Light emitting device and display apparatus including the same

Abstract

Provided are a light emitting device and a display apparatus including the same, the light emitting device including a plurality of light emitting cells each configured to independently emit light, a common semiconductor layer provided on the plurality of light emitting cells, a first electrode provided on the common semiconductor layer, and a plurality of second electrodes provided on the plurality of light emitting cells, respectively, and spaced apart from the first electrode.

Description

TECHNICAL FIELD

[0001] Example embodiments of the present disclosure relate to a light emitting device, a display apparatus including the same, and a method of manufacturing the display apparatus. BACKGROUND

[0002] Light emitting devices (LEDs) are considered to be next-generation light sources having advantages of long lifespan, low power consumption, fast response speed, environmental friendliness, etc. compared to light sources according to the related art, and are used in various products such as lighting apparatuses, backlights of display apparatuses, etc. In particular, LEDs based on Group III nitride such as gallium nitride (GaN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium aluminum gallium nitride (InAlGaN), etc. are used as light emitting devices for light emission. SUMMARY

[0003] One or more example embodiments provide a light emitting device including a plurality of light emitting cells and a method of manufacturing the same.

[0004] One or more example embodiments also provide a display apparatus including a light emitting device including a plurality of light emitting cells and a method of manufacturing the same.

[0005] Additional aspects will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description, or can be learned by practice of example embodiments of the present disclosure.

[0006] According to an aspect of an example embodiment, there is provided a light emitting device including: a plurality of light emitting cells each configured to independently emit light; a common semiconductor layer provided on the plurality of light emitting cells; a first electrode provided on the common semiconductor layer; and a plurality of second electrodes provided on the plurality of light emitting cells, respectively, spaced apart from the first electrode.

[0007] The plurality of light emitting cells can be provided on a first surface of the common semiconductor layer, spaced apart from each other.

[0008] A width of each of the plurality of light emitting cells can be less than a width of the common semiconductor layer.

[0009] At least one of the plurality of light emitting cells can include a first semiconductor layer, an active layer, and a second semiconductor layer provided in sequence.

[0010] Each of the plurality of second electrodes can be provided on the second semiconductor layer.

[0011] A material of the first semiconductor layer can be the same as a material of the common semiconductor layer.

[0012] The first electrode can be provided on a first surface of the common semiconductor layer on which the plurality of light emitting cells are provided.

[0013] The first electrode can extend along a side surface of at least one of the plurality of light emitting cells toward an upper surface of the at least one of the plurality of light emitting cells.

[0014] The light emitting device can further include a first insulating layer provided between the first electrode and the plurality of light emitting cells.

[0015] The first insulating layer can be provided on each of the plurality of second electrodes.

[0016] The plurality of light emitting cells can be symmetrical about a central axis of the light emitting device.

[0017] The plurality of second electrodes can be symmetrical about a central axis of the light emitting device.

[0018] The first electrode can be symmetrical about a central axis of the light emitting device.

[0019] At least one of the first electrode and the plurality of second electrodes can be transparent.

[0020] At least a portion of a space between the plurality of light emitting cells can be filled with the first electrode.

[0021] The first electrode can be provided on a second surface of the common semiconductor layer, the second surface being different from a first surface of the common semiconductor layer on which the plurality of light emitting cells are provided.

[0022] The light emitting device can further include an insulating material filling at least a portion of a space between the plurality of light emitting cells.

[0023] An outer peripheral surface of the common semiconductor layer can have at least one of a circular shape, an elliptical shape, and a polygonal shape.

[0024] An outer peripheral surface of a combination of the plurality of light emitting cells can correspond to an outer peripheral surface of the common semiconductor layer.

[0025] According to an aspect of an example embodiment, there is provided a display device including a display layer including a plurality of light emitting devices, and a driving layer configured to drive the plurality of light emitting devices, the driving layer including a plurality of transistors electrically connected to the plurality of light emitting devices, respectively, wherein at least one of the plurality of light emitting devices includes a plurality of light emitting cells each configured to independently emit light, and a common semiconductor layer provided on the plurality of light emitting cells.

[0026] At least one of the plurality of light emitting devices can include a first electrode provided on the common semiconductor layer and electrically connected to the driving layer, and a plurality of second electrodes provided spaced apart from the first electrode and respectively provided on the plurality of light emitting cells.

[0027] The plurality of second electrodes can include a connection electrode electrically connected to the driving layer, and a non-connection electrode not electrically connected to the driving layer.

[0028] The light emitting cell provided on the non-connection electrode can not be configured to emit light.

[0029] The display layer can further include a planarization layer provided on the plurality of light emitting devices.

[0030] According to another aspect of an example embodiment, there is provided a light emitting device including a plurality of light emitting cells each configured to independently emit light, a common semiconductor layer provided on a first surface of each of the plurality of light emitting cells, a first electrode provided on the common semiconductor layer, an insulating layer provided between the first electrode and each of the plurality of light emitting cells, and a plurality of second electrodes provided spaced apart from the first electrode and respectively provided on a second surface opposite the first surface of each of the plurality of light emitting cells. BRIEF DESCRIPTION OF DRAWINGS

[0031] The above and / or other aspects, features and advantages of example embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, which illustrate by way of example example embodiments of the disclosure.

