Light-emitting device and light-emitting module comprising same

Abstract

Disclosed is a light-emitting device comprising a semiconductor layer, a support layer supporting the semiconductor layer, a first electrode disposed between the support layer and the semiconductor layer, and a second electrode disposed on the semiconductor layer. The semiconductor layer includes a first conductivity type semiconductor layer disposed on the first electrode and electrically connected to the first electrode, an active layer covering the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer covering the active layer and electrically connected to the second electrode, and a cross-sectional length of a first surface of the first conductivity type semiconductor layer, which faces the first electrode, is shorter than a cross-sectional length of a second surface thereof facing the active layer.

Description

Light-emitting device and light-emitting module including the same

[0001] The present invention relates to a light-emitting device and a light-emitting module including the same.

[0002] A light-emitting diode (LED) is a light-emitting device that emits light when current is applied. Recently, light-emitting diodes are being used in various fields such as display devices, automotive lamps, and general lighting. Furthermore, light-emitting diodes have the advantages of a long lifespan, low power consumption, and fast response speed. By fully utilizing these advantages, they are rapidly replacing existing light sources. For example, a display device using light-emitting diodes can be obtained by forming structures of red (Red, R), green (Green, G), and blue (Blue, B) light-emitting diodes (LEDs) that are individually grown on a final substrate.

[0003] Specifically, the light-emitting diode is formed by growing epitaxial layers on a substrate and includes an N-type semiconductor layer, a P-type semiconductor layer, and an active layer interposed between them. An N-electrode pad is formed on the N-type semiconductor layer and a P-electrode pad is formed on the P-type semiconductor layer, so that the light-emitting diode is electrically connected to an external power source through the electrode pads and driven. At this time, current can flow from the P-electrode pad through the semiconductor layers to the N-electrode pad, and light generated through the recombination of electrons and holes in the active layer can be emitted.

[0004] The present invention aims to provide a light-emitting device and a light-emitting module including the same, which can suppress local heat generation and improve light-emitting efficiency by optimizing the thickness and cross-sectional shape of the first conductivity semiconductor layer, the active layer, and the second conductivity semiconductor layer of the light-emitting element to improve the current flow and diffusion path.

[0005] The present invention aims to provide a light-emitting device and a light-emitting module including the same, which can induce a more uniform distribution of current throughout the active layer, stabilize the flow of current, and improve luminous efficiency and reliability by designing the cross-sectional length of the first surface facing the first electrode of the first conductive semiconductor layer to be shorter than the cross-sectional length of the second surface facing the active layer.

[0006] The present invention aims to provide a light-emitting device and a light-emitting module including the same, which can prevent the problem of current concentration in a specific region and improve current spreading by forming the thickness of the central and outer parts of a first conductive semiconductor layer differently.

[0007] The present invention aims to provide a light-emitting device and a light-emitting module including the same, which can expand the distribution of emission wavelengths and improve color uniformity by forming a difference in thickness between the central and outer parts and a difference in indium (In) composition within the active layer.

[0008] The present invention aims to provide a light-emitting device and a light-emitting module including the same, which can expand the current diffusion path and increase luminous efficiency by extending the cross-sectional length of the surface of a second conductivity type semiconductor layer.

[0009] The present invention aims to provide a light-emitting device and a light-emitting module including the same, which can induce uniform injection of current and realize stable light-emitting characteristics across the entire light-emitting region by designing the width of an opening formed in an insulating layer above a second conductivity-type semiconductor layer to be smaller than the cross-sectional length of a first conductivity-type semiconductor layer.

[0010] The present invention aims to provide a light-emitting device and a light-emitting module including the same, which can improve light emission characteristics, light output, and light emission uniformity by precisely controlling resistance distribution and current flow through designing a first conductive semiconductor layer in various cross-sectional shapes such as arcuate or trapezoidal.

[0011] A light-emitting device according to one embodiment of the present invention may include a semiconductor layer, a support layer supporting the semiconductor layer, a first electrode disposed between the support layer and the semiconductor layer, and a second electrode disposed on the semiconductor layer.

[0012] In one embodiment, the semiconductor layer may include a first conductivity type semiconductor layer disposed on the first electrode and electrically connected to the first electrode, an active layer covering the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer covering the active layer and electrically connected to the second electrode.

[0013] In one embodiment, the cross-sectional length of the first surface facing the first electrode among the first conductive semiconductor layers may be shorter than the cross-sectional length of the second surface facing the active layer.

[0014] In one embodiment, the light-emitting device may further include a second insulating layer that covers the second conductive semiconductor layer and has an opening for connecting the second conductive semiconductor layer and the second electrode.

[0015] In one embodiment, the width of the opening in cross-section may be smaller than the cross-sectional length of the first surface.

[0016] In one embodiment, the light-emitting device may further include a first insulating layer disposed on the support layer and surrounding the first conductive semiconductor layer.

[0017] In one embodiment, the thickness of the first conductive semiconductor layer at the center of the cross-section may be different from the thickness of the first conductive semiconductor layer at the outer edge.

[0018] In one embodiment, the thickness of the first conductive semiconductor layer may be maximum at the center.

[0019] In one embodiment, the first conductive semiconductor layer may have an arc-shaped cross-sectional shape.

[0020] In one embodiment, the angle formed by two line segments connecting the vertex of the first conductive semiconductor layer and the lower edges of the first conductive semiconductor layer on each side in cross-section may be an obtuse angle.

[0021] In one embodiment, the vertical length of the first conductive semiconductor layer at the bottom center of the cross-section may be shorter than the length from the bottom center to the bottom edge.

[0022] In one embodiment, the length of the surface of the second conductive semiconductor layer on the cross-section may be longer than the length of the second surface.

[0023] In one embodiment, the thickness of the second conductive semiconductor layer at the center of the cross-section may be different from the thickness of the second conductive semiconductor layer at the outer edge.

[0024] In one embodiment, the thickness of the active layer at the center of the cross-section may be different from the thickness of the active layer at the outer edge.

[0025] In one embodiment, the active layer comprises a multiple quantum well structure (MQW) including a plurality of barrier layers and a plurality of well layers, and the indium content of the well layer at the center of the cross-section may differ from the indium content of the well layer at the outer edge.

[0026] In one embodiment, the color of light emitted from the active layer at the center of the cross-section may be different from the color of light emitted from the outer edge.

[0027] In one embodiment, the first conductive semiconductor layer may have a trapezoidal cross-sectional shape.

