LED device

Abstract

The invention provides an LED device which comprises a substrate, a buffer layer, an N-type semiconductor, a quantum well active layer, an aperture layer, a P-type semiconductor, a passivation layer and a P-type electrode which are arranged in a stacked mode in the growth direction, the aperture layer comprises a plurality of insulating parts and a plurality of conductor parts, each conductor part is located between every two adjacent insulating parts, and the P-type electrode is located between the N-type semiconductor and the P-type semiconductor. The P-type electrode is arranged on the surface of the passivation layer and makes contact with part of the P-type semiconductor layer, a transmission-type grating structure is further arranged on the light-emitting side of the LED device, the orthographic projection of the transmission-type grating structure on the substrate and the orthographic projection of the conductor part on the substrate at least partially coincide, and the transmission-type grating structure is used for filtering light emitted by the quantum well active layer. Stray light is removed; the stray light emitted by the LED device can be removed, the emitted light color is more uniform, and the lighting effect of the LED device is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor optoelectronics, and particularly to an LED device. Background Art

[0002] An LED (Light Emitting Diode) is a semiconductor device that utilizes the energy released during carrier recombination to form light emission. LED devices have many advantages such as low power consumption, pure chromaticity, long lifespan, small size, fast response time, energy conservation, and environmental protection. However, the existing LED devices have poor light condensation of the emitted light and a large amount of stray light, resulting in poor lighting effects.

[0003] Therefore, there is an urgent need for an LED device to solve the above technical problems. Summary of the Invention

[0004] The purpose of the present invention is to provide an LED device for improving the technical problem of a large amount of stray light in the existing deep ultraviolet light emitting diodes.

[0005] To solve the above technical problems, the present invention provides an LED device, including a substrate, a buffer layer, an N-type semiconductor, a quantum well active layer, an aperture layer, a P-type semiconductor, a passivation layer, and a P-type electrode stacked along the growth direction. The aperture layer includes a plurality of insulating portions and a plurality of conductor portions, each conductor portion being located between two adjacent insulating portions. The P-type electrode is disposed on the surface of the passivation layer and is in contact with a part of the P-type semiconductor; Wherein, a transmissive grating structure is further provided on the light-emitting side of the LED device. The orthographic projection of the transmissive grating structure on the substrate coincides at least partially with the orthographic projection of the conductor portion on the substrate. The transmissive grating structure is used to filter the light emitted by the quantum well active layer to remove stray light.

[0006] Preferably, the reflectivity of the N-type semiconductor is greater than that of the P-type semiconductor.

[0007] Preferably, the transmissive grating structure is located on the surface of the P-type semiconductor away from the substrate, or the transmissive grating structure is located on the surface of the P-type electrode away from the substrate.

[0008] Preferably, the transmissive grating structure is located on the surface of the conductor portion away from the substrate, and the orthographic projection of the transmissive grating structure on the substrate coincides with the orthographic projection of the conductor portion on the substrate.

[0009] Preferably, the LED device further includes a reflective grating structure. The reflective grating structure includes a first patterned layer and a reflective metal layer disposed on the first patterned layer and close to the substrate side. The first patterned layer is formed by patterning the surface of the N-type semiconductor close to the substrate.

[0010] Preferably, the reflectivity of the N-type semiconductor is less than that of the P-type semiconductor.

[0011] Preferably, the transmissive grating structure is located on one surface of the N-type semiconductor substrate, or the transmissive grating structure is located on one surface of the buffer layer substrate. Away from Preferably, the transmissive grating structure is located on one surface of the substrate away from the quantum well active layer. Away from Preferably, the transmissive grating structure is located on one surface of the substrate away from the quantum well active layer.

[0012] Preferably, the transmissive grating structure is located on one surface of the substrate away from the quantum well active layer.

[0013] Preferably, the LED device further includes a reflective grating structure, and the reflective grating structure is located on one surface away from the substrate in any one of the conductor portion, the P-type semiconductor, and the P-type electrode.

[0014] Preferably, the material of the transmissive grating structure is SiO2, and the material of the reflective grating structure is a semiconductor material composed of group III elements and group V elements; the periods of both the transmissive grating structure and the reflective grating structure are 100 - 800 nm, and the depths of both the transmissive grating structure and the reflective grating structure are 50 - 1000 nm.

