the second electrode 170. In this case, the insulating layer made of an organic insulating material may cover the second electrode 170 with a smaller thickness than the first insulating interlayer 141.

[0357] As described above, when transferring the light-emitting element 100 to the substrate 110, the lower electrode 214 is connected to the pixel electrode (not shown) via the pad structure 230, so that a positive voltage is applied to the lower electrode 214 via the pixel electrode and a negative voltage is applied to the upper electrode 252 via the second electrode 170. Therefore, a current flows between the pixel electrode (not shown) and the second electrode 170 due to the movement of electrons of the second conductive semiconductor layer and the flow of holes of the first conductive semiconductor layer.

[0358] Fig. 19 is a cross-sectional view schematically showing a state in which light is reflected in and emitted from the light-emitting element of the display device according to an exemplary embodiment of the present specification.

[0359] Fig. 20 is a cross-sectional view schematically showing a state in which light is reflected in and emitted from the light-emitting element of the display device according to another exemplary embodiment of the present specification.

[0360] With reference to Fig. 19, it can be seen that the light generated in the light-emitting device 100 of the display device according to an exemplary embodiment of the present description is reflected by the reflective layer 218 of the reflector 16 arranged on the side surfaces and the bottom surface of the light-emitting element 100 and emitted upward, thereby increasing the luminous efficiency.

[0361] Since the reflective layer 218 is disposed between the first and second passivation layers 216 and 220 to surround the side surfaces and the bottom surface of the light-emitting element 100, it is possible that the light generated inside the light-emitting element 100 can be reflected by the reflective layer 218 and effectively emitted upward from the light-emitting element 100.

[0362] With reference to Fig. 20, it can be seen that the light generated in the light-emitting element 300 of the display device according to another exemplary embodiment of the present description is reflected by the reflective layer 318 of the reflector 16 arranged on the side surfaces in the light-emitting element 300 and emitted upward, thereby increasing the luminous efficiency.

[0363] Since the reflective layer 318 is disposed between the first and second passivation layers 316 and 320 to surround the side surfaces of the light-emitting element 300, it is possible for the light generated inside the light-emitting element 300 to be reflected by the reflective layer 318 and effectively emitted upward from the light-emitting element 300.

[0364] With reference to Fig. 19 and Fig. 20, at least a portion of the light generated by the light-emitting layers 100a and 300a passes through the first electrodes 214 and 314, is reflected by the reflective layers 218 and 318, passes through the first electrodes 214 and 314, the light-emitting layers 100a and 300a, and the second electrodes 252 and 352, and is emitted to the outside.

[0365] In addition, since the process of patterning a part of the layer arranged under the light-emitting element is required to form the shape of the mirror, conventionally the process tolerance is usually formed low.

[0366] However, in the present disclosure, the process of forming the reflective mirror under the light-emitting elements 100 and 300 is omitted, the first and second passivation layers surrounding the outer surface of the light-emitting element are disposed on the side surfaces of the light-emitting element, and the reflective layer replaced by the reflective mirror is formed between the first and second passivation layers, and thus it is possible to solve the conventional problem that the process margin becomes narrow.

[0367] In an exemplary embodiment of the present description, by arranging the reflective layer inside the light-emitting element to increase the luminous efficacy inside the light-emitting element, it is possible to increase the luminous efficacy even with low power consumption and thus to increase the luminous efficacy.

[0368] Moreover, in an exemplary embodiment of the present specification, it is possible to simplify a manufacturing process because a process of patterning the reflective layer inside the light-emitting element to form the reflective mirror or the like can be omitted.

[0369] In addition, since in an exemplary embodiment of the present specification the reflective layer is arranged in the light-emitting element to increase the luminous efficiency even without the sidewall diffuser made of an expensive material to increase the luminous efficiency, it is possible to reduce the cost of the manufacturing process.

[0370] In the present specification, since the reflective layer is formed in the light-emitting element to enable direct reflection of light in the light-emitting element, it is possible to increase the luminous efficiency.