[0028] A light-emitting device according to one embodiment of the present invention may include a semiconductor layer, a support layer supporting the semiconductor layer, a second electrode disposed between the support layer and the semiconductor layer, and a first electrode disposed on the semiconductor layer.

[0029] In one embodiment, the semiconductor layer may include a second conductivity type semiconductor layer disposed on the second electrode and electrically connected to the second electrode, an active layer disposed on the second conductivity type semiconductor layer, and a first conductivity type semiconductor layer disposed on the active layer.

[0030] In one embodiment, the cross-sectional length of the first surface facing the first electrode among the first conductive semiconductor layers may be shorter than the cross-sectional length of the second surface facing the active layer.

[0031] In one embodiment, a first insulating layer may be further included that covers the first conductive semiconductor layer and has an opening (OP) for connecting the first conductive semiconductor layer and the first electrode.

[0032] In one embodiment, the second conductivity type semiconductor layer is a semiconductor layer doped with a P-type dopant, and the width of the second conductivity type semiconductor layer in cross-section may be longer than the width of the first conductivity type semiconductor layer.

[0033] In one embodiment, the cross-sectional width of the first conductive semiconductor layer may narrow as it moves away from the active layer.

[0034] In one embodiment, the semiconductor layers are provided in plurality and spaced apart on a plane, and may further include a cover layer covering the plurality of semiconductor layers.

[0035] In one embodiment, the cover layer may include a plurality of protrusions formed corresponding to each of the plurality of semiconductor layers.

[0036] The present invention can provide a light-emitting device and a light-emitting module including the same, which can suppress local heat generation and improve light-emitting efficiency by optimizing the thickness and cross-sectional shape of the first conductivity semiconductor layer, the active layer, and the second conductivity semiconductor layer of the light-emitting element to improve the current flow and diffusion path.

[0037] The present invention can provide a light-emitting device and a light-emitting module including the same, which can improve light-emitting efficiency and reliability by designing the cross-sectional length of the first surface facing the first electrode of the first conductive semiconductor layer to be shorter than the cross-sectional length of the second surface facing the active layer, thereby inducing the current to be distributed more uniformly throughout the active layer and stabilizing the flow of the current.

[0038] The present invention can provide a light-emitting device and a light-emitting module including the same, which can prevent the problem of current concentration in a specific area and improve current spreading by forming the thickness of the central and outer parts of a first conductive semiconductor layer differently.

[0039] The present invention can provide a light-emitting device and a light-emitting module including the same, which can expand the distribution of emission wavelengths and improve color uniformity by forming a difference in thickness between the central and outer parts and a difference in indium (In) composition within the active layer.

[0040] The present invention can provide a light-emitting device and a light-emitting module including the same, which can expand the current diffusion path and increase the luminous efficiency by extending the cross-sectional length of the surface of a second conductivity type semiconductor layer.

[0041] The present invention can provide a light-emitting device and a light-emitting module including the same, which can induce uniform injection of current and realize stable light-emitting characteristics throughout the light-emitting region by designing the width of an opening formed in an insulating layer above a second conductivity type semiconductor layer to be smaller than the cross-sectional length of a first conductivity type semiconductor layer.

[0042] The present invention can provide a light-emitting device and a light-emitting module including the same, which can improve light-emitting characteristics, light output, and light-emitting uniformity by precisely controlling resistance distribution and current flow by designing a first conductive semiconductor layer in various cross-sectional shapes such as arcuate or trapezoidal.

[0043] FIG. 1 is a cross-sectional view of a light-emitting device according to one embodiment of the present invention.

[0044] Figure 2 is an enlarged view showing the active layer of Figure 1 in enlarged form.

[0045] FIG. 3 is a cross-sectional view of a light-emitting device according to another embodiment of the present invention.

[0046] FIG. 4 is a plan view of a light-emitting device according to another embodiment of the present invention.

[0047] Figure 5 is a cross-sectional view in the direction I-I′ of Figure 4.

[0048] Figure 6 is a cross-sectional view in the direction II-II′ of Figure 4.

[0049] In the following description, numerous specific details are described for the purpose of explanation and to provide a complete understanding of the various embodiments or implementations of the present disclosure. As used herein, “Embodiments” and “Implementations” are interchangeable terms indicating non-limiting examples of devices or methods utilizing one or more of the concepts of the invention disclosed herein. However, it will be apparent that various embodiments may be implemented without utilizing these specific details or by utilizing one or more equivalent arrangements. In other examples, known structures and devices are illustrated in block diagram form to avoid unnecessarily obscuring the various embodiments. Furthermore, while various embodiments may differ from one another, they do not need to be exclusive. For example, specific shapes, configurations, and characteristics of an embodiment may be used or implemented in other embodiments without departing from the scope of the concept of the invention.

[0050] Unless otherwise specified, the illustrated embodiments should be understood as providing exemplary features of varying details in some ways in which the concept of the present invention can actually be realized. Therefore, unless otherwise specified, features, components, modules, layers, membranes, panels, regions and / or modes of various embodiments (hereinafter referred to individually or collectively as “elements”) may be combined, separated, interchanged, and / or rearranged differently without departing from the scope of the concept of the present invention.

[0051] The use of cross-hatching and / or shading in the attached drawings is generally provided to clarify the boundaries between adjacent elements. As such, the presence or absence of cross-hatching or shading, unless otherwise specified, does not imply or indicate any preference or requirement regarding the specific material, material properties, dimensions, proportions, commonalities between the exemplified elements, or any other features, attributes, and characteristics of the elements. Additionally, in the attached drawings, the size and relative size of the elements may be exaggerated for clarity and / or illustrative purposes. When embodiments are implemented differently, specific process sequences may be performed differently from the described order. For example, two consecutively described processes may be performed substantially simultaneously or in an order opposite to the described order. Also, the same reference numerals indicate the same elements.

[0052] When an element such as a layer is referred to as being "on", "connected to," or "coupled to" another element or layer, said element may be directly on, connected to, or coupled to the other element or layer, or an interposed element or layer may exist. However, when an element or layer is referred to as being "directly on", "directly connected to," or "directly coupled to" another element or layer, no interposed element or layer exists. To this end, the term "connected" may refer to a physical, electrical, and / or fluid connection with or without an interposed element. Furthermore, the DR1-axis, DR2-axis, and DR3-axis are not limited to the three axes of an orthogonal coordinate system, such as the x, y, and z axes, and may be interpreted in a broader sense. For example, the DR1-axis, DR2-axis, and DR3-axis may be perpendicular to each other, or they may represent different directions that are not perpendicular to each other. For the purposes of this disclosure, “one or more of X, Y, and Z” and “one or more selected from the group consisting of X, Y, and Z” may be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed articles.