[0015] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention provides an LED device, including a substrate, a buffer layer, an N-type semiconductor, a quantum well active layer, an aperture layer, a P-type semiconductor, a passivation layer, and a P-type electrode stacked along the growth direction. The aperture layer includes a plurality of insulating portions and a plurality of conductor portions, each conductor portion is located between two adjacent insulating portions, and the P-type electrode is disposed on the surface of the passivation layer and is in contact with a part of the P-type semiconductor. Among them, a transmissive grating structure is further provided on the light-emitting side of the LED device, and the orthographic projection of the transmissive grating structure on the substrate coincides at least partially with the orthographic projection of the conductor portion on the substrate. The transmissive grating structure is used to filter the first light emitted by the quantum well active layer to remove stray light. By providing a transmissive grating structure on the light-emitting side of the LED device, and the orthographic projection of the transmissive grating structure on the substrate coincides at least partially with the orthographic projection of the conductor portion on the substrate, the light emitted by the quantum well active layer is filtered to remove stray light, thereby enhancing the lighting effect of the LED device. Description of the Drawings

[0016] Figure 1 is a schematic cross-sectional structure diagram of the LED device provided in Embodiment 1 of the present invention; Figure 2 is a schematic cross-sectional structure diagram of the LED device provided in Embodiment 2 of the present invention; Figure 3 is a schematic diagram of the relationship curve between the wavelength and the light extraction efficiency of the LED devices provided in the embodiments and comparative examples of the present invention. Detailed Embodiments

[0017] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0018] Now, the technical solutions of the present application will be described in combination with specific embodiments.

[0019] Embodiment 1: Please refer to Figure 1 , Figure 1 which is a schematic cross-sectional structure diagram of the LED device 100 provided in Embodiment 1 of the present invention. Among them, the LED device 100 includes a plurality of light-emitting structures. Each light-emitting structure includes a substrate 101, a buffer layer 102, an N-type semiconductor 103, a quantum well active layer 104, an aperture layer 105, a P-type semiconductor 106, a passivation layer 107, and a P-type electrode 109 stacked along the growth direction. The aperture layer 105 includes a plurality of insulating portions 1052 and a plurality of conductor portions 1051. Each conductor portion 1051 is located between two adjacent insulating portions 1052. The P-type electrode 109 is disposed on the surface of the passivation layer 107 and is in contact with a part of the P-type semiconductor 106. Specifically, a transmissive grating structure 110 is further provided on the light-emitting side of the LED device 100. The orthographic projection of the transmissive grating structure 110 on the substrate 101 coincides at least partially with the orthographic projection of the conductor portion 1051 on the substrate 101. The transmissive grating structure 110 is used to filter the first light emitted by the quantum well active layer 104 to remove stray light.

[0020] In the embodiment of the present invention, since the reflectivity of the N-type semiconductor 103 is greater than that of the P-type semiconductor 106; therefore, the propagation direction of the emitted light in the LED device 100 is from the quantum well active layer 104 to the P-type semiconductor 106. At this time, the LED device 100 is a front-mounted structure.

[0021] In the embodiment of the present invention, the substrate 101 is made of sapphire material. The sapphire material has many advantages: First, the production technology of the sapphire material is mature and the device quality is good; second, the stability of the sapphire is very good and it can be used in the high-temperature growth process; finally, the mechanical strength of the sapphire is high and it is easy to process and clean. Therefore, most processes generally use sapphire as the substrate 101.

[0022] In an embodiment of the present invention, the buffer layer 102 includes a low-temperature buffer layer 102 disposed on the substrate 101 and an aluminum nitride intrinsic layer disposed on the low-temperature buffer layer 102; wherein, the material of the low-temperature buffer layer 102 is aluminum nitride, the growth temperature range thereof is between 400 degrees Celsius and 800 degrees Celsius, and the thickness range thereof is between 10 nm and 50 nm; the aluminum nitride intrinsic layer is aluminum nitride, the growth temperature range thereof is between 1200 degrees Celsius and 1400 degrees Celsius, and the thickness range thereof is between 500 nm and 4000 nm.

[0023] In an embodiment of the present invention, the N-type semiconductor 103 is a multi-layer stacked structure doped with N-type, and each layer of the stacked structure includes a first sub-layer and a second sub-layer stacked from bottom to top. The material of the first sub-layer is Al j Ga 1-j N, and the material of the second sub-layer is Al k Ga 1-k N; Among them, the relationship between j and k satisfies 0 ≤ k < j ≤ 100%, and 50% ≤ j - k ≤ 100%.

