Miniature light-emitting device and display device

Abstract

The invention provides a miniature light-emitting device and a display device. The miniature light-emitting device comprises a P-type semiconductor layer and an N-type semiconductor layer, a first doped region and a second doped region are arranged in the P-type semiconductor layer or the N-type semiconductor layer, and the element doping concentration of the first doped region is larger than that of the second doped region. The element doping concentration of the first doped region may be 5 * 10 < 18 > cm <-3 > to 5 * 10 < 19 > cm <-3 >, and the element doping concentration of the second doped region may be 0 to 1 * 10 < 18 > cm <-3 >. The light-emitting area of the miniature light-emitting device is controlled by arranging the areas with different element doping concentrations in the semiconductor layer, and the problem that the light-emitting efficiency is reduced due to the fact that the size of the miniature light-emitting device is reduced is solved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a micro light-emitting device and a display apparatus. Background Art

[0002] In the field of micro LED display devices, in order to provide appropriate display brightness, such as 500 nits to 1000 nits, it is necessary to control the average emission energy of each LED. However, when the LED is working at a low brightness, the brightness difference between different LEDs is large, which can easily lead to display quality problems such as uneven brightness and image defects in the micro LED display device.

[0003] At present, in order to solve the above problems, a technical solution is usually adopted to reduce the size of the light-emitting diode to reduce the light-emitting area. Although this solution can increase the light-emitting brightness per unit area by reducing the light-emitting area, thereby ensuring the light-emitting efficiency and display uniformity of the micro light-emitting diode display device to a certain extent, the reduction in the size of the light-emitting diode will lead to an increase in its side defects, thereby causing a decrease in light-emitting efficiency.

[0004] Therefore, how to ensure the display uniformity of the display device while avoiding the reduction of luminous efficiency has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The purpose of the present application is to provide a micro light-emitting device and a display device, so as to avoid the decrease of light-emitting efficiency while ensuring the display uniformity of the display device.

[0006] An embodiment of the present application provides a micro-light-emitting device, comprising: a P-type semiconductor layer; and an N-type semiconductor layer; wherein a first doping region and a second doping region are provided in the P-type semiconductor layer and / or the N-type semiconductor layer, and the element doping concentration of a portion of the P-type semiconductor layer and / or the N-type semiconductor layer located in the first doping region is greater than the element doping concentration of a portion located in the second doping region.

[0007] In the above-mentioned micro light-emitting device, the element doping concentration of the portion of the P-type semiconductor layer and / or the N-type semiconductor layer located in the first doping region is 5×10^18cm^-3 to 5×10^19cm^-3.

[0008] In the above-mentioned micro light-emitting device, the element doping concentration of the portion of the P-type semiconductor layer and / or the N-type semiconductor layer located in the second doping region is 0 to 1×10^18 cm^-3.

[0009] In the above micro light emitting device, the area of ​​the first doping region accounts for 5% to 90% of the total area of ​​the micro light emitting device.

[0010] In the above micro light emitting device, the second doped region surrounds the first doped region.

[0011] In the above-mentioned micro light-emitting device, the first doped region is located in the central region of the micro light-emitting device.

[0012] In the above-mentioned micro light-emitting device, the first doped region and the second doped region are arranged in parallel.

[0013] In the above micro light emitting device, at least two of the first doped regions and at least two of the second doped regions are arranged alternately.

[0014] In the above-mentioned micro light-emitting device, when both the P-type semiconductor layer and the N-type semiconductor layer are provided with the first doped region, the first doped region in the P-type semiconductor layer at least partially overlaps with the first doped region in the N-type semiconductor layer in a vertical projection direction.

[0015] An embodiment of the present application further provides a display device comprising a plurality of the above-mentioned micro-light-emitting devices.