[0032] FIG. 1A is a cross-sectional view of a light emitting device according to an example embodiment;

[0033] FIG. 1B is a plan view of the light emitting device of FIG. 1A ;

[0034] FIG. 2A , FIG. 2B , FIG. 2C and FIG. 2D are reference views for describing a method of manufacturing a light emitting device according to an example embodiment;

[0035] FIG. 3 is a cross-sectional view of a light emitting device according to another example embodiment;

[0036] FIG. 4 is a cross-sectional view of a light emitting device filled with an insulating material according to an example embodiment;

[0037] FIG. 5 is a plan view of a light emitting device according to another example embodiment;

[0038] FIG. 6 is a plan view of a light emitting device including a plurality of sub-electrodes according to an example embodiment;

[0039] FIG. 7 is a plan view of a light emitting device in which a first electrode is disposed at an edge region according to an example embodiment;

[0040] FIG. 8 is a plan view of a light emitting device including three light emitting units according to an example embodiment;

[0041] FIG. 9 is a plan view of a light emitting device including four light emitting units according to an example embodiment;

[0042] FIG. 10 is a plan view of a light emitting device having different cross sections according to an example embodiment;

[0043] FIG. 11 is a plan view of an octagonal light emitting device according to another example embodiment;

[0044] FIG. 12A is a cross-sectional view of a light emitting device including a second insulating layer according to an example embodiment;

[0045] FIG. 12B is a cross-sectional view of a light emitting device including a second insulating layer according to another example embodiment;

[0046] FIG. 13 is a cross-sectional view of a light emitting device having a scattering pattern according to an example embodiment;

[0047] FIG. 14 is a cross-sectional view of a light emitting device including electrodes disposed on both surfaces thereof according to an example embodiment;

[0048] FIG. 15 is a reference view for describing a defect rate of a light emitting device according to an example embodiment;

[0049] FIG. 16A 、 FIG. 16B 、 FIG. 16C 、 FIG. 16D and FIG. 16E are reference views for describing a process of manufacturing a display device by using a light emitting device according to an example embodiment;

[0050] FIG. 17A 、 FIG. 17B 、 FIG. 17C 、 FIG. 17D and FIG. 17Eis a reference view for describing a process of manufacturing a display device by using a light emitting device according to another example embodiment; and

[0051] FIG. 18 is a view of a display device including a light emitting device according to another example embodiment. DETAILED DESCRIPTION

[0052] Reference will now be made in detail embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the example embodiments can have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the example embodiments are merely descriptive of aspects and are not intended to limit the aspects as described herein. Accordingly, the example embodiments are described with reference to the drawings only to explain aspects. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression "at least one of a, b, and c" should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0053] Hereinafter, example embodiments of the disclosure will be described in detail with reference to the accompanying drawings. Although example embodiments are described, these example embodiments are merely exemplary and those skilled in the art to which the disclosure pertains can make various modifications and changes from these descriptions. Throughout the drawings, like reference numerals refer to like elements. The sizes of components in the drawings can be exaggerated for ease of explanation.

[0054] When one constituent element is disposed "on" or "above" another constituent element, the constituent element can be directly on the other constituent element only or above the other constituent element in a non-contact manner.

[0055] Terms such as "first" and "second" are used herein only to describe various constituent elements, but the constituent elements are not limited by the terms. Such terms are merely for distinguishing one constituent element from another.

[0056] Expressions used in the specification in the singular form also include expressions in the plural form, unless the context clearly dictates otherwise. When one part "includes" a certain constituent element, unless otherwise specified, it can not be construed as excluding another constituent element but can be construed as further including another constituent element.

[0057] Further, terms such as "part", "unit", "module", and "block" stated in the specification can represent a unit processing at least one function or operation, and the unit can be embodied by hardware, software, or a combination of hardware and software.

[0058] The use of the terms "a" and "the" and similar referents in the context of describing the disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0059] Further, the steps of all methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The disclosure is not limited to the order of the steps described. Further, connecting lines or connectors shown in the various figures presented are intended to represent functional relationships and / or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections can be present in actual devices.

[0060] FIG. 1A is a cross-sectional view of the light emitting device 100 along line A-B of FIG. 1B . FIG. 1B is a plan view of the light emitting device 100 of FIG. 1A .

[0061] As shown in FIG. 1A , the light emitting device 100 can include an inorganic material-based light emitting diode, and the light emitting device 100 can emit light of a specific wavelength according to materials included in the light emitting device 100. The light emitting device 100 according to an example embodiment can have a micro size. For example, the width of the light emitting device 100 can be about 500 µm or less or about 100 µm or less.

[0062] The light emitting device 100 can include a plurality of light emitting cells 120 each configured to independently emit light, a common semiconductor layer 130 in contact with the light emitting cells 120, a first electrode 140 in contact with the common semiconductor layer 130, and a plurality of second electrodes 150 disposed to be spaced apart from the first electrode 140 and in contact with each of the light emitting cells 120.

[0063] The light emitting cells 120 can be arranged to be spaced apart from each other on a first surface of the common semiconductor layer 130. Although the drawing shows two light emitting cells 120, the embodiment is not limited thereto. The light emitting device 100 can include two or more light emitting cells 120. The light emitting cells 120 can be arranged one-dimensionally in one direction or two-dimensionally in two directions on the first surface of the common semiconductor layer 130.