[0053] Although terms such as “first,” “second,” etc., may be used herein to describe various forms of elements, these elements shall not be limited by these terms. These terms are used to distinguish one element from another. Therefore, the first element discussed below may be named the second element without departing from the teachings of the present disclosure.

[0054] Spatially relative terms such as “below,” “under,” “immediately below,” “lower,” “above,” “upper,” “upper,” “higher,” and “side” (e.g., as in “side wall”) may be used for descriptive purposes and thereby to describe the relationship between one element and another element(s) as illustrated in the drawings. Spatially relative terms are intended to include different orientations of the device in use, operation, and / or manufacture in addition to the orientations illustrated in the drawings. For example, if the device in the drawings is inverted, the element described as “below” or “under” another element or feature will be oriented “above” the other element or feature. Therefore, the exemplary term “below” may include both upper and lower orientations. Additionally, the device may be oriented differently (e.g., rotated 90° or oriented in a different orientation), and thus, spatially relative descriptors used herein may also be interpreted accordingly.

[0055] The technical terms used in this specification are intended to describe specific embodiments and are not limiting. The singular form used in this specification also includes the plural form unless the context clearly indicates otherwise. Additionally, the terms “comprising,” “comprising,” “comprising,” and / or “comprising” used in this specification specify the presence of the mentioned features, integers, steps, operations, elements, components, and / or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Furthermore, the terms “substantially,” “about,” and other similar terms used in this specification are used to indicate approximation rather than degree, and are used to describe inherent deviations of measured, calculated, and / or provided values ​​that may be recognized by a person of ordinary knowledge in the art.

[0056] Various embodiments are described below with reference to cross-sectional and / or exploded drawings, which are schematic examples of idealized embodiments and / or intermediate structures. As such, variations from the shapes in the drawings may be expected, for example, as a result of manufacturing techniques and / or tolerances. Therefore, the embodiments disclosed herein should not be interpreted as being limited to the shapes of specific illustrated regions, but should be interpreted to include, for example, deviations in shape resulting from manufacturing. In this way, the regions illustrated in the drawings may be schematic in nature, and the shapes of these regions may not reflect the actual shapes of the regions of the device, and thus are not intended to have a limiting meaning.

[0057] As is customary in the art, some embodiments may be illustrated and described in the accompanying drawings in terms of functional blocks, units, and / or modules. Those skilled in the art will understand that these blocks, units, and / or modules are physically implemented by electronic (or optical) circuits, such as logic circuits, discrete components, microprocessors, wiring circuits, memory elements, and wiring connections, formed using semiconductor-based manufacturing technology or other manufacturing technology. Where blocks, units, and / or modules are implemented by microprocessors or other similar hardware, they may be programmed and controlled using software (e.g., microcode) to perform the various functions discussed herein, and may optionally be driven by firmware and / or software. Additionally, each block, unit, and / or module may be implemented by dedicated hardware, or as a combination of dedicated hardware for performing some functions and a processor for performing other functions (e.g., one or more programmed processors and associated circuits). Additionally, each of the blocks, units, and / or modules of some embodiments may be physically separated into two or more interacting and individual blocks, units, and / or modules without departing from the scope of the concept of the present invention. Additionally, the blocks, units, and / or modules of some embodiments may be physically combined into more complex blocks, units, and / or modules without departing from the scope of the concept of the present invention.

[0058] Unless otherwise defined, all terms used herein (including technical or scientific terms) have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with that meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0059] Hereinafter, the light-emitting device of the present invention and the light-emitting module including the same will be described in detail through the drawings.

[0060] Referring to FIG. 1, a light-emitting device (100) according to one embodiment of the present invention may include a semiconductor layer (120) and a support layer (110) that supports the semiconductor layer (120). Furthermore, it may further include a first electrode (170) disposed between the support layer (110) and the semiconductor layer, and a second electrode (140) disposed on the semiconductor layer (120).

[0061] The support layer (110) is a base for supporting the semiconductor layer (120) and is not limited to a specific type, material, or structure. For example, the support layer (110) may be a support substrate, such as a circuit board, a light-transmitting substrate, a glass substrate, a TFT substrate, a polymer substrate, a flexible substrate, a polyimide substrate, etc. The support layer (110) may be selected according to the application purpose or manufacturing process of the light-emitting device (100), and in particular, if a flexible substrate or a polyimide substrate is used, it may provide a structure suitable for a flexible display or wearable device.

[0062] The support layer (110) may be formed with a larger area than the semiconductor layer (120). The support layer (110) may support a plurality of light-emitting elements or provide an area for forming wiring or electrodes. The support layer (110) may be a single-layer structure or a multi-layer structure in which a plurality of layers having different physical properties are stacked. The support layer (110) may include a material with high thermal conductivity or a material with high mechanical strength to improve the reliability of the light-emitting device (100).

[0063] The semiconductor layer (120) may include a first conductive semiconductor layer (121) disposed on top of a support layer (110), an active layer (122) covering the first conductive semiconductor layer (121), and a second conductive semiconductor layer (123) covering the active layer (122).

[0064] The first conductivity semiconductor layer (121) may include a phosphide or nitride-based semiconductor such as (Al, Ga, In)P or (Al, Ga, In)N. The first conductivity semiconductor layer (121) may be grown using a technology such as MOCVD, MBE, or HVPE.

[0065] The first conductivity type semiconductor layer (121) may be doped as n-type by including one or more impurities such as Si, C, Ge, Sn, Te, Pb, etc. However, it is not limited thereto, and the first conductivity type semiconductor layer (121) may be doped as an opposite conductivity type by including a p-type dopant.

[0066] The active layer (122) may be a light-emitting layer disposed on one side of the first conductivity semiconductor layer (121). The active layer (122) is a light-emitting layer formed on one side of the first conductivity semiconductor layer (121) and may include a phosphide or nitride semiconductor such as (Al, Ga, In)P or (Al, Ga, In)N, and may be grown on the first conductivity semiconductor layer (121) using a technology such as MOCVD, MBE, or HVPE. Additionally, the active layer (122) may include a quantum well structure (QW) comprising at least two barrier layers (122a) and at least one well layer (122b), and furthermore, may include a multiple quantum well structure (MQW) comprising a plurality of barrier layers (122a) and a plurality of well layers (122b). The wavelength of light emitted from the active layer (122) can be controlled by controlling the composition ratio of the material constituting the well layer (122b).