[0016] The micro light-emitting device provided in the present application realizes effective control of the light-emitting area by setting a first doping region and a second doping region in a P-type semiconductor layer and / or an N-type semiconductor layer, and making the element doping concentration of the part of the P-type semiconductor layer and / or the N-type semiconductor layer located in the first doping region greater than the element doping concentration of the part located in the second doping region. This is because in semiconductor materials, the higher the element doping concentration, the stronger its conductivity, and the lower the element doping concentration, the worse the conductivity, and the current will preferentially choose a path with good conductivity to flow. Therefore, by forming high and low doping regions in the semiconductor layer, the current can be guided to flow mainly through the first doping region with a higher element doping concentration, thereby limiting the light-emitting area to the first doping region, thereby realizing the control of the light-emitting area.

[0017] The present application uses this element doping concentration control method to limit the light-emitting area, without reducing the physical size of the micro-light-emitting device, avoiding the problem of increased side defects due to the reduction of the device size, thereby overcoming the technical defect of reducing the light-emitting efficiency by reducing the device size in the prior art to control the light-emitting area. At the same time, since the current is mainly concentrated in the first doping area with a higher element doping concentration, the light-emitting area is more concentrated and stable, effectively improving the uniformity problem of the device under low-brightness working state.

[0018] For a display device including a plurality of the above-mentioned micro-light-emitting devices, since each micro-light-emitting device has a stable and controllable light-emitting area and the light-emitting efficiency is guaranteed, the display device can achieve better display uniformity while maintaining a high light-emitting efficiency, thereby significantly improving the display quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a block diagram of a display device provided in this application.

[0020] Figure 2 It is a schematic diagram of a first embodiment of a display device provided in the present application.

[0021] Figure 3 is a schematic diagram of a second embodiment of a display device provided in the present application.

[0022] Figure 4 is a schematic diagram of a third embodiment of a display device provided in the present application.

[0023] Figure 5 It is a schematic diagram of a first embodiment of the shapes of the first doped region and the second doped region of the P-type semiconductor layer and / or the N-type semiconductor layer of the micro light-emitting device in the display device provided by the present application.

[0024] Figure 6 It is a schematic diagram of a first embodiment of the shapes of the first doped region and the second doped region of the P-type semiconductor layer and / or the N-type semiconductor layer of the micro light-emitting device in the display device provided by the present application.

[0025] Figure 7 It is a schematic diagram of a first embodiment of the shapes of the first doped region and the second doped region of the P-type semiconductor layer and / or the N-type semiconductor layer of the micro light-emitting device in the display device provided by the present application. DETAILED DESCRIPTION

[0026] The specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0027] The terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different technical features. The term "plurality" and similar words mean two or more, unless otherwise clearly defined.

[0028] The embodiments of the present application may be combined with each other.

[0029] like Figure 1As shown, the display device provided in the embodiment of the present application includes a display panel, a timing controller, a source driving circuit and a power management chip (the power management chip can be integrated into the same chip with the timing controller). The display panel is a Mini-LED display panel or a Micro-LED display panel.

[0030] The display panel includes a display area and a non-display area. The display area is provided with m×n pixel units PX arranged in an array, where m and n are integers greater than 1. The non-display area is located around the display area and is used to arrange a drive circuit and various signal lines. The display panel also includes a plurality of scan lines SCAN, a plurality of data lines DATA and a gate drive circuit. The plurality of scan lines SCAN extend along a first direction and are arranged along a second direction, and the plurality of data lines DATA extend along a second direction and are arranged along the first direction, and the first direction is perpendicular to the second direction. The gate drive circuit is arranged in the non-display area and is electrically connected to the plurality of scan lines SCAN. The source drive circuit is electrically connected to the plurality of data lines DATA through a flexible circuit board. The timing controller is electrically connected to the gate drive circuit and the source drive circuit, respectively.

