Light emitting diode element

Abstract

The invention discloses a light emitting diode element, comprising a semiconductor stack including a first semiconductor layer, a second semiconductor layer, and an active layer formed therebetween; the exposed region is located in the semiconductor stack and includes a side surface and a bottom portion, and the bottom portion includes an upper surface of the first semiconductor layer. A first electrode on the exposed region and electrically connected to the first semiconductor layer, the first electrode including a first pad electrode and a first finger electrode extending from the first pad electrode; a second electrode on and electrically connected to the second semiconductor layer, the second electrode including a second pad electrode; the first current blocking region is positioned below the first electrode and comprises a plurality of island-shaped parts positioned below the first finger electrodes; wherein the shortest distance between the side surface of the exposed region and the plurality of islands is not less than 1 [mu] m, and the plurality of islands include inclined side surfaces.

Description

[0001] This application is a divisional application of a Chinese patent application (Application No. 202110696042.3, Application Date: January 19, 2018, Invention Name: Light-emitting Diode Element). TECHNICAL FIELD

[0002] The present invention relates to a light-emitting element, and more particularly, to a light-emitting element with improved brightness and current spreading. BACKGROUND

[0003] Light-emitting diodes (LEDs) in solid-state light-emitting elements have been widely used in household devices, indicator lights, optoelectronic products, etc. due to their low power consumption, low heat generation, long lifespan, resistance to breakage, small size, fast response speed, and good optoelectronic characteristics, such as stable light-emitting wavelength. With the development of optoelectronic technology, solid-state light-emitting elements have made considerable progress in light-emitting efficiency, operating lifespan, and brightness, and LEDs are expected to become the mainstream of future lighting devices.

[0004] A conventional LED includes a substrate, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer formed on the substrate, and p- and n-electrodes formed on the p- and n-type semiconductor layers, respectively. When a forward bias of a certain value is applied to the LED through the electrodes, holes from the p-type semiconductor layer and electrons from the n-type semiconductor layer combine in the active layer to emit light. However, the electrodes shield the light emitted by the active layer, and the current tends to accumulate and congest in the semiconductor layer near the electrodes. Therefore, an optimized electrode structure is necessary to improve the brightness, light field uniformity, and operating voltage of the LED. SUMMARY

[0005] A light-emitting element includes a first edge, a second edge, a third edge, and a fourth edge, wherein the first edge and the third edge are opposite to each other, and the second edge and the fourth edge are opposite to each other; a substrate; a semiconductor stack on the substrate, the semiconductor stack including a first semiconductor layer, a second semiconductor layer, and an active layer formed therebetween; a first electrode on the first semiconductor layer and electrically connected thereto, including a first pad electrode adjacent to a corner where the first edge and the second edge intersect; and a second electrode on the second semiconductor layer and electrically connected thereto, including a second pad electrode and a second finger electrode extending from the second pad electrode toward the second edge; wherein the first edge and the third edge are longer than the second edge and the fourth edge; and wherein, as viewed from above, the second finger electrode is not parallel to the first edge and the third edge, and the distance between the second finger electrode and the first edge increases as the second finger electrode extends away from the second pad electrode.

[0006] A light emitting device is disclosed, comprising: a semiconductor stack comprising a first semiconductor layer, a second semiconductor layer, and an active layer formed therebetween; an exposed region formed in the semiconductor stack, comprising a bottom, wherein the bottom comprises an upper surface of the first semiconductor layer; a first electrode comprising a first pad electrode on the exposed region and electrically connected to the first semiconductor layer; a second electrode on the second semiconductor layer and electrically connected to the second semiconductor layer, comprising a second pad electrode; and a first current blocking region under the first electrode, comprising a first central region; wherein the first pad electrode contacts the upper surface of the first semiconductor layer outside the first central region; and wherein the first pad electrode comprises a first side surface and the first central region comprises a second side surface, wherein a slope of the first side surface is greater than a slope of the second side surface.

[0007] A light emitting device is disclosed, comprising: a semiconductor stack comprising a first semiconductor layer, a second semiconductor layer, and an active layer formed therebetween; an exposed region formed in the semiconductor stack, comprising a side surface and a bottom, wherein the bottom comprises an upper surface of the first semiconductor layer. A first electrode on the exposed region and electrically connected to the first semiconductor layer, comprising a first pad electrode and a first finger electrode extending from the first pad electrode; a second electrode on the second semiconductor layer and electrically connected to the second semiconductor layer, comprising a second pad electrode; and a first current blocking region under the first electrode, comprising a plurality of island portions under the first finger electrode; wherein a shortest distance between the side surface of the exposed region and the plurality of island portions is not less than 1 μm, and the plurality of island portions comprise an inclined side surface. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figures 1-2E A schematic view of a light emitting device 1 according to a first embodiment of the present application;

[0009] Figures 3A-3C A schematic view of different embodiments of a cross section along the A-A' line of the light emitting device 1 according to the present application, respectively;

[0010] Figures 4A-4C A schematic view of different embodiments of a cross section along the A-A' line of the light emitting device 1 according to the present application, respectively;

[0011] Figure 5 A schematic view of different embodiments of a partial top view of the light emitting device 1 according to the present application;

[0012] Figure 6 A top view of a light emitting device 2 according to a second embodiment of the present application;

[0013] Figure 7 A top view of a light emitting device 3 according to a third embodiment of the present application;

[0014] Figure 8 A top view of a light emitting device according to different embodiments of the present application;

[0015] Figure 9 Schematic plot of current density distribution for the light emitting element of the second embodiment and comparative examples of the present invention;

[0016] Figure 10 Schematic plot of experimental data of light output power and forward voltage for the light emitting element of the embodiments and comparative examples of the present invention;

[0017] Figure 11A Top view of the light emitting element 4 of the fourth embodiment of the present invention;

[0018] Figure 11B Cross-sectional view along the line B-B' in the light emitting element 4 of the fourth embodiment;

[0019] Figure 12 Schematic view of the light emitting device 6 of an embodiment of the present invention;

[0020] Figure 13 Schematic view of the light emitting device 7 of another embodiment of the present invention.