[0067] The second conductivity semiconductor layer (123) may be a semiconductor layer disposed on one side of the active layer (122). The second conductivity semiconductor layer (123) may include a phosphide-based or nitride-based semiconductor such as (Al, Ga, In)P or (Al, Ga, In)N, and may be grown using techniques such as MOCVD, MBE, or HVPE. The second conductivity semiconductor layer (123) may be doped with a conductivity type opposite to that of the first conductivity semiconductor layer (121). For example, the second conductivity semiconductor layer (123) may be doped with a p-type including impurities such as Mg.

[0068] The first electrode (170) is an electrode disposed between the support layer (110) and the first conductive semiconductor layer (121), and the first conductive semiconductor layer (121) can be electrically connected to the first electrode (170).

[0069] The first electrode (170) may be placed on the lower surface of the first conductive semiconductor layer (121) and connected to an external power source. The lower surface of the first conductive semiconductor layer (121) may be the first surface (S1) of the first conductive semiconductor layer (121) facing the first electrode.

[0070] The first electrode (170) can form an ohmic contact with the first conductive semiconductor layer (121) to enable smooth injection of electrons. The first electrode (170) may be a metal having high electrical conductivity and stable junction characteristics with the first conductive semiconductor layer (121), and may be, for example, a single metal such as titanium (Ti), aluminum (Al), nickel (Ni), gold (Au), silver (Ag), platinum (Pt), molybdenum (Mo), chromium (Cr), or an alloy or stacked structure thereof. Additionally, to improve the characteristics of the semiconductor-metal junction, a transparent conductive oxide (ITO, IZO, etc.) may be additionally included, or a reflective film may be included to increase light extraction efficiency.

[0071] The second electrode (140) is an electrode disposed on the semiconductor layer (120), and the second conductive semiconductor layer (123) can be electrically connected to the second electrode (140).

[0072] The second electrode (140) may cover the second conductive semiconductor layer (123). The second electrode (140) may be formed to cover all or part of the second conductive semiconductor layer (123), and may have a mesh structure, a transparent electrode structure, or a reflective electrode structure to ensure uniformity of current distribution.

[0073] The second electrode (140) may also be a metal material with high electrical conductivity, and may be a single metal such as aluminum (Al), silver (Ag), gold (Au), nickel (Ni), or a multilayer film thereof. Alternatively, the second electrode (140) may be a transparent electrode material such as a transparent conductive oxide (ITO, ZnO, IZO, etc.), graphene, or carbon nanotubes (CNT) to increase luminous efficiency.

[0074] Additionally, the second electrode (140) may include a reflective film structure that increases light extraction efficiency by adjusting the reflectance of the electrode, and may also optimize current diffusion characteristics through surface roughness control or micropatterning.

[0075] Referring again to FIG. 1, when the lower surface of the first conductive semiconductor layer (121) in cross-section is the first surface (S1) facing the first electrode (170), the upper surface of the first conductive semiconductor layer (121) facing the active layer (122) may be the second surface (S2).

[0076] Due to the cross-sectional shape of the first conductive semiconductor layer (121) and the structure in which the active layer (122) covers the first conductive semiconductor layer (122), the cross-sectional length of the first surface (S1) may be shorter than the cross-sectional length of the second surface (S2). In other words, the cross-sectional length of the second surface (S2) may be formed to be longer than the cross-sectional length of the first surface (S1).

[0077] As the cross-sectional length of the first surface (S1) is formed narrowly, when electrons are injected from an external power source, the electrons naturally diffuse within the first conductive semiconductor layer (121) and can be transferred to the second surface (S2) facing the active layer (122). Accordingly, the phenomenon of electrons concentrating in a specific area is suppressed, and they can be uniformly distributed across the entire active layer (122) in contact with the second surface (S2).

[0078] In addition, as electrons injected from the first surface (S1) diffuse to the second surface (S2), the electron movement path is lengthened and dispersed, thereby increasing the current spreading effect. Accordingly, the recombination of electrons and holes occurs efficiently across the entire active layer (122), and the luminous efficiency can be improved. Furthermore, the phenomenon of electron flow concentrating in a specific area is reduced, so localized heating can be suppressed, and accordingly, the thermal stability of the light-emitting device (100) is increased and driving reliability can be improved.

[0079] In addition, as electrons are uniformly injected throughout the active layer (122), the emission wavelength within the multiple quantum well (MQW) structure is stably maintained and the color uniformity can be increased.

[0080] The thickness (t) of the first conductive semiconductor layer (121) in cross-section may differ between the center and the outer edge. The thickness (t) of the first conductive semiconductor layer (121) at the center in cross-section may differ from the thickness (t) of the first conductive semiconductor layer (121) at the outer edge. For example, the thickness (t) of the first conductive semiconductor layer (121) may be thicker at the center than at the outer edge.

[0081] Additionally, the thickness of the first conductive semiconductor layer (121) may be maximum at the center of the cross section. That is, when C is a virtual centerline passing through the center of the semiconductor layer (120), the thickness (t) of the first conductive semiconductor layer (121) may have a maximum value b at the centerline C. B may be the vertical distance from the point Q that intersects the centerline C among the second surfaces (S2) of the first conductive semiconductor layer (121) to the first surface (S1) located vertically below Q. Point Q may be the vertex of the first conductive semiconductor layer (121).

[0082] The first conductive semiconductor layer (121) may have various cross-sectional shapes and is not limited to a specific shape. For example, the first conductive semiconductor layer (121) may have an arc-shaped cross-sectional shape. Alternatively, the first conductive semiconductor layer (121) may be formed as a trapezoid, a multi-curved surface having multiple radii of curvature, or an asymmetric surface that is not centroidally symmetric.

[0083] At this time, the angle (Θ) formed by the two line segments connecting the vertex (Q) of the first conductive semiconductor layer (121) on the cross-section and the lower edges (edges of the first surface (S1)) of the first conductive semiconductor layer (121) may be an obtuse angle.

[0084] Additionally, the vertical length b of the first conductive semiconductor layer (121) at the bottom center of the cross-section may be shorter than the length a from the bottom center to the bottom edge. In other words, the length a between the center line (C) and the edge of the first surface (S1) may be longer than the thickness b of the first conductive semiconductor layer (121) at the center line (C).