[0031] Each pixel unit PX includes a pixel driving circuit and a light-emitting device. The pixel driving circuit includes at least two thin film transistors and a storage capacitor. One of the thin film transistors is used as a switching transistor, and its gate is electrically connected to the corresponding scan line, and its source is electrically connected to the corresponding data line; the other thin film transistor is used as a driving transistor, and its gate is electrically connected to the drain of the switching transistor, the source is electrically connected to the first power supply voltage line, and the drain is electrically connected to the anode of the light-emitting device. One end of the storage capacitor is electrically connected to the gate of the driving transistor, and the other end is electrically connected to the source or drain of the driving transistor. The cathode of the light-emitting device is electrically connected to the second power supply voltage line. When the scan line outputs a high-level scan signal, the switching transistor is turned on, and the data signal on the data line is written to the gate of the driving transistor and the storage capacitor through the switching transistor; when the scan line outputs a low-level scan signal, the switching transistor is turned off, the storage capacitor maintains the voltage of the gate of the driving transistor, and the driving transistor generates a driving current corresponding to the gate voltage to drive the light-emitting device to emit light.

[0032] The gate drive circuit includes n-stage cascaded gate drive units, and each stage of the gate drive unit is electrically connected to a scan line. Under the control of the timing controller, the gate drive unit outputs scan signals in sequence to scan each row of pixel units PX in the display area line by line. Under the control of the timing controller, the source drive circuit generates and outputs data signals according to the image data. The timing controller is used to receive and process externally input image data and timing signals, generate control signals, and transmit image data to the source drive circuit. The power management chip PMIC is used to provide operating voltages for various parts of the display device, including providing a second power supply voltage VSS for the cathode of the light-emitting device, providing a first power supply voltage VDD for the first power supply voltage line, and providing a gate drive voltage VGH / VGL for the gate drive circuit.

[0033] The embodiments of the present application provide a micro light-emitting device and a display device. The micro light-emitting device includes a P-type semiconductor layer SL1 and an N-type semiconductor layer SL2. A first doping region HDA and a second doping region LDA are provided in the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2, and the element doping concentration of the portion of the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2 located in the first doping region HDA is greater than the element doping concentration of the portion located in the second doping region LDA.

[0034] like Figure 2 As shown, the P-type semiconductor layer SL1 is provided with a first doping region HDA and a second doping region LDA, and the N-type semiconductor layer SL2 is not provided with the first doping region HDA and the second doping region LDA; Figure 3 As shown, the N-type semiconductor layer SL2 is provided with a first doping region HDA and a second doping region LDA, and the P-type semiconductor layer SL1 is not provided with a first doping region HDA and a second doping region LDA; Figure 4 As shown, a first doping region HDA and a second doping region LDA are disposed in both the P-type semiconductor layer SL1 and the N-type semiconductor layer SL2 .

[0035] Specifically, the P-type semiconductor layer SL1 is a semiconductor layer having hole conductive properties formed by doping with boron elements, and the doping concentration of the boron element in the portion of the P-type semiconductor layer SL1 located in the first doping area HDA is greater than the doping concentration of the boron element in the portion located in the second doping area LDA. The N-type semiconductor layer SL2 is a semiconductor layer having electron conductive properties formed by doping with phosphorus elements, and the doping concentration of the phosphorus element in the portion of the N-type semiconductor layer SL2 located in the first doping area HDA is greater than the doping concentration of the phosphorus element in the portion located in the second doping area LDA. In semiconductor materials, the higher the element doping concentration, the more conductive particles contained therein, and the stronger the conductivity; the lower the element doping concentration, the worse the conductivity. Therefore, the embodiment of the present application controls the flow direction of the current by controlling the doping area of ​​the P-type semiconductor layer SL1 or the N-type semiconductor layer SL2, thereby controlling the light-emitting area of ​​the micro-light-emitting device. The heavily doped first doping area HDA forms the main current channel, that is, the light-emitting area.

[0036] In the embodiment of the present application, the size of the micro light-emitting device is 20 microns × 20 microns, and the thickness of the P-type semiconductor layer SL1 is 1 micron. A 5 micron × 5 micron first doping area HDA is provided in the central area of ​​the P-type semiconductor layer SL1, and the element doping concentration of the first doping area HDA is 5 × 10^19 cm^-3, while the element doping concentration of the surrounding second doping area LDA is 1 × 10^18 cm^-3. This structure allows most of the current to be concentrated in the first doping area HDA in the center, thereby achieving control of the light-emitting area.