[0021] Legend

[0022] 1-4 Light emitting element

[0023] 6, 7 Light emitting device

[0024] 10 Substrate

[0025] 12 Semiconductor stack

[0026] 121 First semiconductor layer

[0027] 122 Second semiconductor layer

[0028] 123 Active layer

[0029] 18 Transparent conductive layer

[0030] 180, 530 Opening

[0031] 20 First electrode

[0032] 201 First pad electrode

[0033] 202 First finger electrode

[0034] 28 Exposed area

[0035] 30 Second electrode

[0036] 301 Second pad electrode

[0037] 302 Second finger electrode

[0038] 302a first portion

[0039] 302b second portion

[0040] 3021 first connecting portion

[0041] 40 first current blocking region

[0042] 401 first central region

[0043] 402, 501a island

[0044] 50 second current blocking region

[0045] 501 second central region

[0046] 502 extension region

[0047] 504 gap

[0048] 51 carrier

[0049] 511 first conductive pad

[0050] 512 second conductive pad

[0051] 53 insulating portion

[0052] 54 reflective structure

[0053] 602 lamp envelope

[0054] 604 reflector

[0055] 606 carrier portion

[0056] 608 light emitting unit

[0057] 610 light emitting module

[0058] 612 lamp holder

[0059] 614 heat sink

[0060] 616 connecting portion

[0061] 618 electrical connecting element

[0062] C S , C T contour

[0063] C S1 , C S2 , C T1 sub-contour

[0064] W CB1 , W CB2 , W P , WT width

[0065] D, D1, d1-d6 distance

[0066] E1-E4 first-fourth edge

[0067] L1 virtual extension line

[0068] L2 tangent line

[0069] R local area DETAILED DESCRIPTION

[0070] Embodiments of the present application will be described in detail and illustrated in the accompanying drawings, wherein like or similar components have the same reference numbers throughout the various drawings and the specification.

[0071] Figure 1 is a top view of a light emitting element 1 according to a first embodiment of the present application. Figure 2A is Figure 1 is a cross-sectional view of the light emitting element 1 along the A-A' line segment; Figure 2B is a cross-sectional view of the light emitting element 1 along the B-B' line segment; Figure 2C is a cross-sectional view of the light emitting element 1 along the C-C' line segment; Figure 2D is an enlarged view of a local area R of the light emitting element 1; and Figure 2E is a cross-sectional view of the light emitting element 1 along the D-D' line segment.

[0072] As shown in Figure 1 and Figures 2A-2C , the light emitting element 1 includes a substrate 10, a semiconductor stack 12 on the substrate 10, a first and a second current blocking region 40 and 50 on the semiconductor stack 12, a transparent conductive layer 18 on the semiconductor stack 12, a first electrode 20, a second electrode 30, and a protective layer (not shown) having openings exposing the first and second electrodes 20 and 30. The first electrode 20 includes a first pad electrode 201 and a first finger electrode 202 extending from the first pad electrode 201. The second electrode 30 includes a second pad electrode 301 and a second finger electrode 302 extending from the second pad electrode 301.

[0073] As shown in the top view of Figure 1 , the light emitting element 1 includes a first edge E1, a second edge E2, a third edge E3 opposite the first edge E1, and a fourth edge E4 opposite the second edge E1. The first and third edges E1 and E3 are longer than the second and fourth edges E2 and E4.

[0074] The first pad electrode 201 and the second pad electrode 301 are respectively disposed in the regions on both sides of the light emitting element 1 at opposite edges. In one embodiment, the first pad electrode 201 and the second pad electrode 301 are respectively disposed in the regions of the light emitting element 1 near the two opposite edges. In one embodiment, the first pad electrode 201 and the second pad electrode 301 are respectively disposed at the two opposite edges. In another embodiment, either or both of the first pad electrode 201 and the second pad electrode 301 are respectively spaced apart from the two opposite edges by a distance. In one embodiment, the first pad electrode 201 and / or the second pad electrode 301 are respectively disposed in the regions of the light emitting element 1 near the two opposite edges, and wherein the shortest distance between each pad electrode and each edge near the pad electrode is greater than the length of the pad electrode. In one embodiment, the shortest distance between each pad electrode and each edge near the pad electrode is equal to or less than the width of the pad electrode. The first finger electrode 202 extends from the first pad electrode 201 and extends toward the opposite edge from one of the four edges; the second finger electrode 302 extends from the second pad electrode 301 located adjacent to the above-mentioned opposite edge toward the edge where the first pad electrode 201 is located. More specifically, as shown in Figure 1 The first pad electrode 201 is disposed at the second edge E2, and the first finger electrode 202 extends along the second edge E2 and the first edge El and points toward the fourth edge E4. The second pad electrode 301 is disposed near the fourth edge E4 and is located on the midline of the fourth edge. The second finger electrode 302 extends along a direction parallel to the third edge E3 and points toward the second edge E2. In another embodiment, the second pad electrode 301 is disposed between the midline of the fourth edge and the third edge E3 (or the first edge El).

[0075] The substrate 10 can be a growth substrate, including a gallium arsenide (GaAs) substrate for growing gallium indium phosphide (AlGaInP), a sapphire (Al2O3) substrate, a gallium nitride (GaN) substrate, a silicon carbide (SiC) substrate, or an aluminum nitride (AIN) substrate for growing indium gallium nitride (InGaN) or aluminum gallium nitride (AlGaN). The substrate 10 can be a patterned substrate, meaning that the upper surface of the substrate 10, on which the semiconductor stack 12 can be epitaxially grown, can have a patterned structure. Light emitted from the semiconductor stack 12 can be refracted by the patterned structure of the substrate 10, thereby improving the brightness of the light emitting element. In addition, the patterned structure slows down or suppresses the misfit between the substrate 10 and the semiconductor stack 12 due to lattice mismatch, thereby improving the epitaxial quality of the semiconductor stack 12.

[0076] In one embodiment of the present application, the semiconductor stack 12 can be formed on the substrate 10 by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), or ion plating, such as sputtering or evaporation.

[0077] The semiconductor stack 12 includes a first semiconductor layer 121, an active layer 123, and a second semiconductor layer 122 formed in sequence on the substrate 10. In one embodiment of the present application, the first semiconductor layer 121 and the second semiconductor layer 122, such as cladding layers or confinement layers, have different conductive types, electrical properties, polarities, or doping elements for providing electrons or holes. For example, the first semiconductor layer 121 is an n-type semiconductor, and the second semiconductor layer 122 is a p-type semiconductor. The active layer 123 is formed between the first semiconductor layer 121 and the second semiconductor layer 122. Electrons and holes combine in the active layer 123 under current drive, converting electrical energy into optical energy for light emission. The wavelength of light emitted by the light emitting element 1 or the semiconductor stack 12 can be adjusted by changing the physical properties and chemical compositions of one or more layers in the semiconductor stack 12.