[0085] The shape of the first conductivity semiconductor layer (121), which is spread out gently in this manner, prevents electrons from concentrating in a specific area and provides a path through which electrons can naturally diffuse sideways as they move from the first surface (S1) to the upper active layer (122). Therefore, electrons do not flow only through a limited vertical path, but can be dispersed and injected over a wide range before reaching the active layer (122). In other words, the dispersion effect can be enhanced by varying the distance electrons travel from the first conductivity semiconductor layer (121) toward the active layer (122).

[0086] Additionally, the first conductivity semiconductor layer (121) has a structure that spreads out in the horizontal direction, so that regions with locally different resistances can be formed while electrons move. Accordingly, electrons can diffuse more efficiently within the first conductivity semiconductor layer (121) and electrons can be injected evenly throughout the active layer (122).

[0087] The shape of the first conductivity semiconductor layer (121) can significantly improve current spreading, thereby enabling efficient electron-hole recombination to occur throughout the active layer (122). Accordingly, the luminous efficiency is improved, and localized heating phenomena that may occur due to electron concentration in specific areas can be suppressed. In addition, as electrons are uniformly distributed in the active layer (122), the color difference of the emitted light is reduced, ensuring color uniformity, and stable luminous characteristics can be maintained even during long-term operation.

[0088] As the first conductive semiconductor layer (121) has an arc-shaped cross-section, the active layer (122) covering the second surface (S2) of the first conductive semiconductor layer (121) may also have a surface shape similar to that of the first conductive semiconductor layer (121).

[0089] Meanwhile, the light-emitting device (100) may further include a first insulating layer (150) that is disposed on the support layer (110) and surrounds the first conductive semiconductor layer (121). At this time, the active layer (122) may cover a part of the first insulating layer (150) and a second surface (S2) of the first conductive semiconductor layer (121).

[0090] The thickness (n) of the active layer (122) in cross-section may differ between the center and the outer edge. The thickness (n) of the active layer (122) in the center of the cross-section may differ from the thickness (n) of the active layer (122) in the outer edge. For example, the thickness (n) of the active layer (122) may be thicker in the center than in the outer edge.

[0091] FIG. 2 shows an enlarged view of the active layer (122), wherein each barrier layer (122a) and well layer (122b) of the active layer (122) may have a curved shape similar to the second surface (S2) of the first conductive semiconductor layer (121). In FIG. 2, the number of pairs of the multiple quantum well structure (MQW) is exemplary and the present invention is not limited thereto.

[0092] Due to the shape of the active layer (122) and the difference in thickness between the center and the outer edge, the composition of the well layer (122b) in the central region including the centerline (C) and the composition in the outer region located far from the centerline (C) may differ. For example, the indium composition at or near the centerline C may be higher than the indium composition in the region located far from the centerline C.

[0093] In other words, the indium content of the well layer (122b) at the center of the cross-section may differ from the indium content of the well layer (122b) at the outer edge. Specifically, the indium content of the well layer (122b) may be higher at the center than at the outer edge. Due to the difference in content of the well layer (122b), the color of light emitted from the active layer (122) at the center of the cross-section may differ from the color of light emitted at the outer edge.

[0094] As a result, light with a wide wavelength range can be emitted from the well layer (122b). Additionally, by varying the current applied to the semiconductor layer (120), the color of the emitted light can be varied over a wider wavelength range. The wavelength of the light emitted from the well layer (122b) can be white light.

[0095] Next, the second conductive semiconductor layer (123) covers the active layer (122), and the second conductive semiconductor layer (123) may have a surface shape similar to that of the active layer (122).

[0096] Accordingly, in cross-section, the length of the surface of the second conductive semiconductor layer (123) may be longer than the length of the second surface (S2).

[0097] When the second conductivity type semiconductor layer (123) is a p-type semiconductor layer, it has a relatively higher resistance than the first conductivity type semiconductor layer (121), and the surface length of the second conductivity type semiconductor layer (123) can be extended to expand the current diffusion path.

[0098] Generally, because the p-type semiconductor layer has low hole mobility and relatively limited current diffusion, the current tends to concentrate in specific parts of the device. However, if the surface length of the second conductivity semiconductor layer (123) is formed to be longer than the second surface (S2), the contact area with the upper second electrode (140) is widened, and a path can be secured through which the current can diffuse along a wider area. Accordingly, holes can be injected more uniformly throughout the active layer (122), and the recombination of electrons and holes within the active layer (122) can be uniformly achieved, thereby improving the luminous efficiency. In addition, localized concentration of current density is alleviated, making heat generation within the device uniform, and consequently, the thermal stability and reliability of the device can be improved.

[0099] Furthermore, this structure can uniformly distribute the contact resistance with the second electrode (140), thereby mitigating current imbalances in the periphery and center of the electrode and stabilizing the current distribution of the entire device. As a result, the variation in luminous intensity is reduced, and uniform brightness and color characteristics can be achieved across the entire luminous surface.

[0100] Additionally, the thickness (m) of the second conductive semiconductor layer (123) in cross-section may differ at the center and at the outer edge. The thickness (m) of the second conductive semiconductor layer (123) at the center in cross-section may differ from the thickness (m) of the second conductive semiconductor layer (123) at the outer edge. For example, the thickness (m) of the second conductive semiconductor layer (123) may be thicker at the center than at the outer edge.

[0101] The surface of the second conductive semiconductor layer (123) may have a curved shape similar to the second surface (S2) of the first conductive semiconductor layer (121).

[0102] Due to the shape of the second conductivity type semiconductor layer (123) and the difference in thickness between the center and the outer edge, the composition or concentration of the second conductivity type dopant in the center region including the center line (C) may differ from the composition or concentration of the second conductivity type dopant in the outer region located far from the center line (C).

[0103] Meanwhile, the light-emitting device (100) may further include a second insulating layer (130) that covers the second conductive semiconductor layer (123) and has an opening (OP) for connecting the second conductive semiconductor layer (123) and the second electrode (140).

[0104] The second insulating layer (130) may be formed from one or more organic or inorganic insulating materials such as silicon oxide (SiO2), silicon nitride (SiN), aluminum oxide (Al2O₃), titanium oxide (TiO2), or polyimide.

[0105] The second insulating layer (130) may completely cover the second conductive semiconductor layer (123) but may include an opening (OP) that is opened only in a portion of the area for electrical connection with the second electrode (140). The opening (OP) may be formed through a selective etching process of the second insulating layer. The opening (OP) exposes a portion of the surface of the second conductive semiconductor layer (123) so that the second electrode is electrically connected through that area. A center line (C) may penetrate the opening (OP).