[0371] Since a process for forming the reflecting mirror over a structure can be omitted in the present description, it is possible to simplify the process and fundamentally avoid process tolerance errors.

[0372] In the present specification, since the reflective layer is disposed inside the light-emitting element to increase the luminous efficiency, the sidewall diffuser made of an expensive material with excellent luminous efficiency does not need to be used, and thus it is possible to reduce the process material.

[0373] Moreover, in an exemplary embodiment of the present specification, it is possible to simplify a manufacturing process because a process of patterning the reflective layer under the light-emitting element to form the reflective mirror or the like can be omitted.

[0374] The display device according to various exemplary embodiments of the present disclosure may be described as follows.

[0375] A display device according to an exemplary embodiment of the present description may include a first electrode, a second electrode, a light-emitting layer disposed between the first electrode and the second electrode, and a reflector covering side surfaces of the light-emitting layer and at least a part of the side surfaces of the first electrode, wherein the reflector includes a first insulating layer, a second insulating layer, and a metal layer disposed between the first insulating layer and the second insulating layer.

[0376] According to the display device according to one or more exemplary embodiments of the present disclosure, the metal layer may be disposed between the first insulating layer and the second insulating layer to overlap the side surfaces and a bottom surface of the light-emitting layer or to overlap the side surfaces of the light-emitting layer.

[0377] According to the display device according to one or more embodiments of the present disclosure, the light-emitting layer may include a lower surface on which the first electrode is disposed, an upper surface on which the second electrode is disposed; and the side surfaces between the lower surface and the upper surface, wherein the lower and upper surfaces of the light-emitting layer include first and second flat protrusions on which the first and second electrodes are disposed, and stepped parts arranged at the edges of the first and second flat protrusions, wherein the stepped parts have a lower height than the first and second flat protrusions, and the reflector is arranged on at least a part of the side surfaces of the light-emitting layer below the stepped part.

[0378] According to the display device according to one or more exemplary embodiments of the present disclosure, the first electrode is arranged to cover a part of the side surfaces of the light-emitting layer and a bottom surface of the light-emitting layer.

[0379] According to the display device according to one or more embodiments of the present disclosure, the reflector is arranged to cover side surfaces of the first electrode and a part of a bottom surface of the first electrode.

[0380] According to the display device according to one or more exemplary embodiments of the present disclosure, the display device further comprises a plurality of protruding bank structures arranged in sub-pixels of the display device.

[0381] According to the display device according to one or more exemplary embodiments of the present disclosure, the display device further includes a pad structure arranged on a lower surface of the first electrode and on the protruding bank structure.

[0382] According to the display device according to one or more exemplary embodiments of the present disclosure, the pad structure is formed as a metal layer or a stacked structure including at least two metal layers, and when the pad structure has a stacked structure including the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers.

[0383] According to the display device according to one or more exemplary embodiments of the present disclosure, a lower surface of the light-emitting layer on which the first electrode of the light-emitting element may be disposed and the upper surface of the light-emitting layer on which the second electrode is disposed have smaller widths than the side surfaces between the upper surface and the lower surface of the light-emitting layer.

[0384] A display device according to one or more exemplary embodiments of the present disclosure may include a display panel on which a plurality of subpixels and lines connected to the subpixels are arranged, and a pixel driving circuit configured to drive the subpixels, wherein the display panel further includes a plurality of protruding bank structures arranged in the subpixels and a light-emitting element arranged in each of the bank structures, the light-emitting element including a first electrode, a second electrode, a light-emitting layer arranged between the first electrode and the second electrode, and a reflector covering side surfaces of the light-emitting layer and at least a part of the side surfaces of the first electrode, and the reflector including a first insulating layer,a second insulating layer and a metal layer arranged between the first insulating layer and the second insulating layer.,

[0385] According to the display device according to one or more exemplary embodiments of the present disclosure, the first electrode is arranged to cover a part of the side surfaces of the light-emitting layer and a bottom surface of the light-emitting layer.

[0386] According to the display device according to one or more embodiments of the present disclosure, the reflector is arranged to cover side surfaces of the first electrode and a part of a bottom surface of the first electrode.