[0037] In an embodiment of the present application, the element doping concentration of the first doping region HDA is in the range of 5×10^18 cm^-3 to 5×10^19 cm^-3, and the element doping concentration of the second doping region LDA is in the range of 0 to 1×10^18 cm^-3. The P-type semiconductor layer SL1 and the N-type semiconductor layer SL2 may be made of semiconductor materials such as gallium nitride or gallium arsenide.

[0038] The shape of the micro-light emitting device is not limited to a rectangle, but can be any shape, and its area is in the range of 1 square micrometer to 10 square millimeters. Figure 5 , Figure 6 and Figure 7 As shown, the first doped region HDA can also be in any shape, such as circular, rectangular, pentagonal, hexagonal, cross, annular, etc., and its area accounts for 5% to 90% of the total area of ​​the micro light-emitting device. When the first doped region HDA is annular, an annular light-emitting region can be formed, which is conducive to improving the uniformity of light emission.

[0039] The micro-light emitting device of the present application can be applied to a display device. In a display device, in order to provide a display brightness of 500 nits to 1000 nits, it is necessary to control the light emitting area of ​​each micro-light emitting device. Through the above-mentioned technical solution of controlling the element doping concentration of different regions in the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2, the light emitting area of ​​the micro-light emitting device can be effectively controlled, avoiding the efficiency loss problem caused by the solution of reducing the size of the micro-light emitting device.

[0040] The technical solution of the present application can be applied to the field of micro light emitting diode display technology. By setting regions with different element doping concentrations in the semiconductor layer to control the light emitting area, both display uniformity and the decrease in light emitting efficiency are ensured.

[0041] An embodiment of the present application provides a display device, including a plurality of micro-light-emitting devices, the micro-light-emitting devices including a P-type semiconductor layer SL1, an N-type semiconductor layer SL2, and an active layer AL (including a plurality of quantum well structures (MQW)) arranged between the P-type semiconductor layer SL1 and the N-type semiconductor layer SL2, wherein a first doping region HDA and a second doping region LDA are arranged in the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2, and an element doping concentration of a portion of the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2 located in the first doping region HDA is greater than an element doping concentration of a portion located in the second doping region LDA.

[0042] The quantum well structure includes multiple periods of barrier layers and well layers to improve the light-emitting efficiency. The barrier layers and well layers can be made of materials such as gallium nitride / indium gallium nitride or gallium arsenide / aluminum gallium arsenic.

[0043] The micro light emitting device further includes a first conductive layer CL1 electrically connected to the P-type semiconductor layer SL1 and a second conductive layer CL2 electrically connected to the N-type semiconductor layer SL2, and the first conductive layer CL1 and the second conductive layer CL2 are used to provide an operating current for the micro light emitting device. The first conductive layer CL1 and the second conductive layer CL2 can be made of metal materials such as gold, silver, aluminum, or transparent conductive oxide materials.

[0044] In the display device, the element doping concentrations of the first doping regions HDA in the plurality of micro light emitting devices are the same.

[0045] As an improvement, in an embodiment of the present application, the first doping regions HDA in micro-light-emitting devices of different colors have different element doping concentrations. For example, the element doping concentration of the first doping region HDA of the red micro-light-emitting device is 5×10^19 cm^-3, the element doping concentration of the first doping region HDA of the green micro-light-emitting device is 4×10^19 cm^-3, and the element doping concentration of the first doping region HDA of the blue micro-light-emitting device is 3×10^19 cm^-3. By setting different first doping region HDA element doping concentrations for micro-light-emitting devices of different colors, the luminous efficiency of micro-light-emitting devices of different colors can be optimized respectively, thereby improving the color display quality of the display device.

[0046] In addition, the element doping concentration of the first doping region HDA of the micro-light-emitting device located in the edge area of ​​the display device is higher than the element doping concentration of the first doping region HDA of the micro-light-emitting device located in the central area of ​​the display device, thereby compensating for the uneven brightness problem caused by the edge effect.