[0064] The light emitting units 120 can each have the same shape. For example, a cross section of each light emitting unit 120 in a width direction, i.e., a lateral cross section, can be rectangular. A cross section of each light emitting unit 120 in a thickness direction, i.e., a side cross section, can be circular, elliptical, and / or polygonal. A width of each light emitting unit 120 can be smaller than a width of the common semiconductor layer 130. The above-described light emitting units 120 can be symmetrically arranged about a central axis X of the light emitting device 100.

[0065] Each light emitting unit 120 can include a first semiconductor layer 121, an active layer 122, and a second semiconductor layer 123 arranged in the order on the common semiconductor layer 130.

[0066] The first semiconductor layer 121 can include, for example, an n-type semiconductor. However, the embodiments are not necessarily limited thereto, and in some cases, the first semiconductor layer 121 can include a p-type semiconductor. The first semiconductor layer 121 can include an n-type semiconductor based on Group III-V, such as n-GaN. The first semiconductor layer 121 can have a single layer or a multi-layer structure. For example, the first semiconductor layer 121 can include any one of InAlGaN, GaN, AlGaN, InGaN, aluminum nitride (AlN), indium nitride (InN), and a semiconductor layer doped with a conductive dopant such as silicon (Si), germanium (Ge), tin (Sn), or the like.

[0067] The active layer 122 can be arranged on an upper surface of the first semiconductor layer 121. The active layer 122 can generate light when an electron and a hole combine with each other, and have a multi-quantum well (MQW) structure or a single-quantum well (SQW) structure. The active layer 122 can include a semiconductor based on Group III-V, such as InGaN, GaN, AlGaN, aluminum indium gallium nitride (AlInGaN), or the like. A cladding layer doped with a conductive dopant can be formed above and below the active layer 122. In an example, the cladding layer can include an AlGaN layer or an InAlGaN layer.

[0068] The second semiconductor layer 123 can be provided on an upper surface of the active layer 122 opposite the first semiconductor layer 121, and can include a semiconductor layer of a different type from the first semiconductor layer 121. For example, the second semiconductor layer 123 can include a p-type semiconductor layer. The second semiconductor layer 123 can include, for example, InAlGaN, GaN, AlGaN, and / or InGaN, and can be a semiconductor layer doped with a conductive dopant such as magnesium (Mg) or the like.

[0069] The common semiconductor layer 130 can be in contact with the light emitting cells 120. The material of the common semiconductor layer 130 can be the same as that of the first semiconductor layer 121. For example, the common semiconductor layer 130 can include an n-type semiconductor. For example, the common semiconductor layer 130 can include an n-type semiconductor based on group III-V, such as n-GaN. The common semiconductor layer 130 can have a single layer or a multi-layer structure. For example, the common semiconductor layer 130 can include any one of semiconductor materials of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and include a semiconductor layer doped with a conductive dopant such as Si, Ge, Sn, or the like.

[0070] A cross section of the common semiconductor layer 130 in a width direction, i.e., a lateral cross section, can be rectangular. A cross section of the common semiconductor layer 130 in a thickness direction can have a circular shape, an elliptical shape, and / or a polygonal shape, etc. For example, a side cross section of the common semiconductor layer 130 can be rectangular.

[0071] The first electrode 140 can be in contact with the common semiconductor layer 130. The first electrode 140 can be in contact with the common semiconductor layer 130 on a first surface of the common semiconductor layer 130 on which the light emitting cells 120 are disposed. The first electrode 140 can extend along the side surfaces of the light emitting cells 120 toward the upper surfaces of the light emitting cells 120. For example, the first electrode 140 can be in contact with the common semiconductor layer 130 in an intermediate region of the common semiconductor layer 130 between adjacent light emitting cells 120, and can be disposed to extend along the side surfaces of the light emitting cells 120 adjacent to each other toward the upper surfaces of the light emitting cells 120.

[0072] The first electrode 140 can be symmetrically disposed with respect to a central axis X of the light emitting device 100. In FIG. 1A In particular, the first electrode 140 can be linearly symmetrically disposed with respect to the central axis X of the light emitting device 100.

[0073] The first electrode 140 can include a conductive material. For example, the first electrode 140 can include a transparent conductive material and can be a transparent electrode. The first electrode 140 can include a metal such as silver (Ag), Mg, aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), and an alloy thereof; a conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO); a conductive polymer such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT), etc.

[0074] The light emitting device 100 can include second electrodes 150 in contact with the light emitting cells 120, respectively. The second electrodes 150 can be in contact with the second semiconductor layers 123 of the light emitting cells 120, respectively. The second electrodes 150 can be symmetrically arranged with respect to the central axis X of the light emitting device 100. In the drawings, the second electrodes 150 are arranged linearly symmetrically with respect to the central axis X of the light emitting device 100. Like the first electrodes 140, the second electrodes 150 can include a transparent conductive material.

[0075] The light emitting device 100 can further include a first insulating layer 160 provided around the side surfaces of the light emitting cells 120 and adjacent to the side surfaces of the light emitting cells 120. A partial area of the first insulating layer 160 can extend toward the upper surfaces of the light emitting cells 120. Accordingly, the first insulating layer 160 can prevent the first electrodes 140 from contacting the active layers 122 and the second semiconductor layers 123 of each of the light emitting cells 120. In the drawings, the first insulating layer 160 is shown as being arranged to be spaced apart from the second electrodes 150. However, embodiments are not limited thereto. The first insulating layer 160 in contact with the second electrodes 150 can prevent the second semiconductor layers 123 from being exposed to the outside.