[0387] According to the display device according to one or more exemplary embodiments of the present disclosure, the display panel further includes a pad structure arranged on a lower surface of the first electrode and on the protruding bank structure.

[0388] According to the display device according to one or more exemplary embodiments of the present disclosure, the pad structure is formed as a metal layer or a stacked structure including at least two metal layers, and when the pad structure has a stacked structure including the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers.

[0389] According to a display device according to one or more exemplary embodiments of the present disclosure, the metal layer may be disposed between the first insulating layer and the second insulating layer to overlap the side surfaces and a bottom surface of the light-emitting element or to overlap the side surfaces of the light-emitting element.

[0390] According to the display device according to one or more embodiments of the present disclosure, the first and second insulating layers may be made of any inorganic or organic insulating material or of an oxide containing at least one of Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag, Al, Hf, Zr, and Ta.

[0391] According to the display device according to one or more exemplary embodiments of the present disclosure, the light-emitting layer may include a lower surface on which the first electrode is arranged, an upper surface on which the second electrode is arranged, and the side surfaces between the lower surface and the upper surface, the lower and upper surfaces of the light-emitting layer may include first and second protrusions on which the first and second electrodes are arranged, and stepped parts arranged at the edges of the first and second protrusions, the stepped parts having a lower height than the first and second protrusions, and the reflector is arranged on at least a part of the side surfaces of the light-emitting element below the stepped part.

[0392] According to the display device according to one or more exemplary embodiments of the present disclosure, a lower surface of the light-emitting layer on which the first electrode may be disposed and the upper surface of the light-emitting layer on which the second electrode is disposed have a smaller width than the side surfaces between the upper surface and the lower surface of the light-emitting layer.

[0393] According to the display device according to one or more exemplary embodiments of the present disclosure, an area of ​​the light-emitting element is less than or equal to an area of ​​the bank structure.

[0394] According to the display device according to one or more exemplary embodiments of the present disclosure, the light-emitting element may be connected to an electrode line and a soldering pattern arranged on the bank structure through a pad structure arranged on a lower surface of the first electrode.

[0395] According to the display device according to one or more exemplary embodiments of the present disclosure, the area of ​​the light-emitting element may be less than or equal to the area of ​​the electrode line.

[0396] According to the display device according to one or more embodiments of the present disclosure, an insulating interlayer may be disposed on the entire surface of a substrate including the light-emitting element.

[0397] According to the display device according to one or more embodiments of the present disclosure, the insulating interlayer may have a stacked structure of one or more organic insulating materials and an inorganic insulating material including an oxide film or a nitride film.

[0398] A method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure may include: forming a light-emitting layer on a substrate, forming a first electrode layer under the light-emitting layer, forming a first insulating layer and a second insulating layer on side surfaces of the light-emitting layer and at least a part of the side surfaces of the first electrode, forming a reflective layer between the first insulating layer and the second insulating layer, and forming a second electrode on the light-emitting layer.

[0399] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the first electrode layer is arranged to cover a part of the side surfaces of the light-emitting layer and a bottom surface of the light-emitting layer.

[0400] According to the method for manufacturing a display device according to one or more embodiments of the present disclosure, the reflective layer is arranged to cover side surfaces of the first electrode layer and a part of a bottom surface of the first electrode layer.

[0401] According to the method of manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the method further comprises forming a plurality of protruding bank structures on the substrate.

[0402] According to the method of manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the method further comprises forming a pad structure between a lower surface of the first electrode layer and the protruding bank structure.

[0403] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the pad structure is formed as one metal layer or a stacked structure including at least two metal layers, and when the pad structure has a stacked structure including the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers.

[0404] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the reflective layer may be formed to overlap the side surfaces of the light-emitting layer and the side surfaces and a bottom surface of the first electrode, or may be formed to overlap the side surfaces of the light-emitting layer and the side surfaces of the first electrode.