[0047] In the embodiment of the present application, since the driving voltage loss of the micro-light emitting device in the first edge region close to the gate driving circuit and the source driving circuit in the display device is small, and the driving voltage loss of the micro-light emitting device in the second edge region far from the gate driving circuit and the source driving circuit is large, different element doping concentrations can be used for the first doping region HDA of the micro-light emitting devices in different regions. Specifically, the element doping concentration of the first doping region HDA of the micro-light emitting device located in the first edge region is less than the element doping concentration of the first doping region HDA of the micro-light emitting device located in the center region of the display device, and the element doping concentration of the first doping region HDA of the micro-light emitting device located in the center region of the display device is less than the element doping concentration of the first doping region HDA of the micro-light emitting device located in the second edge region.

[0048] In an embodiment of the present application, the element doping concentration of the first doping region HDA in the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2 is differentiated according to the distance between the first edge region of the micro-light-emitting device close to the gate driving circuit and / or the source driving circuit of the display device and the second edge region of the display device far from the gate driving circuit and / or the source driving circuit, that is, the element doping concentration is set according to the position of the micro-light-emitting device. For example, when the gate driving circuit is set on the left side of the display device and the source driving circuit is set on the upper side of the display device, the element doping concentration of the first doping region HDA of the micro-light-emitting device can be gradually increased from the upper left corner to the lower right corner. Specifically, the element doping concentration of the upper left corner area is 2×10^19 cm^-3 to 3×10^19 cm^-3, the element doping concentration of the middle area is 3×10^19 cm^-3 to 4×10^19 cm^-3, and the element doping concentration of the lower right corner area is 4×10^19 cm^-3 to 5×10^19 cm^-3, thereby compensating for the uneven brightness problem caused by the drive voltage loss.

[0049] The brightness of the display device is 500 nits to 1000 nits.

[0050] The first doping region HDA is formed as a light emitting region, and the element doping concentration of the first doping region HDA is used to guide current to mainly flow through the first doping region HDA.

[0051] In the embodiment of the present application, the element doping concentration of the first doping area HDA can be achieved by an ion implantation process, and the element doping concentration can be adjusted by controlling the dose and energy of the ion implantation. The second doping area LDA can be achieved by an epitaxial growth process, and the element doping concentration can be adjusted by controlling the flow rate of the doping gas during the growth process.

[0052] Alternatively, the first doped region HDA can be formed by a selective doping process, firstly forming a mask layer on the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2, then forming an opening corresponding to the first doped region HDA in the mask layer by a photolithography process, and finally performing ion implantation through the opening to form a highly doped first doped region HDA.

[0053] The element doping concentration of a portion of the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2 located in the first doping area HDA is 5×10^18 cm^-3 to 5×10^19 cm^-3.

[0054] The element doping concentration of a portion of the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2 located in the second doping area LDA is 0 to 1×10^18 cm^-3.

[0055] The area of ​​the first doping region HDA accounts for 5% to 90% of the total area of ​​the micro-light emitting device, where the total area refers to the area of ​​the micro-light emitting device in a top view.

[0056] In an embodiment of the present application, when both the P-type semiconductor layer SL1 and the N-type semiconductor layer SL2 are provided with a first doping region HDA, the first doping region HDA of the P-type semiconductor layer SL1 completely overlaps with the first doping region HDA of the N-type semiconductor layer SL2 in the vertical projection direction. This structure can form the shortest current path, which is beneficial to improving the luminous efficiency.

[0057] In the embodiment of the present application, the first doping region HDA of the P-type semiconductor layer SL1 and the first doping region HDA of the N-type semiconductor layer SL2 are partially overlapped or staggered in the vertical projection direction. By adjusting the relative positions of the two first doping regions HDA, the current expansion region can be adjusted, thereby achieving precise control of the shape and size of the light-emitting region.

[0058] In an embodiment of the present application, the first doping region HDA is located in the central region of the micro light-emitting device, that is, the second doping region LDA surrounds the first doping region HDA; or, the first doping region HDA and the second doping region LDA are arranged in parallel.

[0059] In the embodiment of the present application, when the second doping region LDA surrounds the first doping region HDA, the second doping region LDA is in a ring structure. The range of current diffusion can be adjusted by adjusting the width of the ring structure.