[0078] The material of the semiconductor stack 12 includes a III-V semiconductor material of Al x In y Ga (1-x-y) N or Al x In y Ga (1-x-y) P, where 0≤x, y≤l; (x+y)≤l. Depending on the material of the active layer, when the material of the semiconductor stack 12 is of the AlInGaP series, red light with a wavelength between 610 nm and 650 nm or yellow light with a wavelength between 550 nm and 570 nm can be emitted. When the material of the semiconductor stack 12 is of the InGaN series, blue light or deep blue light with a wavelength between 400 nm and 490 nm or green light with a wavelength between 490 nm and 550 nm can be emitted. When the material of the semiconductor stack 12 is of the AlGaN series, UV light with a wavelength between 400 nm and 250 nm can be emitted. The active layer 123 can be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), or a multi-quantum well (MQW). The material of the active layer 123 can be an i-type, p-type, or n-type semiconductor.

[0079] Furthermore, a buffer layer (not shown) can be formed on the upper surface of the substrate 10 before forming the semiconductor stack 12. The buffer layer can also reduce the aforementioned lattice mismatch and suppress dislocations, thereby improving epitaxial quality. The material of the buffer layer includes GaN, AlGaN, or AlN. In one embodiment, the buffer layer includes multiple sublayers (not shown). The sublayers may be made of the same material or different materials. In one embodiment, the buffer layer includes two sublayers. The sublayers are made of the same material, AlN. The first sublayer is grown by sputtering, and the second sublayer is grown by MOCVD. In one embodiment, the buffer layer further includes a third sublayer. The third sublayer is grown by MOCVD, and the growth temperature of the second sublayer is higher or lower than the growth temperature of the third sublayer.

[0080] like Figure 1 and Figure 2B As shown, portions of the second semiconductor layer 122 and the active layer 123 are etched downwards and removed until an upper surface of the first semiconductor layer 121 is exposed, forming an exposure region 28. In the exposure region 28, the sidewalls of the second semiconductor layer 122 and the active layer 123, as well as the upper surface of the first semiconductor layer 121, are exposed. In one embodiment, the exposure region 28 is disposed at and extends along a first edge E1 and a second edge E2. A first electrode 20 is disposed on the exposed upper surface of the first semiconductor layer 121, which is part of the exposure region 28, and forms an electrical connection with the first semiconductor layer 121. A second electrode 30 is disposed on and forms an electrical connection with the second semiconductor layer 122.

[0081] The materials of the first pad electrode 201, the first finger electrode 202, the second pad electrode 301, and the second finger electrode 302 are selected from gold (Au), silver (Ag), copper (Cu), chromium (Cr), aluminum (Al), platinum (Pt), nickel (Ni), titanium (Ti), tin (Sn), rhodium (Rh), and alloys or stacks of the above materials.

[0082] A first current-blocking region 40 is formed between the first electrode 20 and the first semiconductor layer 121, and a second current-blocking region 50 is formed between the second electrode 30 and the second semiconductor layer 122. In one embodiment, the first current-blocking region 40 is formed between the first pad electrode 201 and / or the first finger electrode 202 and the first semiconductor layer 121. The second current-blocking region 50 is formed between the second pad electrode 301 and / or the second finger electrode 302 and the second semiconductor layer 122. When current is injected into the light-emitting element 1 via the first pad electrode 201 and the second pad electrode 301, the current diffuses through the first finger electrode 202 and the second finger electrode 302, and then flows into the transparent conductive layer 18. The first current-blocking region 40 and the second current-blocking region 50 prevent most of the current from being directly injected into the active layer 123 from below the electrodes. That is, the injected current is blocked from flowing downwards into the area below the electrodes.

[0083] In this embodiment, as Figure 1 As shown, the first current blocking region 40 includes a plurality of separate island-shaped portions 402 below the first finger electrode 202. The second current blocking region 50 includes a second central region 501 below the second pad electrode 301 and an extension region 502 extending from the second central region 501 and located below the second finger electrode 302. Near the second pad electrode 301, the second central region 501 blocks the downward flow of current (electrons or holes). The plurality of separate island-shaped portions 402 block the downward flow of current dispersed on the first finger electrode 202, and the current is injected into the first semiconductor layer 121 through the first finger electrode 202 between two adjacent island-shaped portions 402. The current dispersed on the second finger electrode 302 flows into the transparent conductive layer 18 and is blocked from flowing downward by the extension region 502 below the second finger electrode 302, so the current diffuses laterally in the transparent conductive layer 18 and flows uniformly into the semiconductor stack 12.

[0084] In another embodiment, similar to the second current blocking region 50, the first current blocking region 40 further includes a first central region (not shown) below the first pad electrode 201. In one embodiment, the first central region of the first current blocking region 40 may be larger or smaller than the first pad electrode 201. In one embodiment, the first central region is separated from the plurality of island portions 402.

[0085] In another embodiment, the first central region (not shown) of the first current blocking region 40 below the first pad electrode 201 is connected to the island portion 402 closest to the first pad electrode 201.

[0086] In another embodiment, the first current blocking region 40 is included in a first central region (not shown) below the first pad electrode 201, but not in the plurality of island portions 402 below the first finger electrode 202.

[0087] The material of the first current blocking region 40 and the second current blocking region 50 comprises a transparent insulating material such as silicon oxide, silicon nitride, silicon oxynitride, titanium oxide, or aluminum oxide. The structure of the current blocking region can be a single layer, multiple layers, or a repeated and overlapped multi-layer structure such as a distributed Bragg reflector (DBR). The thickness of the first current blocking region 40 and the second current blocking region 50 ranges from 700 to 5000 A. In one embodiment, the thickness of the first current blocking region 40 and the second current blocking region 50 ranges from 700 to 1000 A. In another embodiment, the thickness of the first current blocking region 40 and the second current blocking region 50 ranges from 1000 to 5000 A.

[0088] The transparent conductive layer 18 is formed on the upper surface of the second current blocking region 40 and the second semiconductor layer 122, so that the current injected into the second electrode 30 can be uniformly dispersed by the transparent conductive layer 18 and then flow into the second semiconductor layer 122. Since the transparent conductive layer 18 is disposed on the light emitting surface of the light emitting element 1, it is preferable to select a conductive material having transparent properties. More specifically, the transparent conductive layer 18 can include a thin metal such as gold or nickel. The transparent conductive layer 18 can comprise an oxide selected from a metal such as zinc, indium, tin, etc., such as ZnO, InO, SnO, ITO, IZO, or GZO (gallium-doped zinc oxide).