[0024] Specifically, when k is equal to 0, the second sub-layer is made of gallium nitride material; when j is equal to 100%, the first sub-layer is made of aluminum nitride material; when k is not equal to 0 and j is not equal to 100%, since the aluminum component content in the second sub-layer is less than that in the first sub-layer, the bandgap width of the second sub-layer is less than that of the first sub-layer, which is beneficial to improving the luminous power of the LED device 100.

[0025] In an embodiment of the present invention, the thickness of the first sub-layer is 0.25λ * n1, and the thickness of the second sub-layer is 0.25λ * n2, where λ is the central wavelength of the light emitted from the quantum well active layer 104, n1 is the average refractive index of the first sub-layer, and n2 is the average refractive index of the second sub-layer; the above design makes each sub-layer in the N-type semiconductor 103 a distributed Bragg reflector, which can further reflect more than 99% of the light that conforms to the central wavelength of the light emitted from the quantum well active layer 104.

[0026] Specifically, the dopant in the N-type semiconductor 103 is an N-type dopant containing Si, which is beneficial to providing a large number of electrons and making the N-type semiconductor 103 reused as the electron injection layer of the LED device 100.

[0027] In an embodiment of the present invention, the doping concentration range of the dopant in the N-type semiconductor 103 is between 1E16 cm -3 to 1E21 cm -3 between. Among them, when the doping concentration of the N-type dopant in the N-type semiconductor 103 is less than 1E16 cm -3When the electron concentration in the N-type semiconductor 103 is small, the ability of the N-type semiconductor 103 to attract holes is weak; when the doping concentration of the N-type dopant in the N-type semiconductor 103 is greater than 1E21 cm -3 When it is, it will cause a large number of defects in the N-type semiconductor 103 due to heavy doping, resulting in a self-compensation effect, which will instead reduce the doping concentration of the N-type dopant in the N-type semiconductor 103.

[0028] In the embodiment of the present invention, the number of layers of the stacked structure in the N-type semiconductor 103 ranges from 20 to 40. Among them, when the number of layers of the stacked structure in the N-type semiconductor 103 is less than 20, the effect of the N-type semiconductor 103 in suppressing stray light that does not conform to the central wavelength of the light emitted by the quantum well active layer 104 is not obvious; when the number of layers of the stacked structure in the N-type semiconductor 103 is greater than 40, it will cause the electron input ability of the LED device 100 to deteriorate.

[0029] In the embodiment of the present invention, the quantum well active layer 104 is disposed on the N-type semiconductor 103, and the growth temperature range of the quantum well active layer 104 is between 900 degrees Celsius and 1200 degrees Celsius.

[0030] Specifically, the quantum well active layer 104 includes at least one well layer and at least two barrier layers arranged alternately, and each well layer is inserted between two adjacent barrier layers; wherein, both the well layer and the barrier layer include AlGaN material, and the total aluminum component content of each well layer is lower than the total aluminum component content of each barrier layer, so as to ensure that the carriers in the quantum well active layer 104 are confined within the well layer.

[0031] Further, the material of the well layer is Al x1 Ga y1 N, the thickness of the well layer is 0.1 nm to 5 nm, where 30% < x1 < 80%, and x1 + y1 = 1; the material of the barrier layer is Al x2 Ga y2 N, the thickness of the barrier layer is 1 nm to 30 nm, where 40% < x2 < 90%, and x2 + y2 = 1.

[0032] Further, the number of periods of the quantum well active layer 104 is greater than or equal to 1 and less than or equal to 20, and the number of periods is a positive integer.

[0033] In the embodiment of the present invention, the aperture layer 105 includes a plurality of insulating portions 1052 and a plurality of conductor portions 1051, and each conductor portion 1051 is located between two adjacent insulating portions 1052; wherein, the insulating portion 1052 is SiO2 or SiNFor insulating materials such as these, the conductor portion 1051 can be composed of semiconductor materials such as group III-V element compounds. Specifically, since no current passes through the insulating portion 1052, most of the emitted light from the active layer is transmitted through the conductor portion 1051.