[0106] In addition, the opening (OP) may be formed as a single opening depending on the light emission characteristics, or it may be formed as an array structure having multiple fine opening patterns. Applying a multiple opening structure allows for more precise control of current distribution and can equalize contact resistance with the electrode.

[0107] In cross-section, the width of the opening (OP) may be smaller than the cross-sectional length of the first surface (S1). By limiting the size of the opening (OP) in this way, the current injected through the second electrode (140) is not concentrated in a narrow area but is instead induced to spread widely along the second conductive semiconductor layer (123). As a result, current spreading is improved, and uniform current injection across the entire active layer (122) can be achieved.

[0108] Next, FIG. 3 illustrates a light-emitting device (200) according to another embodiment of the present invention, and will be described in detail below, focusing on the differences from the light-emitting device (100) of FIG. 1 and FIG. 2.

[0109] The light-emitting device (200) may include a semiconductor layer (220), a support layer (210), a first electrode (270), a second electrode (240), a second insulating layer (230), and a first insulating layer (250).

[0110] The light-emitting device (200) may have a first conductive semiconductor layer (221) that has a trapezoidal cross-sectional shape. As the first conductive semiconductor layer (221) has a trapezoidal cross-sectional shape, the active layer (222) and the second conductive semiconductor layer (223) may also have a trapezoidal cross-sectional shape.

[0111] Similar to the light-emitting device (100) of FIG. 1, with reference to FIG. 3, the cross-sectional length of the first surface (S1) facing the first electrode (270) of the first conductive semiconductor layer (221) may be shorter than the cross-sectional length of the second surface (S2) facing the active layer (222). The cross-sectional length of the second surface (S2) is equal to the sum of the lengths of the surfaces (S21, S23) facing the active layer (222) from both sides of the surface of the first conductive semiconductor layer (221) and the surface (S22) facing the active layer (222) from the top surface.

[0112] Since the light-emitting device (200) above may be configured to be identical or similar to the light-emitting device (100) of FIG. 1 and FIG. 2 except for the cross-sectional shape of the semiconductor layer (220), the second insulating layer (230), and the second electrode (240), the description of the overlapping configuration is omitted.

[0113] Next, FIG. 4 is a plan view showing a light-emitting device (300) according to another embodiment of the present invention. FIG. 5 is a cross-sectional view in the direction I-I′ of FIG. 4, and FIG. 6 is a cross-sectional view in the direction II-II′ of FIG. 4. Hereinafter, the light-emitting device (300) of FIG. 4 to 6 will be described in detail, focusing on the differences from the light-emitting devices (100, 200) of FIG. 1 to 3.

[0114] The light-emitting device (300) may include a semiconductor layer (320), a support layer (310) that supports the semiconductor layer (320), a second electrode (340) disposed between the support layer (310) and the semiconductor layer (320), and a first electrode (350) disposed on the semiconductor layer (320).

[0115] The semiconductor layer (320) can form a single light-emitting cell. The light-emitting cells may be provided in multiple numbers and arranged spaced apart from each other on the support layer (310). The light-emitting cells may be arranged as light-emitting structures in an A×B matrix pattern (A and B are natural numbers) on the support layer (310).

[0116] The support layer (310) is a substrate for arranging light-emitting cells and is not limited to a specific substrate. For example, the support layer (310) may include heterogeneous substrates such as a sapphire substrate, a gallium arsenide substrate, a silicon substrate, a silicon carbide substrate, or a spinel substrate, a TFT, a circuit board, or an IC substrate, and may also include homogeneous substrates such as a gallium nitride substrate or an aluminum nitride substrate. The support layer (310) may include a conductive pattern, and the conductive pattern may be placed on the upper surface of the support layer (310), placed inside the support layer (310), or penetrate the support layer (310).

[0117] The semiconductor layer (320) may be formed protrudingly on the support layer (310). The semiconductor layer (320) may include a second conductivity type semiconductor layer (323) disposed on the second electrode (340) and electrically connected to the second electrode (340), an active layer (322) disposed on the second conductivity type semiconductor layer (323), and a first conductivity type semiconductor layer (321) disposed on the active layer (322).

[0118] Referring to FIGS. 5 and 6, a second conductivity type semiconductor layer (323), an active layer (322), and a first conductivity type semiconductor layer (321) may be sequentially arranged on the support layer (310).

[0119] The first conductive semiconductor layer (321) may have a shape in which the width varies with respect to the thickness direction. For example, the first conductive semiconductor layer (321) may have a shape in which the width of the cross-section gradually narrows as it moves away from the active layer (322). The first conductive semiconductor layer (321) may function as a lens for extracting light to the outside, and accordingly, the light extraction efficiency may be improved.

[0120] An active layer (322) may be disposed between the first conductive semiconductor layer (321) and the support layer (310). Light generated in the active layer (322) may pass through the first conductive semiconductor layer (321) and be emitted to the outside.

[0121] A second conductive semiconductor layer (323) may be disposed between the active layer (322) and the support layer (310). The second conductive semiconductor layer (323) may have a shape in which its width varies in the thickness direction. For example, the second conductive semiconductor layer (323) may have a shape in which its width gradually narrows as it approaches the active layer (322).

[0122] The second conductivity type semiconductor layer (323) may be a semiconductor layer doped with a P-type dopant. In cross-section, the width of the second conductivity type semiconductor layer (323) may be longer than the width of the first conductivity type semiconductor layer (321).

[0123] Additionally, the maximum width of the second conductivity semiconductor layer (323) may be greater than the maximum width of the first conductivity semiconductor layer (321). Also, the maximum thickness of the second conductivity semiconductor layer (323) may be smaller than the maximum thickness of the first conductivity semiconductor layer (321). Accordingly, the resistance of the second conductivity semiconductor layer (323) is lowered, and the driving voltage and heat generation may be reduced.

[0124] The first electrode (350) is an electrode disposed on the semiconductor layer (320) and may be disposed on the first conductive semiconductor layer (321) and electrically connected to the first conductive semiconductor layer (321). The first electrode (350) may be a conductive transparent electrode and, for example, at least one of ITO, ZnO, or IZO. Alternatively, the first electrode (350) may be a metallic material and may be at least one of Au, Ni, Ti, Ag, Pt, Sn, Cu, or Al.

[0125] The first electrode (350) covers the semiconductor layer (320) and extends outward from the semiconductor layer (320) to cover a non-luminous region between the adjacent semiconductor layers (320) or to cover the adjacent semiconductor layers (320). Accordingly, one semiconductor layer (320) and an adjacent semiconductor layer (320) can be electrically connected through the first electrode (350).