[0076] Each of the light emitting cells 120 can independently emit light in response to an electrical signal applied to the first electrodes 140 and the second electrodes 150 corresponding to the light emitting cells 120, respectively. Accordingly, even when any one of the light emitting cells 120 is defective, the light emitting cells 120 can normally emit light, and thus, the light emitting device 100 as a whole can normally operate. Accordingly, the defect rate of the light emitting device 100 can be reduced in proportion to the number of the light emitting cells 120.

[0077] FIG. 2A to FIG. 2D is a reference view for describing a method of manufacturing a light emitting device 100 according to an example embodiment.

[0078] As FIG. 2A indicated, a first semiconductor material layer 121a, an active material layer 122a, and a second semiconductor material layer 123a can be sequentially formed on a first substrate 210. The first substrate 210 can be a substrate for growing a semiconductor material. The first substrate 210 can include various materials for general semiconductor processes. For example, a silicon substrate, a sapphire substrate, or the like can be used as the first substrate 210.

[0079] The first semiconductor material layer 121a, the active material layer 122a, and the second semiconductor material layer 123a can be formed by a method such as metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), plasma-enhanced CVD (PECVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), or the like.

[0080] As FIG. 2BAs illustrated, the common semiconductor layer 130 and the light emitting unit 120 can be formed by patterning the first semiconductor material layer 121a, the active material layer 122a, and the second semiconductor material layer 123a. The common semiconductor layer 130 and the light emitting unit 120 can be referred to as a main body. A trench T can be formed in the first semiconductor material layer 121a, the active material layer 122a, and the second semiconductor material layer 123a to expose the first semiconductor material layer 121a by penetrating the second semiconductor material layer 123a and the active material layer 122a. A partial region of the first semiconductor material layer 121a can become the common semiconductor layer 130, and other regions of the first semiconductor material layer 121a can become the first semiconductor layer 121 of the light emitting unit 120. However, embodiments are not limited thereto. The first semiconductor material layer 121a can entirely become the common semiconductor layer 130, and the light emitting unit 120 can not include the first semiconductor layer 121. For example, the light emitting unit 120 can include only the active layer 122 and the second semiconductor layer 123.

[0081] As illustrated, FIG. 2C A first insulating layer 160 can be formed in the trench T between the light emitting units 120. The first insulating layer 160 can extend toward the upper surface of the light emitting unit 120 by being provided around and adjacent to the side surface of the light emitting unit 120. In addition, the first insulating layer 160 can extend toward the common semiconductor layer 130 while exposing a partial region of the common semiconductor layer 130.

[0082] As illustrated, FIG. 2D A first electrode 140 in contact with the common semiconductor layer 130 and a second electrode 150 in contact with the second semiconductor layer 123 can be formed. The first electrode 140 can be in contact with the common semiconductor layer 130 at the bottom surface of the trench T and extend toward the first insulating layer 160 on the upper surface of the light emitting unit 120 by passing through the side surface of the light emitting unit 120. By the first insulating layer 160, the first electrode 140 can be prevented from contacting the active layer 122 and the second semiconductor layer 123 of each light emitting unit 120. The second electrode 150 can be disposed on the upper surface of the second semiconductor layer 123 of the light emitting unit 120 separately from the first electrode 140.

[0083] FIG. 3 is a cross-sectional view of a light emitting device 100a according to another example embodiment. When compared with FIG. 1A to FIG. 3 FIG. 3 ​The first electrode 140 of the light emitting device 100a according to an example embodiment can fill at least a portion of a space between adjacent light emitting cells 120. When the space between the light emitting cells 120 of the light emitting device 100 is empty, the mechanical strength of the light emitting device 100 can decrease. Since at least a portion of the space between the light emitting cells 120 is filled with the first electrode 140, the mechanical strength of the light emitting device 100 can be prevented from decreasing.

[0084] FIG. 4 is a cross-sectional view of a light emitting device 100b filled with an insulating material according to an example embodiment. FIG. 4 The light emitting device 100b according to an example embodiment can further include an insulating material 170 filling at least a portion of a space between adjacent light emitting cells 120. When the space between the light emitting cells 120 is filled with the same material as the first electrode 140, the thickness of the first electrode 140 increases, and thus the transparency of the first electrode 140 disposed in the space between the light emitting cells 120 can decrease. Then, since light generated by the active layer 122 is reflected by the first electrode 140, the light emitting efficiency can decrease. Thus, since at least a portion of the space between the light emitting cells 120 is filled with the transparent insulating material 170, the light emitting efficiency can be prevented from decreasing.

[0085] FIG. 5 is a plan view of a light emitting device 100c according to another example embodiment. As FIG. 5 indicated, the first electrode 140 can be disposed in a middle region of the light emitting device 100c, and the second electrode 150 can be disposed in an edge region of the light emitting device 100c. The first electrode 140 can be disposed in contact with the common semiconductor layer 130 between the light emitting cells 120 and extend along a side surface of the light emitting cell 120 toward an upper surface of the light emitting cell 120. The second electrode 150 can be disposed on the upper surface of each of the light emitting cells 120. The first electrode 140 and the second electrode 150 can be symmetrically disposed about a central axis of the light emitting device 100.