[0405] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, forming the reflective layer may include forming the first insulating layer on the light-emitting layer and the first electrode, forming a metal layer on the first insulating layer, exposing a part of the first electrode by patterning the metal layer and the first insulating layer, and forming the second insulating layer on the patterned metal layer and the exposed first electrode, and forming the reflective layer between the first insulating layer and the second insulating layer.

[0406] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, forming the reflective layer may include forming the first insulating layer on the light-emitting layer and the first electrode layer (e.g., the first electrode), forming a metal layer on the first insulating layer, patterning the metal layer and the first insulating layer and forming the reflective layer on the side surfaces of the light-emitting layer and the first electrode, and forming the second insulating layer on the first insulating layer formed on the reflective layer and the side surfaces and a bottom surface of the first electrode layer (e.g., the first electrode).

[0407] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the metal layer may be patterned by an etch-back process to form the reflective layer between the first insulating layer and the second insulating layer formed on the side surfaces of the light-emitting layer and the first electrode layer (e.g., the first electrode).

[0408] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, a part of the light-emitting layer under both sides of the second electrode layer (e.g., the second electrode) is removed.

[0409] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, a protrusion may be formed on an upper surface of the light-emitting layer on which the second electrode is formed by removing a part of the upper surface of the light-emitting layer, and stepped parts are formed on side surfaces of the protrusion of the light-emitting layer.

[0410] A method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure may include forming a display panel on which a plurality of subpixels and lines connected to the subpixels are arranged, and forming a pixel drive circuit configured to drive the subpixels, wherein forming the display panel further comprises forming a plurality of protruding bank structures arranged in the subpixels and forming a light-emitting element arranged in each of the bank structures, forming the light-emitting element comprises forming a first electrode and a second electrode, forming a light-emitting layer arranged between the first electrode and the second electrode, and forming a reflector,the side surfaces of the light-emitting layer and at least a part of the side surfaces of the first electrode, and forming the reflector includes forming a first insulating layer and a second insulating layer on side surfaces of the light-emitting element and forming a metal layer between the first insulating layer and the second insulating layer.

[0411] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the first electrode is arranged to cover a part of the side surfaces of the light-emitting layer and a bottom surface of the light-emitting layer.

[0412] According to the method of manufacturing a display device according to one or more embodiments of the present disclosure, the reflector is arranged to cover side surfaces of the first electrode and a part of a bottom surface of the first electrode.

[0413] According to the method of manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the method further comprises forming a pad structure between a bottom surface of the first electrode and the protruding bank structure.

[0414] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the pad structure is formed as one metal layer or a stacked structure including at least two metal layers, and when the pad structure has a stacked structure including the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers.

[0415] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the metal layer may be disposed between the first insulating layer and the second insulating layer to overlap the side surfaces and a bottom surface of the light-emitting element or to overlap the side surfaces of the light-emitting element.

[0416] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, the light-emitting element may include a lower surface of the light-emitting layer on which the first electrode is disposed, an upper surface of the light-emitting layer on which the second electrode is disposed, and the side surfaces of the light-emitting layer between the lower surface and the upper surface, the lower and upper surfaces of the light-emitting layer may include first and second flat protrusions on which the second electrode is disposed, and stepped parts disposed at the edges of the first and second flat protrusions,wherein the stepped parts have a lower height than the first and second flat projections, and the metal layers are arranged on at least a part of the side surfaces of the light-emitting element below the stepped parts.

[0417] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, a lower surface of the light-emitting layer on which the first electrode of the light-emitting element may be disposed and the upper surface of the light-emitting layer on which the second electrode is disposed have a smaller width than the side surfaces between the upper surface and the lower surface of the light-emitting layer.

[0418] According to the method of manufacturing a display device according to one or more exemplary embodiments of the present disclosure, an area of ​​the light-emitting element may be less than or equal to an area of ​​the bank structure.

[0419] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, it may further include forming a pad structure on a lower surface of the first electrode and forming an electrode line and a solder structure to which the light-emitting element is connected through the pad structure on the bank structure.