[0060] When the first doping region HDA and the second doping region LDA are arranged in parallel, at least two first doping regions HDA and at least two second doping regions LDA adopt a cross-striped layout, that is, at least two first doping regions HDA and at least two second doping regions LDA are alternately arranged to form a plurality of stripes. This structure can form a plurality of parallel light-emitting regions, which is conducive to improving light emission uniformity.

[0061] In the embodiment of the present application, the first doping regions HDA are distributed in an array, and a plurality of first doping regions HDA are separated by second doping regions LDA. This structure can form a dot matrix light emitting region, which is conducive to achieving a more uniform light emitting effect.

[0062] The area of ​​the micro light-emitting device is 1μm^2 to 10mm^2.

[0063] The P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2 include gallium nitride or gallium arsenide.

[0064] An electron blocking layer may be disposed between the P-type semiconductor layer SL1 and the active layer AL, and a hole blocking layer may be disposed between the N-type semiconductor layer SL2 and the active layer AL.

[0065] In the embodiment of the present application, the first conductive layer CL1 and the second conductive layer CL2 include an ohmic contact layer and a metal electrode layer. The ohmic contact layer can be a composite metal layer such as nickel / gold or chromium / gold, and the metal electrode layer can be a metal material such as gold, silver, or aluminum.

[0066] The display device further includes a reflective layer, which is disposed on a side of the first conductive layer CL1 or the second conductive layer CL2 away from the active layer AL. The reflective layer may be made of a metal material with high reflectivity, such as silver or aluminum. The reflective layer is used to reflect light propagating away from the light-emitting direction back to the light-emitting direction to improve light extraction efficiency.

[0067] The display device further includes a distributed Bragg reflector, which is arranged between the active layer AL and the P-type semiconductor layer SL1, or between the active layer AL and the N-type semiconductor layer SL2. The distributed Bragg reflector includes high refractive index layers and low refractive index layers alternately arranged, and the thickness of the high refractive index layers and the low refractive index layers is a quarter wavelength.

[0068] The distributed Bragg reflector device is made of multiple layers of semiconductor materials stacked alternately. The distributed Bragg reflector uses gallium nitride / aluminum gallium nitride as a high / low refractive index layer pair. The refractive index of the gallium nitride layer is about 2.5, and the refractive index of the aluminum gallium nitride layer is about 2.2. Both are wide bandgap semiconductor materials with good transparency in the visible light band. In order to ensure the effective transmission of current, silicon doping can be introduced into the gallium nitride layer with an element doping concentration of 1×10^18 cm^-3 to 1×10^19 cm^-3, and magnesium doping can be introduced into the aluminum gallium nitride layer with an element doping concentration of 5×10^17 cm^-3 to 5×10^18 cm^-3.

[0069] Alternatively, multiple conductive channels are provided in the distributed Bragg reflector device. Specifically, multiple periodically arranged tiny through holes are provided in the distributed Bragg reflector device, the through holes are filled with gallium nitride material, and a relatively high concentration of doping is introduced, for example, magnesium doping is introduced in the P-type region, the element doping concentration is 5×10^19 cm^-3 to 1×10^20 cm^-3, and silicon doping is introduced in the N-type region, the element doping concentration is 5×10^19 cm^-3 to 1×10^20 cm^-3, thereby forming a current channel with high conductivity.

[0070] The display device further includes an encapsulation layer, which covers the plurality of micro-light emitting devices and is used to protect the plurality of micro-light emitting devices. The encapsulation layer can be made of transparent materials such as epoxy resin and silica gel, and the refractive index of the encapsulation layer is between 1.4 and 1.6, which is used to improve the light extraction efficiency.

[0071] The display device further includes a plurality of color conversion layers, which are respectively arranged on the light emission paths of the plurality of micro-light emitting devices. The color conversion layers may include phosphor materials or quantum dot materials, and are used to convert the light emitted by the micro-light emitting devices into light of different colors.