[0086] FIG. 6 is a plan view of a light emitting device 100d including a plurality of sub-electrodes according to an example embodiment. When compared with FIG. 5 , FIG. 6 , FIG. 6 The second electrode 150 included in the light emitting device 100d according to an example embodiment can include a plurality of sub-electrodes 151. For example, each of the second electrodes 150 can include a plurality of sub-electrodes 151. Since the second electrode 150 is implemented as a plurality of sub-electrodes 151, the distance between the first electrode 140 and the second electrode 150 can be maintained at a certain distance or more. The sub-electrodes 151 can also be linearly symmetric or rotationally symmetric about a central axis of the light emitting device 100d.

[0087] FIG. 7is a plan view of a light emitting device 100e according to an example embodiment in which a first electrode is disposed in an edge region. As FIG. 7 indicated, a first electrode 140 can be disposed in an edge region of the light emitting device 100e, and a second electrode 150 can be disposed in a middle region of the light emitting device 100e. The first electrode 140 can be disposed in contact with the common semiconductor layer 130 at edges of the light emitting units 120 and extend along side surfaces of the light emitting units 120 toward upper surfaces of the light emitting units 120. The second electrode 150 can be disposed in the middle region of the light emitting device 100e on the upper surfaces of the light emitting units 120. The first electrode 140 and the second electrode 150 can be disposed rotationally symmetrically or linearly symmetrically about a central axis of the light emitting device 100e.

[0088] FIG. 8 is a plan view of a light emitting device 100f including three light emitting units according to an example embodiment. When compared with FIG. 1B and FIG. 8 FIG. 8 The light emitting device 100f can include three light emitting units 120. The first electrode 140 can be in contact with the common semiconductor layer 130 and extend along three side surfaces of the light emitting units 120 toward upper surfaces of the three light emitting units 120. The three second electrodes 150 can be disposed on the upper surfaces of the light emitting units 120, respectively.

[0089] FIG. 9 is a plan view of a light emitting device 100g including four light emitting units 120 according to an example embodiment. FIG. 9 The light emitting device 100g can include four light emitting units 120. The first electrode 140 can be disposed in a central region of the light emitting device 100g, and the four second electrodes 150 can be disposed in edge regions of the light emitting device 100g. The first electrode 140 and the second electrodes 150 can be disposed rotationally symmetrically or linearly symmetrically about a central axis of the light emitting device 100g.

[0090] As the number of light emitting units increases, the defect rate of the light emitting device can decrease. The cross-sections of the light emitting device and the light emitting units described above correspond to each other. For example, when the cross-section of the light emitting device is polygonal, the cross-section of the light emitting unit is also polygonal. However, embodiments are not limited thereto. The cross-section of the light emitting device can be different from the cross-section of the light emitting unit.

[0091] FIG. 10 is a plan view of a light emitting device 100h having different cross-sections according to an example embodiment. As FIG. 10 ​As shown, the cross section of the light emitting device 100h can be circular. For example, the cross section of the outer peripheral surface of the common semiconductor layer 130 can be circular, and the cross section of the outer peripheral surface of the combination of the light emitting cells 120 can be circular. However, the cross section of the outer peripheral surface of each of the light emitting cells 120 can be sector-shaped. The first electrode 140 can be disposed at a central region of the light emitting device 100h, and the second electrode 150 can be disposed at an edge region of the light emitting device 100h, but embodiments are not limited thereto. For example, the first electrode 140 and the second electrode 150 can be disposed in reverse. The first electrode 140 and the second electrode 150 can be symmetrical about a central axis of the light emitting device 100h. For example, the first electrode 140 and the second electrode 150 can be rotationally symmetrical or line symmetrical about the central axis of the light emitting device 100h.

[0092] FIG. 11 is a plan view of a light emitting device 100i having an octagonal cross section according to another example embodiment. As shown, FIG. 11 the cross section of the light emitting device 100i can be octagonal. For example, the cross section of the outer peripheral surface of the common semiconductor layer 130 can be octagonal, and the cross section of the outer peripheral surface of the combination of the light emitting cells 120 can be octagonal. However, embodiments are not limited thereto. For example, the cross section of the outer peripheral surface of each of the light emitting cells 120 can be triangular. The first electrode 140 can be disposed at a central region of the light emitting device 100i, and the second electrode 150 can be disposed at an edge region of the light emitting device 100i, but embodiments are not limited thereto, and the first electrode 140 and the second electrode 150 can be disposed in reverse.

[0093] FIG. 12A is a cross-sectional view of a light emitting device 100j including a second insulating layer 165 according to an example embodiment. As shown, FIG. 12A The second insulating layer 165 can be disposed at a side surface of the light emitting device 100j. The second insulating layer 165 can be in contact with the second electrode 150 on the upper surfaces of the light emitting cells 120, respectively. The second insulating layer 165 along the side surfaces of the light emitting cells 120 and the common semiconductor layer 130 can surround the lower surface of the common semiconductor layer 130 and be provided on the lower surface of the common semiconductor layer 130. The first insulating layer 160 can be in contact with the second electrode 150 by extending toward the upper surfaces of the light emitting cells 120 while being provided surrounding the side surfaces of the light emitting cells 120 and adjacent to the side surfaces of the light emitting cells 120. In addition to functioning as a film that performs an electrical insulation function between the light emitting cells 120 and the first and second electrodes 140 and 150, the first insulating layer 160 and the second insulating layer 165 can also function as a protective film for protecting the light emitting device 100j from external influences.