[0420] According to the method for manufacturing a display device according to one or more exemplary embodiments of the present disclosure, it may further include forming an insulating interlayer on the substrate including the light-emitting element.

[0421] A method of manufacturing a display device according to one or more exemplary embodiments of the present disclosure, wherein the insulating interlayer may have a stacked structure of any one or more organic insulating materials and inorganic insulating materials including an oxide film or a nitride film.

[0422] The effects of the present description are not limited to the effects described above, and other effects not mentioned can be clearly understood by those skilled in the art from the above detailed description.

[0423] Since the content of the description described in the above-described problems to be solved, the means for solving the problems and the effects does not specify the essential features of the claims, the scope of the claims is not limited by the contents described in the content of the description.

[0424] Although exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not necessarily limited to the exemplary embodiments, and various changes may be made without departing from the present disclosure. Therefore, the embodiments disclosed in the present disclosure are not intended to limit the present disclosure but to describe the same, and the scope of the present disclosure is not limited by these embodiments. It should therefore be understood that the exemplary embodiments described above are illustrative and non-restrictive in all respects. 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 2023-0104258

[0001]

Claims

[1] A display device (10) comprising a light-emitting element (100, 300), the light-emitting element (100, 300) comprising: a first electrode (161); a second electrode (170); a light-emitting layer (100a, 300a) arranged between the first electrode (161) and the second electrode (170); and a reflector (16, 36) covering side surfaces of the light-emitting layer (100a, 300a) and at least part of the side surfaces of the first electrode (161), wherein the reflector (16, 36) contains: a first insulating layer (216, 316); a second insulating layer (220, 320); and a metal layer (218, 318) disposed between the first insulating layer (216, 316) and the second insulating layer (220, 320). [2] The display device (10) according to claim 1, wherein the metal layer (218, 318) is arranged between the first insulating layer (216, 316) and the second insulating layer (220, 320) so as to overlap the side surfaces and a bottom surface of the light-emitting layer (100a, 300a) or to overlap the side surfaces of the light-emitting layer (100a, 300a). [3] The display device (10) according to claim 1 or 2, wherein the light-emitting layer (100a, 300a) contains: a lower surface on which the first electrode (161) is arranged; an upper surface on which the second electrode (170) is arranged; and the side surfaces between the lower surface and the upper surface, wherein the lower surface and upper surface of the light-emitting layer (100a, 300a) contain: a first flat projection on which the first electrode (161) is arranged, and a second flat projection on which the second electrode (170) is arranged; and stepped parts arranged at the edges of the first and second flat projections, wherein the stepped portions have a lower height than each of the first and second flat projections, and the reflector (16, 36) is arranged on at least a part of the side surfaces of the light-emitting layer (100a, 300a) below the stepped part. [4] The display device (10) according to any one of claims 1 to 3, wherein a lower surface of the light-emitting layer (100a, 300a) on which the first electrode (161) of the light-emitting element (100, 300) is disposed and the upper surface of the light-emitting layer (100a, 300a) on which the second electrode (170) is disposed have smaller widths than the side surfaces between the upper surface and the lower surface of the light-emitting layer (100a, 300a). [5] The display device (10) according to any one of claims 1 to 4, wherein the first electrode (161) is arranged to cover a part of the side surfaces of the light-emitting layer (100a, 300a) and a bottom surface of the light-emitting layer (100a, 300a). [6] The display device (10) according to claim 5, wherein the reflector (16, 36) is arranged to cover side surfaces of the first electrode (161) and a part of a lower surface of the first electrode (161). [7] The display device (10) according to any one of claims 1 to 6, wherein the display device (10) further comprises a plurality of projecting bank structures (130) arranged in sub-pixels of the display device (10). [8] The display device (10) according to claim 7, wherein the display device (10) further comprises a pad structure (230, 324) arranged on a lower surface