[0126] The lower surface of the first electrode (350) between one semiconductor layer (320) and an adjacent semiconductor layer (320) can be positioned lower than the lower surface of the semiconductor layer (320). Accordingly, since the length of the first electrode (350) is increased, it is possible to prevent the first electrode (350) from being short-circuited even if the support layer (310) contracts and expands.

[0127] Meanwhile, the light-emitting device (300) may further include a first insulating layer (330) that covers the first conductive semiconductor layer (321) and has an opening (OP) for connecting the first conductive semiconductor layer (321) and the first electrode (350).

[0128] The first insulating layer (330) is a layer disposed between the first electrode (350) and the semiconductor layer (320), and covers the semiconductor layer (320) and extends outwardly to cover a non-luminous region between the semiconductor layer (320) and an adjacent semiconductor layer (320), and can cover the adjacent semiconductor layer (320).

[0129] The first insulating layer (330) may include an opening (OP) that exposes a portion of the first conductive semiconductor layer (321). The opening (OP) may be positioned at a location corresponding to each semiconductor layer (320), and the number of openings (OP) may be equal to the number of semiconductor layers (320). The first insulating layer (330) may be made of SiO2, TiO2, or SiN x It can be an insulating material such as Al2O3, etc.

[0130] In one semiconductor layer (320), the cross-sectional width of the opening (OP) may be smaller than the maximum width of the semiconductor layer (320) or the cross-sectional length of the first surface (S1) of the first conductive semiconductor layer (321). Thus, excessive electron generation is prevented, thereby preventing leakage current and preventing an increase in resistance.

[0131] The second electrode (340) is an electrode disposed between the support layer (310) and the semiconductor layer (320), and may be disposed below the second conductive semiconductor layer (323) to be electrically connected to the second conductive semiconductor layer (323). Furthermore, the second electrode (340) may be disposed between the second conductive semiconductor layer (323) and the second electrode pad (394) to be described later.

[0132] The second electrode (340) may be a conductive transparent electrode, for example, at least one of ITO, ZnO, or IZO. Alternatively, the second electrode (340) may be a metallic material, and may be at least one of Au, Ni, Ti, Ag, Pt, Sn, Cu, or Al.

[0133] The maximum width of the second electrode (340) may be greater than the maximum width of the second conductive semiconductor layer (323). Therefore, both ends of the second electrode (340) may be arranged to extend outward beyond the semiconductor layer (320). Thus, current diffusion may be improved.

[0134] The second electrode (340) may contain the same material as the first electrode (350).

[0135] Meanwhile, the light-emitting device (700) may further include a first electrode pad (392). The first electrode pad (392) is electrically connected to the first electrode (350) and may be electrically connected to the first conductive semiconductor layer (321). The first electrode pad (392) may be electrically connected to a plurality of semiconductor layers (320). The first electrode pad (392) may be a metallic material and may include at least one of Au, Ni, Ti, Ag, Pt, Sn, Cu, or Al.

[0136] The first electrode pad (392) may be placed in a non-luminous region between the semiconductor layers (320) and may be in the form of a mesh when viewed from above. The first electrode pad (392) may surround the periphery of the semiconductor layers (320).

[0137] The first electrode pad (392) may include an opening that exposes the semiconductor layer (320), and the minimum width of the opening may be greater than the maximum width of the semiconductor layer (320). Accordingly, the loss of emitted light may be reduced. The width of the opening of the first electrode pad (392) may become wider in the thickness direction. Therefore, the side of the opening of the first electrode pad (392) may reflect light and guide the path of light to increase light extraction efficiency. A portion of the first electrode pad (392) placed between adjacent semiconductor layers (320) may include a concave portion that is concave from the central axis.

[0138] The highest point of the first electrode pad (392) may be located higher than the highest point of the semiconductor layer (320). Additionally, the lowest point of the first electrode pad (392) may be located lower than the lowest point of the semiconductor layer (320). Thus, the emission efficiency of light emitted from the side of the semiconductor layer (320) is increased, and light interference between the semiconductor layers (320) can be prevented.

[0139] Additionally, the light-emitting device (300) may further include a second electrode pad (394). The second electrode pad (394) is electrically connected to the second electrode (340) and may be electrically connected to the second conductive semiconductor layer (323).

[0140] The second electrode pad (394) may be provided in plurality, and each second electrode pad (394) may be electrically connected to each semiconductor layer (320). The second electrode pad (394) may be disposed between the semiconductor layer (320) and the support layer (310), and furthermore, the second electrode pad (394) may be disposed between the second electrode (340) and the support layer (310).

[0141] The second electrode pad (394) may be a metallic material and may include at least one material among Au, Ni, Ti, Ag, Pt, Sn, Cu, or Al. When viewed in cross-section, the width of the second electrode pad (394) may gradually decrease in the thickness direction. That is, the width of the lower surface of the second electrode pad (394) facing the support layer (310) may be greater than the width of the upper surface of the second electrode pad (394) facing the semiconductor layer (320). The thickness of the second electrode pad (394) may be thicker than the thickness of the second electrode (340). Therefore, the thermal capacity of the second electrode pad (394) in the lower surface direction of the second electrode pad (392) is increased, thereby increasing heat dissipation performance.

[0142] A second insulating layer (360) may be disposed on the lower portion of the second electrode pad (394). A portion of the lower surface of the second electrode pad (394) may be in contact with the second insulating layer (360), and a portion of the lower surface of the second electrode pad (394) may be in contact with a conductive material. Thus, the semiconductor layer (320) may be electrically connected to a control device such as an external power source or a controller such as an IC chip. The second insulating layer (360) may include an insulating material such as SiO2, TiO2, SiNx, Al2O3, etc.

[0143] The lower surface of the first electrode (350) may be positioned lower than the lower surface of the second electrode (340). Additionally, the upper surface of the second electrode (340) may be positioned higher than the lower surface of the first electrode (350). Thus, the conductive materials can be arranged to overlap horizontally, thereby increasing heat dissipation efficiency.

[0144] The second insulating layer (360) can extend from the lower surface of one semiconductor layer (320) to the lower surface of an adjacent semiconductor layer (320). Thus, the bonding strength between the semiconductor layers (320) can be increased.

[0145] The light-emitting device (300) may further include a cover layer (301). The cover layer may be placed on top of the semiconductor layer (320) and may cover a plurality of semiconductor layers (320).