[0094] FIG. 12Bis a cross-sectional view of a light emitting device 100k including a second insulating layer 165a according to another exemplary embodiment. As shown, FIG. 12B The second insulating layer 165a can be disposed at a side surface of the light emitting device 100k. The second insulating layer 165a can be in contact with the second electrode 150 on an upper surface of the light emitting cell 120, respectively. The second insulating layer 165a can surround a side surface of the light emitting cell 120, and can expose at least a partial region of the common semiconductor layer 130.

[0095] FIG. 13 is a cross-sectional view of a light emitting device 100l having a scattering pattern according to an exemplary embodiment. As shown, FIG. 13 The scattering pattern 180 can be further disposed on the common semiconductor layer 130 of the light emitting device 100l. The scattering pattern 180 can be disposed on a lower surface of the common semiconductor layer 130 to protrude outward. However, embodiments are not limited thereto. The scattering pattern 180 can be disposed to be embedded in the common semiconductor layer 130. The scattering pattern 180 can include a low dielectric constant material, for example, a material having a dielectric constant of 4 or less.

[0096] The electrodes of the light emitting device are described above to be disposed to face one direction. Since the electrodes are disposed to face one direction, the light emitting device 100 can be more easily transferred to another substrate. However, embodiments are not limited thereto. The first electrode 140 and the second electrode 150 can be disposed on different surfaces of the light emitting device, and the formation times of the first electrode 140 and the second electrode 150 can be different from each other. For example, after the second electrode 150 is formed on a body constituted of the common semiconductor layer 130 and the light emitting cell 120, the body where the second electrode 150 is formed thereon can be transferred to another substrate. Then, the first electrode 140 can be formed on the body.

[0097] FIG. 14 is a view of a light emitting device 100m including electrodes disposed on both surfaces thereof according to an exemplary embodiment. As shown, FIG. 14 The first electrode 140 can be disposed on a lower surface of the common semiconductor layer 130, i.e., a lower surface of the light emitting device 100m, and the second electrode 150 can be disposed on an upper surface of the light emitting cell 120, i.e., an upper surface of the light emitting device 100m opposite to the first electrode 140. Since the first electrode 140 and the second electrode 150 are disposed on different surfaces of the light emitting device 100m, electrodes of a large size can be secured.

[0098] When a light emitting device is manufactured in a micro size, defects are often generated in the growth of a semiconductor material. A defective light emitting device which does not emit light due to the defects or the like can be manufactured. Repairing the defective light emitting device 100 can cause processing difficulty or reduce a processing yield.

[0099] Since each light emitting cell of the light emitting device according to an example embodiment independently receives an electrical signal through a corresponding second electrode, each light emitting cell can independently emit light. Thus, even when one light emitting cell cannot emit light due to a defect or the like, other light emitting cells can emit light, and thus the defect rate of the light emitting device can be reduced. For example, the defect rate of a light emitting device having two light emitting cells can be reduced to 1 / 2 of the defect rate of a light emitting device having one light emitting cell, and the defect rate of a light emitting device having four light emitting cells can be reduced to 1 / 4 of the defect rate of a light emitting device including one light emitting cell.

[0100] FIG. 15 is a reference view for describing the defect rate of the light emitting device 100 according to an example embodiment. As shown in FIG. 15 the electrode pattern 190 for electrically connecting the driving layer can be formed on the light emitting device 100. The electrode pattern 190 can include a first wiring 191 connected to the first electrode 140 and a plurality of second wirings 192 and 193 connected to the second electrode 150. An electrical signal can be applied to the light emitting device 100 through the first and second wirings 191, 192, and 193, and among the light emitting cells 120, the first light emitting cell 120a can not emit light. However, since the second light emitting cell 120b emits light, the light emitting device 100 can still emit light. By cutting off the third wiring 193 connected to the first light emitting cell 120a, the current can be concentrated on the second light emitting cell 120b, and thus the reduction in brightness of the light emitting device 100 due to the defective first light emitting cell 120a can be reduced. The second electrode of the first light emitting cell 120a connected to the cut-off third wiring 193 can be referred to as a non-connected electrode, and the second electrode of the second light emitting cell 120b connected to the non-cut-off second wiring 192 can be referred to as a connected electrode.

[0101] The light emitting devices 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100l, and 100m described above can be used as a light emitting source of various devices. In an example, the light emitting devices 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100l, and 100m can be applied to a lighting device or a self-light emitting display device. For example, the light emitting devices 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100l, and 100m can become one constituent element of a display device by being transferred through a fluid self-assembly method, a pick-and-place method, or the like.

[0102] FIG. 16A to FIG. 16E is a reference view for describing a process of manufacturing a display apparatus by using the light emitting device 100 according to an example embodiment.

[0103] Referring to FIG. 16A The target substrate 410 can be aligned on the transfer substrate 300 to which the light emitting device 100 is transferred. The light emitting device 100 can be transferred to the transfer substrate 300 by a fluid self-assembly method, a pick-and-place method, or the like. The target substrate 410 can include a substrate 412 and a driving layer 414. The substrate 412 can include an insulating material such as glass, an organic polymer, a crystal, or the like. In addition, the substrate 412 can include a flexible material that is bendable or foldable, and can have a single-layer structure or a multi-layer structure. The driving layer 414 can include a transistor, an electrode pattern, or the like for driving the light emitting device 100. The electrode of the light emitting device 100 can be arranged to face the electrode pattern formed on the target substrate 410.