[0034] In an embodiment of the present invention, the P-type semiconductor 106 is a P-type doped multi-layer stacked structure, and each layer of the stacked structure includes a third sub-layer and a fourth sub-layer stacked from bottom to top. The material of the third sub-layer is Al x Ga 1-x N, and the material of the fourth sub-layer is Al y Ga 1-y N; Among them, the relationship between x and y satisfies 0 ≤ y < x ≤ 100%, and 50% ≤ x - y ≤ 100%.

[0035] In an embodiment of the present invention, the thickness of the third sub-layer is 0.25λ * n3, and the thickness of the fourth sub-layer is 0.25λ * n4, where λ is the central wavelength of the light emitted from the quantum well active layer 104, n3 is the average refractive index of the third sub-layer, and n4 is the average refractive index of the fourth sub-layer.

[0036] Specifically, the dopant in the P-type semiconductor 106 is a Mg-containing P-type dopant, which is beneficial for providing a large number of holes and enabling the P-type semiconductor 106 to be reused as the hole injection layer of the LED device 100.

[0037] In an embodiment of the present invention, the doping concentration range of the dopant in the P-type semiconductor 106 is between 1E16 cm -3 and 1E21 cm -3 ; the number of layers of the stacked structure in the P-type semiconductor 106 ranges between 20 and 40.

[0038] In an embodiment of the present invention, a stepped structure is formed between the N-type semiconductor 103 and the quantum well active layer 104, and the area of the N-type semiconductor 103 is larger than the area of the quantum well active layer 104; this setting is for facilitating the deposition of the electrode structure of the LED device 100.

[0039] In an embodiment of the present invention, the passivation layer 107 is disposed on the P-type semiconductor 106 and extends to the surface of the N-type semiconductor 103 through the side surface of the stepped structure; the material of the passivation layer 107 is silicon oxide or silicon nitride, and the passivation layer 107 mainly functions to seal and insulate, preventing external dust and impurities from entering the interior of the LED device 100 and ensuring the normal operation of the LED device 100.

[0040] Specifically, the LED device 100 further includes an N-type electrode 108 and a P-type electrode 109 (transmission grating) respectively disposed on the passivation layer 107; wherein, the P-type electrode 109 is in contact with the P-type semiconductor 106 through a first via hole on the passivation layer 107, and the N-type electrode is in contact with the N-type semiconductor 103 through a second via hole on the passivation layer 107.

[0041] Furthermore, the materials of the N-type electrode and the P-type electrode 109 are each selected from at least one of Rh, Al, Ag, Cr, Ti, Pt, Pd, Au, and Ni.

[0042] In the embodiment of the present invention, a transmission grating structure 110 is further provided on the light-emitting side of the LED device 100. The orthographic projection of the transmission grating structure 110 on the substrate 101 coincides at least partially with the orthographic projection of the conductor portion 1051 on the substrate 101. The transmission grating structure 110 is used to filter the first light emitted by the quantum well active layer 104 to emit a second light with a wavelength of 10-800 nm (ultraviolet and visible light wavelength range) and Spectral broadband narrower.

[0043] Please refer to Figure 1 , the transmission grating structure 110 is located on the surface of the P-type electrode 109 away from the substrate 101; the transmission grating structure 110 is processed on a silica glass material by using a dry etching technique or a nanoimprinting technique.

[0044] Specifically, the number of periods of the transmission grating structure 110 is 100 - 800 nm , the depth of the transmission grating structure 110 is 50-1000 nm; the refractive index of the transmission grating structure 110 is between the refractive index of the P-type semiconductor 106 and the refractive index of air.

[0045] Specifically, when the light emitted by the quantum well active layer 104 radiates upward, after passing through the transmission grating structure 110, the stray light is filtered out, and only the second light remains; the grating equation of the transmission grating structure 110 in an air medium is as follows: Λsinθ = kλ0, where Λ is the period of the grating, θ is the diffraction angle, λ0 is the wavelength of the light, and k is the spectral line order.

[0046] Therefore, according to the above grating equation, when parallel light is perpendicularly incident on the transmission grating structure 110, θ is 90°, λ0 is 100 - 800 nm , and at this time, the grating period of the transmission grating structure 110 is 100 - 800 nm .