[0089] As shown in FIG. 2, the second current blocking region 50 has a second central region 501 and a second extension region 502. The second central region 501 is disposed under the second pad electrode 301 and has a width W Figure 1 As shown in FIG. 2, the second current blocking region 50 has a second central region 501 and a second extension region 502. The second central region 501 is disposed under the second pad electrode 301 and has a width W

[0090] In another embodiment, the second extension region 502 of the second current blocking region 50 comprises a plurality of separate islands (not shown).

[0091] As shown in FIG. 2, the second current blocking region 50 has a second central region 501 and a second extension region 502. The second central region 501 is disposed under the second pad electrode 301 and has a width W Figure 2A As shown in FIG. 2, the second current blocking region 50 has a second central region 501 and a second extension region 502. The second central region 501 is disposed under the second pad electrode 301 and has a width W T less than the outer width W CB1 and greater than or equal to the width W CB2This allows the transparent conductive layer 18 to cover the outer surface and upper surface of the second central region 501. The transparent conductive layer 18 covers the upper surface of the second semiconductor layer 122, the extension region 502 of the second current blocking region 50, and the upper surface of the second central region 501. In one embodiment, the width W of the opening 180 of the transparent conductive layer 18 is... T The width W of the opening 503, which is smaller than that of the second central area 501, is... CB2 This allows the transparent conductive layer 18 to fill the opening 503 of the second central region 501.

[0092] like Figure 1 As shown, the width of each island 402 is larger than the width of the first finger electrode 202, and each island 402 does not contact the side surfaces of the second semiconductor layer 122 and the active layer 123 in the exposed region 28. Multiple separate islands 402 are distributed on the first semiconductor layer 121. The first finger electrode 202 is formed on the island 402 and only contacts the first semiconductor layer 121 not covered by the island 402. Therefore, current congestion in a specific region of the semiconductor stack 12 adjacent to the first current blocking region 40 can be prevented; that is, current accumulation in the region near the first finger electrode 202 can be prevented. The spacing between two islands 402 and / or the spacing between the island 402 and the side surface of the exposed region 28 can be designed to improve current spread in the semiconductor stack 12. In one embodiment, as... Figure 2E As shown, the shortest distance S between the island portion 402 and the side surface of the exposed area 28 is not less than 1 μm. The island portion 402 is made of a transparent insulating material. In one embodiment, the side surface of the island portion 402 is inclined to the upper surface of the first semiconductor layer 121 of the exposed area 28, so that the inclined side surface of the island portion 142 facilitates light extraction. In one embodiment, the distance between the two island portions 402 and / or the distance between the island portion 402 and the side surface of the exposed area 28 can be designed to improve light extraction. In one embodiment, when the distance between the island portion 402 and the side surface of the exposed area 28 is not less than 1 μm, light is more easily extracted from the semiconductor stack 12. In one embodiment, the island portion 402 has rounded corners or rounded edges. The rounded corners or rounded edges of the island portion 402 also facilitate light extraction.

[0093] In another embodiment, viewed from above, the first finger electrode 202 and the second finger electrode 302 have different widths. In one embodiment, the first finger electrode 202 is wider than the second finger electrode 302.

[0094] In another embodiment, viewed from above, the extension region 502 of the second current blocking region 50 and the island portion 402 of the first current blocking region 40 have different widths. In one embodiment, the extension region 502 of the second current blocking region 50 is wider than the island portion 402 of the first current blocking region 40.

[0095] With reference to Figure 1 , Figure 2A and Figure 2D , the upper surface of the second semiconductor layer 122 between the fourth edge E4 and the end of the first finger electrode 202 is not covered by the transparent conductive layer 18. In the top view of Figure 1 and Figure 2D , the second semiconductor layer 122 has a contour C S , the contour C S comprising a first sub-contour C S1 adjacent to the first finger electrode 202 and a second sub-contour C S1 connected to the first sub-contour C S2 and adjacent to the first edge E1. In an embodiment, the first sub-contour C S1 is located in the exposed area 28 and is part of the contour of the exposed area 28. In an embodiment, the first sub-contour C S1 is parallel to the first edge E1. The first finger electrode 202 is arranged along the first sub-contour C S1 . A portion of the second sub-contour C S2 faces the end of the first finger electrode 202. Figure 2D The dashed line L1 in S1 represents a virtual extension line extending from the first sub-contour C S2 . In the top view, the upper surface of the second semiconductor layer 122 between the virtual extension line L1 and the second sub-contour C T is not covered by the transparent conductive layer 18.

[0096] In the top view of Figure 1 and Figure 2D , the transparent conductive layer 18 has a contour C T , the contour C T comprising a sub-contour C S1 adjacent to and parallel to the first sub-contour C T1 . In an embodiment, the first sub-contour C S1 is parallel to the sub-contour C T1 and the distance between the contour C S and the contour C T near the second edge E2, the third edge E3 and the fourth edge E4 is substantially the same. The distance D1 between the sub-contour C T1 of the transparent conductive layer 18 and the second sub-contour C S2 of the second semiconductor layer 122 is different from the distance between the sub-contour C S1 and the sub-contour C T1 , or from the distance between the contour C S and the contour C T near the second edge E2, the third edge E3 and the fourth edge E4. In an embodiment, D1 is greater than the distance between the sub-contour C T1The first sub-profile C S1 of the transparent conductive layer 18 is not along the second sub-profile line C T1 of the second semiconductor layer 122. S2

[0097] In one embodiment, as shown in FIG. 2A, the length L of the first finger electrode 202 on the first edge El is greater than half the length of the first edge El. Figure 1

[0098] In another embodiment, the first pad electrode 201 is disposed near a short edge, i.e. the second edge E2. In another embodiment, the first pad electrode 201 can be located at or near a corner of the light emitting element 1. In one embodiment, the first pad electrode 201 is located at or near a corner close to the second edge E2.

[0099] In another embodiment, the area of the transparent conductive layer 18 is less than 93% of the area of the second semiconductor layer 122 as viewed from the top.