of the first electrode (161) and on the protruding bank structure (130). [9] The display device (10) according to claim 8, wherein the pad structure (230, 324) is formed as a metal layer or a stacked structure with at least two metal layers, and wherein, when the pad structure (230, 324) has a stacked structure with the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers. [10] A display device (10) comprising: a display panel on which a plurality of sub-pixels and lines connected to the sub-pixels are arranged; and a pixel control circuit configured to control the sub-pixels, The display panel also contains: a plurality of protruding bank structures (130) arranged in the sub-pixels; and a light-emitting element (100, 300) arranged in each of the bank structures (130), wherein the light-emitting element (100, 300) contains: a first electrode (161); a second electrode (170); a light-emitting layer (100a, 300a) arranged between the first electrode (161) and the second electrode (170); and a reflector (16, 36) covering side surfaces of the light-emitting layer (100a, 300a) and at least a part of the side surfaces of the first electrode (161), and wherein the reflector (16, 36) contains: a first insulating layer (216, 316); a second insulating layer (220, 320); and a metal layer (218, 318) disposed between the first insulating layer (216, 316) and the second insulating layer (220, 320). [11] The display device (10) according to claim 10, wherein the first electrode (161) is arranged to cover a part of the side surfaces of the light-emitting layer (100a, 300a) and a bottom surface of the light-emitting layer (100a, 300a). [12] The display device (10) according to claim 11, wherein the reflector (16, 36) is arranged to cover side surfaces of the first electrode (161) and a part of a lower surface of the first electrode (161). [13] The display device (10) according to any one of claims 10 to 12, wherein the display panel further comprises a pad structure (230, 324) arranged on a lower surface of the first electrode (161) and on the protruding bank structure (130). [14] The display device (10) of claim 13, wherein the pad structure (230, 324) is formed as a metal layer or a stacked structure with at least two metal layers, and wherein, when the pad structure (230, 324) has a stacked structure with the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers. [15] The display device (10) according to any one of claims 10 to 14, wherein the metal layer (218, 318) is disposed between the first insulating layer (216, 316) and the second insulating layer (220, 320) so as to overlap side surfaces and a bottom surface of the light-emitting element (100, 300) or to overlap the side surfaces of the light-emitting element (100, 300). [16] The display device (10) according to any one of claims 10 to 15, wherein the first and second insulating layers (122, 133) are made of any of an inorganic insulating material or an organic insulating material or an oxide including at least one of Ni, Ti, Pt, Pd, Cu, CuW, Mo, MoW, Ag, Al, Hf, Zr and Ta. [17] The display device (10) according to any one of claims 10 to 16, wherein the light-emitting layer (100a, 300a) contains: a lower surface on which the first electrode (161) is arranged; an upper surface on which the second electrode (170) is arranged; and the side surfaces between the lower surface and the upper surface, wherein the lower surface and upper surface of the light-emitting layer (100a, 300a) contain: a first projection on which the first electrode (161) is arranged, and a second projection on which the second electrode (170) is arranged; and stepped parts arranged at the edges of the first and second projections, wherein the stepped parts have a lower height than each of the first and second projections, and the reflector (16, 36) is arranged on at least a part of the side surfaces of the light-emitting element (100, 300) below the stepped part. [18] The display device (10) according to any one of claims 10 to 17, wherein a lower surface of the light-emitting layer (100a, 300a) on which the first electrode (161) is arranged and the upper surface of the light-emitting layer (100a, 300a) on which the second electrode (170) is arranged have smaller widths than the side surfaces between the upper surface and the lower surface of the light-emitting layer (100a, 300a). [19] The display device (10) according to any one of claims 10 to 18, wherein an area of the light-emitting element (100, 300) is less than or equal to an area of the bank structure (130). [20] The display device (10) according to any one of claims 10 to 19, wherein the light-emitting element (100, 300) is connected to an electrode lead and a solder pattern disposed on the bench structure (130) through a pad structure (230, 324) disposed on a lower surface of the first electrode (161). [21] The display device (10) according to claim 19 or 20, wherein the area