[0047] Furthermore, both the period and depth of the transmissive grating structure 110 affect the light extraction efficiency of the LED device 100; the relevant parameters (period, depth, full width at half maximum, duty cycle, etc.) of the transmissive grating structure 110 are optimized by the finite-difference time-domain method to obtain the optimal result parameters, so as to achieve a high light extraction efficiency of the LED device 100 throughout the working wavelength band.

[0048] Preferably, the transmissive grating structure 110 is located on the surface of the P-type semiconductor 106 away from the substrate 101; at this time, the transmissive grating structure 110 is formed by dry etching on the surface of the P-type semiconductor 106 away from the substrate 101.

[0049] Preferably, the transmissive grating structure 110 is located on the surface of the conductor portion 1051 away from the substrate 101, and the orthographic projection of the transmissive grating structure 110 on the substrate 101 coincides with the orthographic projection of the conductor portion 1051 on the substrate 101; at this time, the preparation process of the transmissive grating structure 110 is as follows: First, a transmissive insulating layer is deposited on the surface of the conductor portion 1051 away from the substrate 101, and then a transmissive metal layer is evaporated on the side away from the substrate 101 of the transmissive insulating layer. The transmissive insulating layer and the transmissive metal layer form the transmissive grating structure 110; wherein, the material of the transmissive insulating layer is preferably SiO2, and the material of the transmissive metal layer is preferably indium tin oxide. Please continue to refer to Figure 1 The LED device 100 further includes a reflective grating structure 111. The reflective grating structure 111 is located on the surface of the N-type semiconductor 103 close to the substrate 101. The reflective grating structure 111 is used to reflect the light emitted from the quantum well active layer 104 towards the substrate 101 back, and emit it from the side of the quantum well active layer 104 away from the substrate 101, further increasing the brightness of the emitted light emitted by the LED device 100.

[0050] Specifically, the material of the reflective grating structure 111 is a semiconductor material composed of group III elements and group V elements; the number of periods of both the transmissive grating structure 110 and the reflective grating structure 111 is 100 - 800 nm, and the depth of both the transmissive grating structure 110 and the reflective grating structure 111 is 50 - 1000 nm.

[0051] In this embodiment, the preparation process of the reflective grating structure 111 is as follows: The lower surface of the N-type semiconductor 103 is patterned by a dry etching process to obtain a first reflective pattern layer, and then a metal reflective layer is evaporated on the side of the first reflective pattern layer away from the N-type semiconductor 103. The first reflective pattern layer and the reflective metal layer form the reflective grating structure 111; wherein, the material of the first reflective pattern layer is the same as that of the N-type semiconductor 103, and the material of the first reflective metal layer is preferably aluminum.

[0052] Embodiment 2: Please refer to Figure 2 , Figure 2 , which is a schematic cross-sectional structure diagram of the LED device 100 provided in Embodiment 2 of the present invention. Among them, the structure of the LED device 100 provided in Embodiment 2 of the present invention is substantially the same as that of the LED device 100 provided in Embodiment 1 of the present invention. The difference lies only in the different positions of the transmissive grating structure 110 and the reflective grating structure 111.

[0053] Specifically, in the embodiment of the present invention, the reflectivity of the N-type semiconductor 103 is less than that of the P-type semiconductor 106, so that the propagation direction of the emitted light in the LED device 100 is from the quantum well active layer 104 to the N-type semiconductor 103 (emitting downward). At this time, the LED device 100 belongs to a flip-chip structure. The transmissive grating structure 110 is located on the surface of the N-type semiconductor 103 close to the substrate 101, and the reflective grating structure 111 is located on the surface of the P-type semiconductor 106 far from the substrate 101, as Figure 2 shown. Among them, the preparation process of the transmissive grating structure 110 is as follows: The lower surface of the N-type semiconductor 103 is patterned by a dry etching process to obtain the transmissive grating structure 110. In one embodiment, the transmissive grating structure 110 is located on the surface of the buffer layer 102 far from the substrate 101.

[0054] In another embodiment, the transmissive grating structure 110 is located on the surface of the substrate 101 Close to on one side of the quantum well active layer 104. In still another embodiment, the reflective grating structure 111 is located on the surface of any one of the conductor portion 1051 and the P-type electrode 109 far from the substrate 101.

[0055] Specifically, considering that the reflective grating structure 111 is a metal grating structure, the reflective grating structure 111 can also be disposed above the P-type semiconductor 106 and located on the surface of the P-type electrode 109 far from the substrate 101. Here, the reflective grating structure 111 can either be reused as the P-type electrode 109 or act as a grating to filter light.