[0100] In one embodiment, since the first finger electrode 202 extends on and along the first edge El but does not extend to the fourth edge E4, the current spreading in the semiconductor stack 12 between the fourth edge E4 and the end of the first finger electrode 202 is poor and the current density in this region is lower than in other regions. In this embodiment, the top surface of the second semiconductor layer 122 in the poor current spreading region is not covered by the transparent conductive layer 18, so the current can be confined to the region covered by the transparent conductive layer 18. Therefore, the region covered by the transparent conductive layer 18 has a higher current density and the current usage efficiency is improved. In addition, the transparent conductive layer 18 still has a certain absorption ratio for light of a specific wavelength, and the light emitted from the active layer 123 can be extracted through the region not covered by the transparent conductive layer 18, and the light absorption caused by the transparent conductive layer 18 is reduced, thereby improving the brightness of the light emitting element 1.

[0101] Figures 3A-3C FIGS. 2A to 2D respectively show different embodiments of the cross-section of the light emitting element 1 along the A-A' line according to the present application. Figure 1 FIGS. 2A to 2D respectively show different embodiments of the cross-section of the light emitting element 1 along the A-A' line according to the present application. Figure 3A Further shown is an enlarged view of the partial region R. These different embodiments differ from the first embodiment in the width of the opening 180 of the transparent conductive layer 18.

[0102] In one embodiment, as shown in FIG. 2A, the length L of the first finger electrode 202 on the first edge El is greater than half the length of the first edge El. Figure 3A T In one embodiment, as shown in FIG. 2A, the length L of the first finger electrode 202 on the first edge El is greater than half the length of the first edge El. CB1 ​​​And it is greater than the width W of opening 503. CB2 This allows the transparent conductive layer 18 to cover the outer surface and part of the upper surface of the second central region 501. In one embodiment, the width W T Width W greater than the second pad electrode 301 P This ensures that the transparent conductive layer 18 does not contact the second pad electrode 301. In one embodiment, the width W T Equal to the width W of the second pad electrode 301 P This allows the transparent conductive layer 18 to contact the side surface of the second pad electrode 301. In one embodiment, the distance D between the outer edge of the second central region 501 and the opening 180 is between 1 and 10 μm.

[0103] In one embodiment, such as Figure 3B As shown, the width W of the opening 180 in the transparent conductive layer 18 is... T The width W of the second central region 501 is substantially greater than or equal to that of the second central region 501. CB1 The transparent conductive layer 18 does not contact the side and top surfaces of the second central region 501, or only contacts the side surface of the second central region 501. In another embodiment, such as Figure 3C As shown, the width W of the second pad electrode 301 P The width W of the opening 503 of the second central region 501 is less than or substantially equal to the width of the opening 503. CB2 The second pad electrode 301 does not contact the transparent conductive layer 18 or the upper surface of the second central region 501.

[0104] In one embodiment, the entire bottom region of the second pad electrode 301 contacts the second central region 501 and the second semiconductor layer 122. The adhesion between the second pad electrode 301 and the second current blocking region 50 and / or the second semiconductor layer 122 is greater than the adhesion between the second pad electrode 301 and the transparent conductive layer 18, thus preventing the self-emissive element of the second pad electrode 301 from peeling off. The yield and reliability of the light-emitting element are improved.

[0105] Figures 4A-4C Showing respectively according to the present invention Figure 1 Different embodiments of the light-emitting element 1 along the cross section of line segment A-A'. Figure 4A A magnified view of the local region R is further shown. These different embodiments differ from the first embodiment in that the second central region 501 of the second current blocking region 50 does not have an opening exposing the second semiconductor layer 122.

[0106] In one embodiment, such as Figure 4AAs shown, the width of the opening 180 of the transparent conductive layer 18 is smaller than the width of the second central region 501 and larger than the width of the second pad electrode 301. The transparent conductive layer 18 covers the upper surface of the second semiconductor layer 122, the extended region 502 of the second current blocking region 50, and a partial upper surface of the second central region 501. Because the width of the opening 180 of the transparent conductive layer 18 is larger than the width of the second pad electrode 301, the transparent conductive layer 18 does not contact the second pad electrode 301. In an embodiment, the distance D between the edge of the second central region 501 and the opening 180 is between 1 to 10 μm. Since the entire bottom region of the second pad electrode 301 contacts the second central region 501 of the second current blocking region 50, the adhesion between the second pad electrode 301 and the second current blocking region 50 is greater than the adhesion between the second pad electrode 301 and the transparent conductive layer 18, which prevents the second pad electrode from peeling off from the light emitting element 1. The yield and reliability of the light emitting element 1 are improved. In addition, the transparent conductive layer 18, which does not contact the second pad electrode 301, further prevents current from flowing directly into the second semiconductor layer 122 adjacent to the second pad electrode 301 through the contact between the transparent conductive layer 18 and the second pad electrode 301; that is, only a small amount of light or no light can be emitted from the semiconductor stack 12 near the second pad electrode 301 to be absorbed by the second pad electrode 301, and the current can be more effectively utilized.

[0107] In an embodiment, as shown in FIG. 1 1, the width of the opening 180 of the transparent conductive layer 18 is substantially equal to the width of the second central region 501. The transparent conductive layer 18 does not contact the top surface of the second central region 501 of the second current blocking region 50. In another embodiment, as shown in FIG. 12, the width of the opening 180 of the transparent conductive layer 18 is larger than the width of the second central region 501, and the transparent conductive layer 18 does not contact either the top surface or the side surface of the second central region 501. Figure 4B Figure 4C

[0108] Figure 5 are partial top views of the light emitting element 1 according to different embodiments of the present application, showing different designs of the second electrode 30 and the second current blocking region 50.

[0109] As shown in FIG. 1 1, the width of the opening 180 of the transparent conductive layer 18 is substantially equal to the width of the second central region 501. The transparent conductive layer 18 does not contact the top surface of the second central region 501 of the second current blocking region 50. In another embodiment, as shown in FIG. 12, the width of the opening 180 of the transparent conductive layer 18 is larger than the width of the second central region 501, and the transparent conductive layer 18 does not contact either the top surface or the side surface of the second central region 501. Figure 5 ​​As shown, the second center region 501 and the second pad electrode 301 have different shapes as viewed from the top. The second center region 501 of the second current blocking region 50 includes a plurality of island portions 501a separated from each other by slits 504. The transparent conductive layer 18 covers the extended region 502 and a portion of the second center region 501 of the second current blocking region, and has openings 180 exposing a portion of the top surface of the island portions 501a. In one embodiment, the transparent conductive layer 18 contacts the second semiconductor layer 122 through the slits 504. The second pad electrode 301 is formed on the plurality of island portions 501a and contacts the second semiconductor layer 122 through the slits 504. In one embodiment, the extended region 502 of the second current blocking region 50 is connected to any of the island portions 501a. In another embodiment, the extended region 502 of the second current blocking region 50 is separated from the second center region 501, and the extended region is not connected to any of the island portions 501a.