[0104] As FIG. 16B indicated, the light emitting device 100 can be transferred to the target substrate 410. For example, the light emitting device 100 can be transferred to the target substrate 410 by a bonding method. After the transfer substrate 300 and the target substrate 410 are aligned with each other, the light emitting device 100 can be bonded to the target substrate 410 by using thermal compression, ultrasound, light (laser or UV), or the like. For example, when thermal compression is applied between the electrode of the light emitting device 100 and the electrode pattern of the target substrate 410, the electrode of the light emitting device 100 can be compressed in proportion to the pressure and temperature to be bonded to the electrode pattern of the target substrate 410.

[0105] After the light emitting device 100 is transferred to the target substrate 410, the transfer substrate 300 is removed. As FIG. 16C indicated, the target substrate 410 can be flipped over with the light emitting device 100 facing upward.

[0106] When the transfer substrate 300 is a target substrate including a driving layer, the light emitting device 100 can be bonded to the transfer substrate 300 without additional transfer.

[0107] As FIG. 16DAs shown, a planarization layer 420 can be formed on the light-emitting device 100. The planarization layer 420 can cover the light-emitting device 100 while having a planarized upper surface. The planarization layer 420 can mitigate the steps created by the constituent elements arranged below the planarization layer 420 and prevent oxygen, moisture, etc., from penetrating into the light-emitting device 100. The planarization layer 420 may include an insulating material. The planarization layer 420 may include an organic insulating film (propylene or silicon-based polymer) or an inorganic insulating film (silicon oxide (SiO2), silicon nitride (SiN), aluminum oxide (Al2O3), or titanium oxide (TiO2)), etc., but the embodiments are not limited to these. The planarization layer 420 may have a multilayer structure including various insulating materials with different dielectric constants.

[0108] like FIG. 16E As shown, a color conversion layer 430 can be formed on the planarization layer 420. When the light-emitting device 100 emits light of the same wavelength, the color conversion layer 430 can include first to third color conversion patterns 431, 433, and 435 for converting the light generated by the light-emitting device 100 into light of a certain wavelength. Each of the first to third color conversion patterns 431, 433, and 435 can correspond to each sub-pixel. For example, the first color conversion pattern 431 can correspond to the first sub-pixel SP1, the second color conversion pattern 433 can correspond to the second sub-pixel SP2, and the third color conversion pattern 435 can correspond to the third sub-pixel SP3. The color conversion layer 430 can be formed by photolithography.

[0109] In the accompanying drawings, a light-emitting device 100 is shown arranged in a sub-pixel. However, the implementation is not limited to this. A sub-pixel may include two or more light-emitting devices 100. Since each light-emitting device 100 includes a light-emitting unit 120, even when one or more of the light-emitting units 120 are not emitting light, another of the light-emitting units 120 can still emit light. Therefore, the defect rate of the sub-pixel can be reduced, and sub-pixel repair is unnecessary.

[0110] although FIG. 16E The illustration shows light-emitting devices 100 emitting light of the same wavelength, but the implementation is not limited to this. When each light-emitting device 100 performs a sub-pixel function by emitting different light (e.g., red, blue, and green light), the display device may not need to include a color conversion layer. Although the method of manufacturing the display device uses... FIG. 1A The light-emitting device 100 is used, but the implementation is not limited to this. It can be achieved by using... FIG. 3 to FIG. 14 Display devices are manufactured using light-emitting devices 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100l, and 100m.

[0111] In the display device 400 manufactured by FIG. 16A to FIG. 16E In the display device 400 manufactured by

[0112] FIG. 17A to FIG. 17E is a reference view for describing a process of manufacturing a display device 500 by using the light emitting device 100 according to another example embodiment.

[0113] As FIG. 17A indicated, a driving layer 514 can be formed on a substrate 512. The driving layer 514 can include a TFT, a first electrode pattern EL1, a capacitor, etc.

[0114] As FIG. 17B indicated, a flexible partition wall 520 having a hole H can be formed on the driving layer 514. The flexible partition wall 520 can include a polymer layer 522 and a metal layer 524. The metal layer 524 can be electrically connected to the first electrode pattern EL1 of the driving layer 514 via a hole h formed in the polymer layer 522. The substrate 512, the driving layer 514, and the flexible partition wall 520 can form a transfer substrate.

[0115] As FIG. 17C indicated, the light emitting device 100 can be transferred to the transfer substrate in the hole H. The light emitting device 100 is the same as FIG. 1A indicated, but the embodiment is not limited thereto. The light emitting device 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, and 100l of FIG. 3 to FIG. 14 can be transferred to the transfer substrate. The light emitting device 100 can be transferred by a fluid self-assembly method or a pick-and-place method.

[0116] As FIG. 17D indicated, an insulating layer 530 for covering at least a portion of the flexible partition wall 520 and the light emitting device 100 can be formed, and a second electrode pattern EL2 for electrically connecting an upper electrode of the light emitting device 100 with the driving layer 514 can be formed. The second electrode pattern EL2 can be electrically connected to the first electrode pattern EL1 of the driving layer 514 through the metal layer 524 of the flexible partition wall 520. The insulating layer 530 can prevent oxygen, moisture, etc. from penetrating into the light emitting device 100.