[0146] The above cover layer (301) can cover the upper surface of the support layer (310). In addition, the first electrode (350), the first electrode pad (392), the second electrode (340), and the second electrode pad (394) can be covered by the cover layer (301).

[0147] The first electrode (350) can be placed between the first insulating layer (330) and the cover layer (301). Thus, by placing the first electrode (350), which has a relatively low refractive index, between the first insulating layer (330), which has a relatively high refractive index, and the cover layer (301), total reflection can be reduced to increase light extraction.

[0148] The above cover layer (301) may have a shape in which the width gradually decreases in the thickness direction, and the upper surface of the cover layer (301) may be a curved surface. Accordingly, the light refraction and light emission efficiency by the cover layer (301) can be increased.

[0149] The thickness of the cover layer (301) may be greater than the thickness of the semiconductor layer (320). Therefore, moisture penetration into the semiconductor layer (320) can be prevented by the thick cover layer (301).

[0150] The above cover layer (301) can fill the concave portion of the first electrode pad (392). Thus, the bonding strength between the cover layer (301) and the first electrode pad (392) can be increased, thereby preventing the cover layer (301) from falling off.

[0151] The cover layer (301) may include a plurality of protrusions formed corresponding to each of the plurality of semiconductor layers. The apex of one protrusion may be positioned within the opening (OP) region of the first insulating layer (330) formed on the corresponding semiconductor layer (320). The protrusion may function as a lens for reflecting or refracting light emitted from the lower semiconductor layer to increase light extraction efficiency.

[0152] Similar to the light-emitting device (100, 200) of FIGS. 1 to 3, the cross-sectional length of the first surface (S1) facing the first electrode (350) of the first conductive semiconductor layer (321) may be shorter than the cross-sectional length of the second surface (S2) facing the active layer (322). Since the light-emitting device (300) may be configured identically or similarly to the light-emitting device (100, 200) of FIGS. 1 to 3, except for the shape and arrangement order of the semiconductor layer (320), the description of the overlapping configuration is omitted.

[0153] The light-emitting module according to an embodiment of the present invention is not limited to specific uses such as lighting, display, or vehicle lighting, and may include one or more light-emitting devices (100, 200, 300). The light-emitting module may additionally include an optical part, a driving circuit, a heat dissipation part, etc.

[0154]

[0155] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art or those with ordinary knowledge in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and technical scope of the invention as described in the claims set forth below.

[0156] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims.

Claims

1. A semiconductor layer, a support layer supporting the semiconductor layer, a first electrode disposed between the support layer and the semiconductor layer, and a second electrode disposed on the semiconductor layer, The semiconductor layer comprises a first conductivity type semiconductor layer disposed on the first electrode and electrically connected to the first electrode, an active layer covering the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer covering the active layer and electrically connected to the second electrode. A light-emitting device in which the cross-sectional length of the first surface facing the first electrode among the first conductive semiconductor layers is shorter than the cross-sectional length of the second surface facing the active layer.

2. In Claim 1, A light-emitting device further comprising a second insulating layer covering the second conductive semiconductor layer and having an opening for connecting the second conductive semiconductor layer and the second electrode.

3. In Claim 2, A light-emitting device in which the width of the opening above is smaller than the cross-sectional length of the first surface.

4. In Claim 1, A light-emitting device further comprising a first insulating layer disposed on the support layer and surrounding the first conductive semiconductor layer.

5. In Claim 1, A light-emitting device in which the thickness of the first conductive semiconductor layer at the center of the cross-section is different from the thickness of the first conductive semiconductor layer at the outer edge.

6. In Claim 5, A light-emitting device in which the thickness of the first conductivity type semiconductor layer is maximum at the center.

7. In Claim 1, The above first conductive semiconductor layer is a light-emitting device having an arc-shaped cross-sectional shape.

8. In Claim 1, A light-emitting device in which the angle formed by two line segments connecting the vertex of the first conductive semiconductor layer and the lower edges of the first conductive semiconductor layer is obtuse.

9. In Claim 1, A light-emitting device in which the vertical length of the first conductive semiconductor layer at the bottom center of the cross-section is shorter than the length from the bottom center to the bottom edge.

10. In Claim 1, A light-emitting device in which the length of the surface of the second conductive semiconductor layer in cross-section is longer than the length of the second surface.

11. In Claim 1, A light-emitting device in which the thickness of the second conductivity type semiconductor layer at the center of the cross-section is different from the thickness of the second conductivity type semiconductor layer at the outer edge.

12. In Claim 1, A light-emitting device in which the thickness of the active layer at the center of the cross-section is different from the thickness of the active layer at the outer edge.

13. In Claim 1, The active layer comprises a multiple quantum well (MQW) structure including a plurality of barrier layers and a plurality of well layers, and A light-emitting device in which the indium content of the well layer at the center of the cross-section is different from the indium content of the well layer at the outer edge.

14. In Claim 1, A light-emitting device in which the color of light emitted from the active layer at the center of the cross-section is different from the color of light emitted from the outer edge.

15. In Claim 1, The above first conductive semiconductor layer is a light-emitting device having a trapezoidal cross-sectional shape.

16. A semiconductor layer, a support layer supporting the semiconductor layer, a second electrode disposed between the support layer and the semiconductor layer, and a first electrode disposed on the semiconductor layer, The semiconductor layer comprises a second conductivity type semiconductor layer disposed on the second electrode and electrically connected to the second electrode, an active layer disposed on the second conductivity type semiconductor layer, and a first conductivity type semiconductor layer disposed on the active layer. A light-emitting device in which the cross-sectional length of the first surface facing the first electrode among the first conductive semiconductor layers is shorter than the cross-sectional length of the second surface facing the active layer.

17. In Claim 16, A light-emitting device further comprising a first insulating layer covering the first conductive semiconductor layer and having an opening (OP) for connecting the first conductive semiconductor layer and the first electrode.

18. In Claim 16, The above second conductivity type semiconductor layer is a semiconductor layer doped with a P-type dopant, and A light-emitting device in which the width of the second conductivity type semiconductor layer in cross-section is longer than the width of the first conductivity type semiconductor layer.

19. In Claim 16, The above-mentioned first conductive semiconductor layer is a light-emitting device in which the width of the cross-section narrows as it moves away from the active layer.

20. In Claim 16, The above semiconductor layers are provided in multiple numbers and arranged spaced apart on a plane, and A light-emitting device further comprising a cover layer covering the plurality of semiconductor layers.

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