[0110] In one embodiment, the second finger electrode 302 includes a first connecting portion 3021 extending from the periphery of the second pad electrode 301 and connecting the second pad electrode 301 and another portion of the second finger electrode 302. The first connecting portion 3021 is formed above the second current blocking region 50 and the transparent conductive layer 18. More specifically, a portion of the first connecting portion 3021 is formed outside the openings 180 of the transparent conductive layer 18, and another portion of the first connecting portion 3021 is formed in the openings 180 of the transparent conductive layer 18. The first connecting portion 3021 has a width wider than other portions of the second finger electrode 302. The first connecting portion 3021 has a width smaller than the width of the second pad electrode 301. The first connecting portion 3021 of the second finger electrode 302 has a wider width and a larger area, which allows a higher current to pass through to avoid damage to the light emitting element caused by electrostatic discharge (ESD) or electrical over stress (EOS).

[0111] Figure 6 FIG. 4 shows a top view of a light emitting element according to a second embodiment of the present application.

[0112] As Figure 6As shown, the light emitting element 2 includes a substrate 10, a semiconductor stack 12 on the substrate 10, first and second current blocking regions 40 and 50 on the semiconductor stack 12, a transparent conductive layer 18 on the semiconductor stack 12, a first electrode 20, a second electrode 30, and a protective layer (not shown) having openings exposing the first and second electrodes 20 and 30. The structure of the light emitting element 2 is similar to that of the light emitting element 1 described in the first embodiment. The first pad electrode 201, the first current blocking region 40 including a first central region 401 and a plurality of separate island portions 402, the second pad electrode 301, the transparent conductive layer 18, and the second current blocking region 50 including a second central region 501 and an extension region 502 in the above embodiments are applicable to the light emitting element 2. Differences between the light emitting element 2 and the light emitting element 1 are described below.

[0113] In the present embodiment, the first pad electrode 201 is located at a corner where the first edge El and the second edge E2 intersect. The first current blocking region 40 includes the first central region 401 between the first pad electrode 201 and the first semiconductor layer 121. The first central region 401 has a larger area than the first pad electrode 201, so that the first pad electrode 201 does not substantially contact the first semiconductor layer 121.

[0114] The second finger electrode 302 is not parallel to the first finger electrode 202, the first edge El, and / or the third edge E3. More specifically, the first finger electrode 202 and the second finger electrode 302 each include an overlapping portion, and the overlapping portions of the first finger electrode 202 and the second finger electrode 302 are not parallel. The pitch of the first finger electrode 202 and the second finger electrode 302 varies as the second finger electrode 302 extends toward the first pad electrode 201. In one embodiment, the pitch of the overlapping portions increases as the second finger electrode 302 extends away from the second pad electrode 301. In one embodiment, as shown in FIG. 2, the pitch of the overlapping portions is constant. Figure 6 In one embodiment, the shortest distance dl is between the second finger electrode 302 and the end of the first finger electrode 202. In one embodiment, the distance d2 is the largest pitch of the overlapping portions. In one embodiment, the distance d3 is the shortest distance between the end of the second finger electrode 302 and the contour C S of the second semiconductor layer 122 or the shortest distance between the second finger electrode 302 and the contour C S of the second semiconductor layer 122. In one embodiment, the distance d2 is greater than the distance dl, and the distance d2 is greater than the distance d3. In one embodiment, the distance d3 is less than 90 μm. In another embodiment, the distance d2 is greater than half the length of the second edge E2. The second finger electrode 302 is closer to a sub-contour line C T1The spacing gradually increases as the second finger electrode 302 moves away from the second pad electrode 301.

[0115] Figure 6 The dashed line L2 in the diagram represents the tangent of the second pad electrode 301, which is parallel to and adjacent to the third edge E3. In one embodiment, the end of the second finger electrode 302 does not extend beyond the dashed line L2. This prevents the end of the second finger electrode 302 from getting too close to the contour C of the second semiconductor layer 122 near the third edge E3. S This ensures that the current diffusion between the end of the second finger electrode 302 and the second edge E2 and the third edge E3 is as uniform as the current diffusion in other areas of the light-emitting element 2.

[0116] Figure 7 This shows a top view of the light-emitting element 3 according to a third embodiment of the present invention.

[0117] like Figure 7 As shown, the light-emitting element 3 includes a substrate 10, a semiconductor stack 12 on the substrate 10, first and second current blocking regions 40 and 50 on the semiconductor stack 12, a transparent conductive layer 18 on the semiconductor stack 12, a first electrode 20, a second electrode 30, and a protective layer (not shown) having openings exposing the first electrode 20 and the second electrode 30. The structure of the light-emitting element 3 is similar to that of the light-emitting element in the aforementioned embodiment. The differences between the light-emitting element 3 and the light-emitting element 2 will be described below.

[0118] In this embodiment, the second finger electrode 302 includes a curve. The second finger electrode 302 is not parallel to the first finger electrode 202, the first edge E1, and / or the third edge E3. More specifically, the overlapping portion of the first finger electrode 202 and the second finger electrode 302 is not parallel. The second finger electrode 302 extends from the second pad electrode 301 and curves toward the third edge E3.

[0119] like Figure 7 As shown, distance d1 is the shortest spacing between the overlapping portions. In one embodiment, the shortest spacing d1 is located between the ends of the second finger electrode 302 and the first finger electrode 202. Distance d2 is the maximum spacing between the overlapping portions. Distance d3 is the contour C of the second finger electrode 302 and the second semiconductor layer 122. S The shortest spacing. Distance d4 is the distance between the end of the second finger electrode 302 and the contour C of the second semiconductor layer 122 parallel to the third edge E3. S The shortest spacing. Distance d5 is the shortest spacing between the end of the second finger electrode 302 and the first pad electrode 201. The dashed line L2 represents the tangent of the second pad electrode 301 that is adjacent to and parallel to the third edge E3.