[0117] As FIG. 17E indicated, a planarization layer 540 can be formed on the insulating layer 530 and the second electrode pattern EL2. Then, a color conversion layer can be further formed.

[0118] FIG. 18 is a view of a display apparatus 600 including the light emitting device 100 according to another example embodiment. FIG. 18 The display apparatus 600 of FIG. 1 can include a third electrode pattern EL3 disposed under the light emitting device 100 and a fourth electrode pattern EL4 disposed over the light emitting device 100. The third electrode pattern EL3 can be electrically connected to any one of the first electrode 140 and the second electrode 150 of the light emitting device 100, and the fourth electrode pattern EL4 can be electrically connected to the other of the first electrode 140 and the second electrode 150 of the light emitting device 100. Even when the second electrode pattern EL4 is electrically connected to the second electrode 150 of the light emitting device 100, a defective cell of the light emitting cell 120 of the light emitting device 100 can not be electrically connected to the fourth electrode pattern EL4. For example, the second electrode of the defective cell can be electrically disconnected from the second electrode pattern EL4 in a manufacturing process of the display apparatus.

[0119] The display apparatuses including the above-described light emitting devices 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100l, and 100m can be used for various electronic apparatuses. For example, the display apparatuses can be applied to a television (TV), a notebook computer, a mobile phone, a smart phone, a smart pad (PD), a portable media player (PMP), a personal digital assistant (PDA), a navigation, various wearable devices such as a smart watch or a head-mounted display, etc.

[0120] It is to be understood that the example embodiments described herein are to be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example embodiment should typically be considered as being applicable to other similar features or aspects in other example embodiments.

[0121] While example embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details can be made therein without departing from the spirit and scope as defined by the following claims and the equivalents thereof.

[0122] This application is based on provisional U.S. Patent Application No. 63 / 145,166 filed in the U.S. Patent and Trademark Office on February 3, 2021, and Korean Patent Application No. 10-2021-0057479 filed in the Korean Intellectual Property Office on May 3, 2021, and claims priority to both of these applications, the disclosures of which are incorporated by reference herein in their entireties.

Claims

1. A display device comprising: a display layer including a plurality of light emitting devices; and a driving layer configured to drive the plurality of light emitting devices, the driving layer including a plurality of transistors electrically connected to the plurality of light emitting devices, respectively, wherein at least one of the plurality of light emitting devices includes: a plurality of light emitting cells each configured to independently emit light; a common semiconductor layer provided under the plurality of light emitting cells; a first electrode provided on the common semiconductor layer; and a plurality of second electrodes provided spaced apart from the first electrode and on the plurality of light emitting cells, respectively, an electrode pattern electrically connecting the driving layer to the plurality of light emitting devices, the electrode pattern including a first wiring connected to the first electrode and a plurality of second wirings connected to the plurality of second electrodes, respectively, wherein, when the plurality of light emitting cells include a first light emitting cell that does not emit light and a second light emitting cell that emits light, a current is concentrated on the second light emitting cell due to the second wiring connected to the first light emitting cell being cut off. 2.The display device of claim 1, wherein the plurality of light emitting cells are provided spaced apart from each other on a first surface of the common semiconductor layer. 3.The display device of claim 1, wherein a width of each of the plurality of light emitting cells is less than a width of the common semiconductor layer. 4.The display device of claim 1, wherein at least one of the plurality of light emitting cells includes a first semiconductor layer, an active layer, and a second semiconductor layer provided in this order. 5.The display device of claim 4, wherein each of the plurality of second electrodes is provided on the second semiconductor layer. 6.The display device of claim 4, wherein a material of the first semiconductor layer is the same as a material of the common semiconductor layer. 7.The display device of claim 1, wherein the first electrode is provided on a first surface of the common semiconductor layer on which the plurality of light emitting cells are provided. 8.The display device of claim 1, wherein the first electrode extends along a side surface of at least one of the plurality of light emitting cells toward an upper surface of the at least one of the plurality of light emitting cells. 9.The display device of claim 1, further comprising: a first insulating layer provided between the first electrode and the plurality of light emitting cells. 10.The display device of claim 9, wherein the first insulating layer contacts each of the plurality of second electrodes. 11.The display device of claim 1, wherein the plurality of light emitting cells are symmetrical about a central axis of the light emitting device. 12.The display device of claim 1, wherein the plurality of second electrodes are symmetrical about a central axis of the light emitting device. 13.The display device of claim 1, wherein the first electrode is symmetrical about a central axis of the light emitting device. 14.The display device of claim 1, wherein at least one of the plurality of second electrodes and the first electrode is transparent. ​ 15. The display device according to claim 1, wherein at least part of spaces between the plurality of light emitting cells is filled with the first electrode.

16. The display device according to claim 1, wherein the first electrode is provided on a second surface of the common semiconductor layer, the second surface being different from a first surface of the common semiconductor layer on which the plurality of light emitting cells are provided.

17. The display device according to claim 1, further comprising: an insulating material filling at least part of spaces between the plurality of light emitting cells.

18. The display device according to claim 1, wherein an outer peripheral surface of the common semiconductor layer has at least one of a circular shape, an elliptical shape, and a polygonal shape.

19. The display device according to claim 18, wherein an outer peripheral surface of a combination of the plurality of light emitting cells corresponds to the outer peripheral surface of the common semiconductor layer.

20. The display device according to claim 1, wherein the display layer further comprises a planarization layer provided on the plurality of light emitting devices.

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