of the light-emitting element (100, 300) is less than or equal to an area of the electrode line. [22] The display device (10) according to any one of claims 10 to 21, wherein an insulating interlayer is disposed on an entire surface of a substrate (110, 210) containing the light-emitting element (100, 300). [23] The display device (10) according to claim 22, wherein the insulating interlayer has a stacked structure of any one or more of an organic insulating material and an inorganic insulating material including an oxide film or a nitride film. [24] A method for manufacturing a display device (10) having a light-emitting element (100, 300), comprising: Forming a light-emitting layer (100a, 300a) on a substrate (110, 210); Forming a first electrode layer (114a) under the light-emitting layer (100a, 300a); Forming a first insulating layer (216, 316) and a second insulating layer (220, 320) on side surfaces of the light-emitting layer (100a, 300a) and at least a part of the side surfaces of the first electrode layer (114a); Forming a reflective layer (218, 318) between the first insulating layer (216, 316) and the second insulating layer (220, 320); and Forming a second electrode layer (352a) on the light-emitting layer (100a, 300a). [25] The method according to claim 24, wherein the first electrode layer (114a) is arranged to cover a part of the side surfaces of the light-emitting layer (100a, 300a) and a bottom surface of the light-emitting layer (100a, 300a). [26] The method according to claim 25, wherein the reflective layer (218, 318) is arranged to cover side surfaces of the first electrode layer (114a) and a part of a bottom surface of the first electrode layer (114a). [27] The method of any one of claims 24 to 26, further comprising forming a plurality of protruding bank structures (130) on the substrate (110, 210). [28] The method of claim 27, further comprising forming a pad structure (230, 324) between a bottom surface of the first electrode layer (114a) and the protruding bank structure (130). [29] The method of claim 28, wherein the pad structure (230, 324) is formed as a metal layer or a stacked structure with at least two metal layers, and wherein, when the pad structure (230, 324) has a stacked structure with the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers. [30] The method according to any one of claims 24 to 29, wherein the reflective layer (218, 318) is formed so as to overlap the side surfaces of the light-emitting layer (100a, 300a) and the side surfaces and a lower surface of the first electrode layer (114a) or is formed so as to overlap the side surfaces of the light-emitting layer (100a, 300a) and the side surfaces of the first electrode layer (114a). [31] The method of any one of claims 24 to 30, wherein forming the reflective layer (218, 318) comprises: Forming the first insulating layer (216, 316) on the light-emitting layer (100a, 300a) and the first electrode layer (114a); Forming a metal layer (218a) on the first insulating layer (216, 316); Exposing a portion of the first electrode layer (114a) by structuring the metal layer (218a) and the first insulating layer (216, 316); and Forming the second insulating layer (220, 320) on the patterned metal layer (218a) and the exposed first electrode layer (114a) and forming the reflective layer (218, 318) between the first insulating layer (216, 316) and the second insulating layer (220, 320). [32] The method of any one of claims 24 to 31, wherein forming the reflective layer (218, 318) comprises: Forming the first insulating layer (216, 316) on the light-emitting layer (100a, 300a) and the first electrode layer (114a); Forming a metal layer (218a) on the first insulating layer (216, 316); Structuring the metal layer (218a) and the first insulating layer (216, 316) and forming the reflective layer (218, 318) on the side surfaces of the light-emitting layer (100a, 300a) and the first electrode layer (114a); and Forming the second insulating layer (220, 320) on the first insulating layer (216, 316) formed on the reflective layer (218, 318) and the side surfaces and a bottom surface of the first electrode layer (114a). [33] The method according to claim 32, wherein the metal layer (218a) is patterned by an etch-back process to form the reflective layer (218, 318) between the first insulating layer (216, 316) and the second insulating layer (220, 320) formed on the side surfaces of the light-emitting layer (100a, 300a) and the first electrode layer (114a). [34] The method of any one of claims 24 to 33, further comprising removing a portion of the light-emitting layer (100a, 300a) under both sides of the second electrode layer (352a). [35] The method according to claim 34, wherein a protrusion is formed on an upper surface of the light-emitting layer (100a, 300a), on which the second electrode layer (352a) is formed by removing a part of the upper surface of the light-emitting layer (100a, 300a), and stepped parts are formed on side surfaces of the protrusion of the light-emitting layer (100a, 300a). [36] A method for manufacturing a display device (10), comprising: Forming a display panel on which a plurality of sub-pixels and lines connected to the sub-pixels are arranged; and Forming a pixel drive circuit configured to drive the sub-pixels, wherein forming the display panel further includes: Forming a plurality of protruding bank structures (130) arranged in the sub-pixels; and Forming a light-emitting element (100, 300) arranged in each of the bank structures (130), wherein forming the light-emitting element (100, 300) comprises: Forming a first electrode (161) and a second electrode (170); Forming a light-emitting layer (100a, 300a) arranged between the first electrode (161) and the second electrode (170); and Forming a reflector (16, 36) covering side surfaces of the light-emitting layer (100a, 300a) and at least a part of the side surfaces of the first electrode (161), and wherein forming the reflector (16, 36) comprises: Forming a first insulating layer (216, 316) and a second insulating layer (220, 320) on side surfaces of the light-emitting element (100, 300); and Forming a metal layer (218a) between the first insulating layer (216, 316) and the second insulating layer (220, 320). [37] The method according to claim 36, wherein the first electrode (161) is arranged to cover a part of the side surfaces of the light-emitting layer (100a, 300a) and a bottom surface of the light-emitting layer (100a, 300a). [38] The method according to claim 37, wherein the reflector (16, 36) is arranged to cover side surfaces of the first electrode (161) and a part of a lower surface of the first electrode (161). [39] The method of any one of claims 36 to 38, further comprising forming a pad structure (230, 324) between a bottom surface of the first electrode (161) and the protruding bank structure (130). [40] The method of claim 39, wherein the pad structure (230, 324) is formed as a metal layer or a stacked structure having at least two metal layers, and wherein, when the pad structure (230, 324) comprises a stacked structure having the at least two metal layers, at least one metal layer is made of a different metal than the other metal layers. [41] The method according to any one of claims 36 to 40, wherein the metal layer (218a) is disposed between the first insulating layer (216, 316) and the second insulating layer (220, 320) to overlap the side surfaces and a bottom surface of the light-emitting element (100, 300) or to overlap the side surfaces of the light-emitting element (100, 300). [42] The method according to claim 40 or 41, wherein the light-emitting layer (100a, 300a) contains: a lower surface on which the first electrode (161) is arranged; an upper surface on which the second electrode (170) is arranged; and the side surfaces between the lower surface and the upper surface, wherein the lower surface and the upper surface of the light-emitting layer (100a, 300a) contain: a first flat projection on which the first electrode (161) is arranged, and a second flat projection on which the second electrode (170) is arranged; and stepped parts arranged at the edges of the first and second flat projections, the stepped parts have a lower height than each of the first and second flat projections, and the metal layers are arranged on at least a part of the side surfaces of the light-emitting element (100, 300) under the stepped parts. [43] The method according to any one of claims 40 to 42, wherein a lower surface of the light-emitting layer (100a, 300a) on which the first electrode (161) of the light-emitting element (100, 300) is disposed and the upper surface of the light-emitting layer (100a, 300a) on which the second electrode (170) is disposed have smaller widths than the side surfaces between the upper surface and the lower surface of the light-emitting layer (100a, 300a). [44] The method of any one of claims 40 to 43, wherein an area of the light-emitting element (100, 300) is less than or equal to an area of the bank structure (130). [45] The method according to any one of claims 40 to 44, further comprising: Forming a pad structure (230, 324) on a lower surface of the first electrode (161); and Forming an electrode line and a solder structure to which the light-emitting element (100, 300) is connected through the pad structure (230, 324) on the bench structure (130). [46] The method according to any one of claims 40 to 45, further comprising forming an insulating interlayer on the substrate (110, 210) containing the light-emitting element (100, 300). [47] The method according to claim 46, wherein the insulating interlayer has a stacked structure of any one or more of an organic insulating material and an inorganic insulating material containing an oxide film or a nitride film.

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