[0120] In one embodiment, distance d2 is greater than distance d1, distance d2 is greater than distance d3, and distance d2 is greater than half the length of the second edge E2. In another embodiment, distance d3 is less than 90 μm. In another embodiment, distances d4 and d5 are substantially the same, such that current diffusion in the region between the first pad electrode 201 and the third edge E3 is as uniform as in other regions, such as the region between the first finger electrode 202 and the second finger electrode 302. In another embodiment, the second finger electrode 302 does not extend beyond the dashed line L2. In one embodiment, the curved portion of the second finger electrode 302 does not extend beyond the dashed line L2.

[0121] Figure 8 This shows a light-emitting element AD according to a variation of the present invention. Figure 8 The structure of the light-emitting element is similar to that in the embodiments described above. To clearly illustrate the electrode layout, in... Figure 8 The first and second current blocking regions are not shown.

[0122] like Figure 8 In the illustrated variation of the light-emitting element AD, the second finger electrode 302 includes a first portion 302a that does not overlap with the first finger electrode 202 and a second portion 302b that overlaps with the first finger electrode 202. In one embodiment, the first portion 302a of the second finger electrode 302 is parallel to the first finger electrode 202, the first edge E1, and / or the third edge E3. In another embodiment, the first portion 302a of the second finger electrode 302 is not parallel to the first finger electrode 202, the first edge E1, or the third edge E3. In one embodiment, the second portion 302b of the second finger electrode 302 is not parallel to the first finger electrode 202, the first edge E1, and / or the third edge E3.

[0123] In light-emitting element A, the second portion 302b of the second finger electrode 302 is linear, and the first portion 302a is parallel to the first edge E1. In variations of light-emitting elements B and C, the second portion 302b of the second finger electrode 302 is curved. In light-emitting element D, the entire second finger electrode 302 is curved. The shortest distance between the end of the second finger electrode 302 and the first finger electrode 202 is greater than the shortest distance between the end of the first finger electrode 202 and the second finger electrode 302.

[0124] Figure 9are schematic diagrams of the top view structure and near field emission intensity images of the light emitting devices according to the second embodiment of the present application and the comparative example. The light emitting elements of the second embodiment and the comparative example have the same size. Each of the light emitting elements is injected with a current of 20 mA to obtain the near field emission intensity images. The near field emission intensity images show the current distribution and current density in the light emitting elements. In order to clearly show the difference in electrode layout between the two light emitting elements, the current blocking region and the transparent conductive layer are not shown in Figure 9 . In Figure 9 , the shading represents the distribution of current and brightness, and the darker shading indicates that the current density and brightness of the region are higher. The region with uniform shading indicates that the current in the region of the light emitting element is uniform.

[0125] As shown in Figure 9 , the light emitting elements in the second embodiment and the comparative example each have a pair of finger electrodes and a pair of pad electrodes. The first and second finger electrodes and the pad electrodes are formed on the first semiconductor layer 121 and the second semiconductor layer 122, respectively. The first semiconductor layer 121 is an n-type semiconductor, and the second semiconductor layer 122 is a p-type semiconductor. Therefore, the first and second finger electrodes are n-side finger electrodes formed on the n-type semiconductor and p-side finger electrodes formed on the p-type semiconductor, respectively, and the first and second pad electrodes are n-side pad electrodes and p-side pad electrodes, respectively. The p-side finger electrodes and the n-side finger electrodes of the light emitting element in the comparative example are parallel to each other. In addition, the distance between the outline of the transparent conductive layer (not shown in the figure) and the outline of the second semiconductor layer is substantially fixed. Referring to the comparative example shown in Figure 9 , the brightness and the current density are relatively high in the local region near the end of the p-side finger electrode. In contrast, the brightness and the current density are relatively low in the region between the end of the p-side pad electrode and the n-side finger electrode. This phenomenon shows that the current tends to gather near the end of the p-side finger electrode, and the current distribution is not uniform.

[0126] Referring to the light emitting element of the second embodiment shown in Figure 9 , the two finger electrodes are not parallel. As in the previous embodiment, the region between the end of the first finger electrode and the fourth edge E4 opposite to the first pad electrode is not covered by the transparent conductive layer. In the second embodiment of the present application, the phenomenon of current gathering can be suppressed, and the uniformity of current spreading is better than that of the comparative example. As the uniformity of current distribution is improved, the power of the light emitting element of the present application is increased. In addition, the uniform current distribution can reduce the local heating caused by current gathering, thereby prolonging the lifetime of the light emitting element.

[0127] Figure 10 shows the light emitting element according to the second embodiment of the present application, the light emitting element according to the Figure 8The light output power (Po) and forward voltage (Vf) of the light emitting element A and the light emitting element of the comparative example are shown in Table 1. Figure 10 In the fourth embodiment, neither the first nor the second current blocking region is shown.

[0128] Referring to Figure 10 the light emitting element of the second embodiment has an output power that is 1.125% greater than that of the comparative example. Figure 8 The light emitting element of the variation example A has an output power that is 0.726% greater and a forward voltage (VF) that is 0.025 V less than those of the comparative example.

[0129] Figure 11A A top view of a light emitting element 4 according to a fourth embodiment of the present application is shown. Figure 11B A cross-sectional view along the B-B' line segment of the light emitting device 4 in FIG. 11 is shown. The light emitting element 4 includes a substrate 10, a semiconductor stack 12 on the substrate 10, a first central region 401 of a first current blocking region and a second current blocking region 50 on the semiconductor stack 12, a transparent conductive layer 18 on the semiconductor stack 12, a first electrode including a first pad electrode 201, a second electrode 30 including a second pad electrode 301 and a second finger electrode 302, and a passivation layer (not shown) having an opening exposing the first pad electrode 201 and the second pad electrode 301. The structure of the light emitting element 4 is similar to that of the second embodiment. The differences between the light emitting element 4 and the light emitting element 2 are described below.