[0072] The display device also includes an optical device, which is arranged on the light emission path of the multiple micro-light-emitting devices. The optical device includes a microlens array, a grating or a holographic optical element, which is used to adjust the emission direction of the light emitted by the multiple micro-light-emitting devices to improve the display effect.

[0073] The display device also includes a heat dissipation device, which is arranged on a side of the substrate of the display device away from the plurality of micro-light-emitting devices and is used to dissipate the heat generated by the plurality of micro-light-emitting devices when they are working. The heat dissipation device includes a heat sink, a heat pipe, and the like.

[0074] The micro light-emitting device provided in the present application realizes effective control of the light-emitting area by setting a first doping area HDA and a second doping area LDA in the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2, and making the element doping concentration of the part located in the first doping area HDA in the P-type semiconductor layer SL1 and / or the N-type semiconductor layer SL2 greater than the element doping concentration of the part located in the second doping area LDA. This is because in semiconductor materials, the higher the element doping concentration, the stronger its conductivity, and the lower the element doping concentration, the worse the conductivity, and the current will preferentially choose a path with good conductivity to flow. Therefore, by forming high and low doping regions in the semiconductor layer, the current can be guided to flow mainly through the first doping area HDA with a higher element doping concentration, thereby limiting the light-emitting area to the first doping area HDA, thereby realizing the control of the light-emitting area.

[0075] The present application uses this element doping concentration control method to limit the light-emitting area, without reducing the physical size of the micro-light-emitting device, avoiding the problem of increased side defects due to the reduction of the device size, thereby overcoming the technical defect of reducing the light-emitting efficiency by reducing the device size in the prior art to control the light-emitting area. At the same time, since the current is mainly concentrated in the first doping area HDA with a higher element doping concentration, the light-emitting area is more concentrated and stable, effectively improving the uniformity problem of the device under low-brightness working state.

[0076] For a display device including a plurality of the above-mentioned micro-light-emitting devices, since each micro-light-emitting device has a stable and controllable light-emitting area and the light-emitting efficiency is guaranteed, the display device can achieve better display uniformity while maintaining a high light-emitting efficiency, thereby significantly improving the display quality.

[0077] The embodiments of the present application are described in detail above, and the contents of this specification should not be construed as limiting the scope of protection of the present application.

Claims

1. A micro light emitting device, characterized in that: include: P-type semiconductor layer; as well as N-type semiconductor layer; Wherein, a first doping region and a second doping region are provided in the P-type semiconductor layer and / or the N-type semiconductor layer, and the element doping concentration of a portion of the P-type semiconductor layer and / or the N-type semiconductor layer located in the first doping region is greater than the element doping concentration of a portion located in the second doping region.

2. The micro light emitting device according to claim 1, characterized in that: The element doping concentration of a portion of the P-type semiconductor layer and / or the N-type semiconductor layer located in the first doping region is 5×10^18 cm^-3 to 5×10^19 cm^-3.

3. The micro light emitting device according to claim 1, characterized in that: The element doping concentration of a portion of the P-type semiconductor layer and / or the N-type semiconductor layer located in the second doping region is 0 to 1×10^18 cm^-3.

4. The micro light emitting device according to claim 1, characterized in that: The area of ​​the first doping region accounts for 5% to 90% of the total area of ​​the micro light emitting device.

5. The micro light emitting device according to claim 1, characterized in that: The second doped region surrounds the first doped region.

6. The micro light emitting device according to claim 5, characterized in that: The first doped region is located in a central region of the micro light emitting device.

7. The micro light emitting device according to claim 1, characterized in that: The first doped region and the second doped region are arranged in parallel.

8. The micro light emitting device according to claim 7, characterized in that: At least two of the first doping regions and at least two of the second doping regions are arranged alternately.

9. The micro light emitting device according to claim 1, characterized in that: When both the P-type semiconductor layer and the N-type semiconductor layer are provided with the first doped region, the first doped region in the P-type semiconductor layer at least partially overlaps with the first doped region in the N-type semiconductor layer in a vertical projection direction.

10. A display device, characterized in that: The device comprises a plurality of micro-light emitting devices according to any one of claims 1 to 9.

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