[0130] The first electrode electrically connected to the first semiconductor layer 121 includes a first pad electrode 201 that does not have a finger electrode extending therefrom. The first pad electrode 201 is located at one side of the second edge E2. The one side of the second edge E2 includes several embodiments. In one embodiment, the first pad electrode 201 is located at the second edge E2. In one embodiment, the first pad electrode 201 is located at a corner where the first edge El intersects the second edge E2. In one embodiment, the first pad electrode 201 is located at the second edge E2 and adjacent to a corner where the first edge El and the second edge E2 intersect. The first central region 401 of the first current blocking region is formed between the first semiconductor layer 121 and the first pad electrode 201. The width of the first central region 401 of the first current blocking region is less than the width of the first pad electrode 201, and thus, as shown, the first pad electrode 201 substantially contacts the first semiconductor layer 121 outside the first central region 401. In one embodiment, the profile of the first pad electrode 201 exceeds the profile of the first central region 401 by more than 2 μm. That is, the distance D between the edge of the first pad electrode 201 and the first central region 401 is greater than 2 μm to ensure sufficient contact area between the first pad electrode 201 and the first semiconductor layer 121. In one embodiment, the distance D is between 2 and 15 μm. Figure 11B ​

[0131] The first central region 401 of the first current blocking region under the first pad electrode 201 can prevent current from directly injecting into the semiconductor layer under the pad electrode, so that the current is forced to spread laterally. The light emitting element with the current blocking region has another advantage that light emitted from the active layer 123 can be extracted through the current blocking region, and the brightness of the light emitting element can be improved. However, a larger blocking region means a smaller contact area between the electrode and the semiconductor stack, which can affect the electrical properties of the light emitting element, such as the forward voltage (Vf). The design of the area, position or layout of the current blocking region needs to be balanced according to the brightness and electrical properties of the light emitting element. As shown in the first embodiment, the light emitting element 1 has a first central region 401 larger than the area of the first pad electrode 201, which is beneficial to the brightness improvement. As shown in the fourth embodiment, the semiconductor stack 12 of the light emitting element 4 is smaller than that of the light emitting element 1, and does not have a first finger electrode. The first central region 401 of the light emitting element 4 is set to have an area smaller than the first pad electrode 201, so as to increase the contact area between the first semiconductor layer 121 and the first electrode 20, so that the forward voltage (Vf) can be reduced.

[0132] In an embodiment, the second pad electrode 301 is located at one side of the fourth edge E4. The one side of the fourth edge E4 includes several embodiments. In an embodiment, the first pad electrode 201 is located at the fourth edge E4. In an embodiment, the first pad electrode 201 is located near the fourth edge E4. The second finger electrode 302 extends from the second pad electrode 301 towards the second edge E2 along a direction that is not parallel to the first edge E1 and the third edge E3. The distance between the second finger electrode 302 and the first edge E1 increases as the second finger electrode 302 extends away from the second pad electrode 301. The second finger electrode 302 points to the region where the second edge E2 and the third edge E3 intersect. In this way, the distribution of current in the region between the first pad electrode 201 and the third edge E3 can be as uniform as other regions of the light emitting element 4.

[0133] Figure 12 A light emitting device 6 according to an embodiment of the present application is shown. The light emitting element of any of the above embodiments is mounted on the first conductive pad 511 and the second conductive pad 512 of the carrier 51. The first conductive pad 511 and the second conductive pad 512 are electrically insulated by the insulating portion 53 composed of an insulating material. The light emitting element is fixed on the carrier 51 in a flip-chip manner, and the surface of the growth substrate opposite to the first electrode and the second electrode is upward, serving as a light emitting surface. In order to increase the light extraction efficiency of the light emitting element, a reflective structure 54 can be provided around the light emitting element.

[0134] Figure 13A light emitting device 7 according to another embodiment of the present application is shown. The light emitting device 7 is a light bulb including a lamp housing 602, a reflector 604, a light emitting module 610, a lamp base 612, a heat sink 614, a connecting portion 616, and an electrical connecting element 618. The light emitting module 610 includes a carrier portion 606 and a plurality of light emitting units 608 disposed on the carrier portion 606. The plurality of light emitting units 608 can be any one of the light emitting elements or the light emitting device 6 of the aforementioned embodiments.

[0135] However, the above-described embodiments are merely illustrative of the principles of the present application and the practical effect thereof, and are not intended to limit the present application. Any person skilled in the art of the present application can modify and change the above-described embodiments without departing from the technical principles and spirit of the present application. Therefore, the scope of protection of the present application should be determined by the appended claims.

Claims

1. A light emitting element, comprising: a semiconductor stack comprising a first semiconductor layer, a second semiconductor layer, and an active layer formed therebetween; an exposed region in the semiconductor stack comprising a side surface and a bottom, wherein the bottom comprises an upper surface of the first semiconductor layer; a first electrode on the exposed region and electrically connected to the first semiconductor layer, comprising a first pad electrode and a first finger electrode extending from the first pad electrode; a second electrode on the second semiconductor layer and electrically connected to the second semiconductor layer, comprising a second pad electrode; and a first current blocking region under the first electrode, comprising a plurality of islands under the first finger electrode; wherein a shortest distance between the side surface of the exposed region and any of the plurality of islands is not less than 1 μm; and the plurality of islands comprise a slanted side surface.

2. The light emitting element of claim 1, wherein one of the plurality of islands has a circular arc angle or a circular arc edge.

3. The light emitting element of claim 1, wherein the plurality of islands comprise a first island closest to a tip of the first finger electrode, and a distance between the first island and the tip of the first finger electrode is greater than a shortest distance between any two adjacent islands of the plurality of islands.

4. The light emitting element of claim 1, wherein the first current blocking region further comprises a first central region under the first pad electrode; wherein the first pad electrode contacts the upper surface of the first semiconductor layer outside the first central region; and wherein a distance between an edge of the first pad electrode and the first central region is greater than 2 μm.

5. The light emitting element of claim 1, further comprising: a second current blocking region between the second electrode and the second semiconductor layer, and the second current blocking region comprises a second central region under the second pad electrode; wherein the second central region comprises a plurality of islands and / or the second central region and the second pad electrode have different shapes as viewed from above.

6. The light emitting element of claim 1, wherein: the second electrode further comprises a second finger electrode; the second current blocking region further comprises an extension region under the second finger electrode; and any of the plurality of islands is connected to the extension region.

7. The light emitting element of claim 1, wherein the second electrode further comprises a second finger electrode, and the first finger electrode is wider than the second finger electrode.

8. The light emitting element of claim 1, wherein the second electrode further comprises a second finger electrode, and the first finger electrode is not parallel to the second finger electrode.

9. The light emitting element of claim 1, further comprising: a second current blocking region between the second electrode and the second semiconductor layer, and the second current blocking region comprises a second central region under the second pad electrode; and a transparent conductive layer on the second semiconductor layer, comprising an opening; wherein a width of the opening is greater than a width of the second pad electrode.

10. The light emitting element of claim 9, wherein the opening is on the second central region, and a distance between an edge of the second central region and the opening is between 1 and 10 μm. ​

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