[0056] In one embodiment, the preparation process of the reflective grating structure 111 is as follows: The upper surface of the P-type semiconductor 106 is patterned through a dry etching process to obtain a second reflective pattern layer. Then, a second reflective metal layer is deposited on the upper surface of the second reflective pattern layer. The second reflective pattern layer and the second reflective metal layer constitute the reflective grating structure 111. Among them, the material of the second reflective pattern layer is the same as that of the P-type semiconductor 106, and the material of the second reflective metal layer is preferably silver. In multiple embodiments of the present invention, according to different specific uses, the initial wavelengths radiated by different LED devices 100 are different, and the target wavelengths they need to radiate are also different. Specifically, when the initial light emitted by the LED device 100 is light in the UVC band (wavelength range: 200 - 280 nm), the wavelength range of the light finally filtered by the transmissive grating structure 110 is 270 - 280 nm, preferably 275 nm. When the initial light emitted by the LED device 100 is light in the UVB band (280 - 320 nm), the wavelength range of the light finally filtered by the transmissive grating structure 110 is 290 - 300 nm, preferably 300 nm. When the initial light emitted by the LED device 100 is light in the UVA band (320 - 400 nm), the wavelength range of the light finally filtered by the transmissive grating structure 110 is 340 - 350 nm, preferably 350 nm. When the initial light emitted by the LED device 100 is light in the visible light band (400 - 800 nm), the wavelength range of the light finally filtered by the transmissive grating structure 110 is 410 - 430 nm (blue light, with a sterilization effect), preferably 420 nm.

[0057] Please refer to Figure 3 , Figure 3 which is a schematic diagram of the relationship curve between the wavelength and the light extraction efficiency of the LED device 100 provided by the embodiments and comparative examples of the present invention (the abscissa is the initial wavelength, unit: nm; the ordinate is the light extraction efficiency). Among them, the transmissive grating structure 110, the aperture layer 105, and the reflective grating structure 111 are not provided on the light-emitting side of the LED device 100 provided by the comparative example; from Figure 3It can be seen that the light extraction efficiency of the LED device 100 provided in the embodiment of the present invention within the initial wavelength range of a~b is greater than that of the LED device 100 provided in the comparative example within the initial wavelength range of a~b, where 410nm < a < 420nm and 420nm < b < 430nm; this is because when the LED device 100 provided in the embodiment of the present invention emits light with an initial wavelength of 400~440nm, after being focused and filtered by the transmissive grating structure 110, the light extraction efficiency is greatly improved within the wavelength range of a~b (the light extraction efficiency is the largest at about 420nm), and the spectral width becomes smaller (the spectral width changes from 400~440nm to 410~430nm), and the stray light is greatly reduced; at this time, in addition to being able to radiate light with a target wavelength of high brightness, the LED device 100 can also achieve high optical power output.

[0058] For the existing LED device 100, due to the large refractive index difference between the epitaxial structure of the LED device 100 and the refractive index of air, total internal reflection is likely to occur at the interface between the epitaxial structure and air, resulting in a very low external quantum efficiency, which greatly limits the output power of the LED device 100. The present invention introduces a micro-nano grating structure at the interface between the epitaxial structure and air, which can reduce the refractive index difference between the light-emitting interface materials, increase the total internal reflection angle, and reduce light loss; more importantly, the micro-nano grating structure can filter light of a specific wavelength, while light of other wavelengths is scattered and does not pass through, so that light of a specific wavelength can be extracted from the LED device 100, thereby solving the color difference problem of the LED device 100 and obtaining a monochromatic tunable LED device 100 with high brightness and low stray light.

[0059] In summary, different from the prior art, the present invention provides an LED device 100, which includes a substrate 101, a buffer layer 102, an N-type semiconductor 103, a quantum well active layer 104, an aperture layer 105, a P-type semiconductor 106, a passivation layer 107, and a P-type electrode 109 that are stacked along the growth direction. The aperture layer 105 includes a plurality of insulating portions 1052 and a plurality of conductor portions 1051, and each conductor portion 1051 is located between two adjacent insulating portions 1052. The P-type electrode 109 is disposed on the surface of the passivation layer 107 and is in contact with a part of the P-type semiconductor 106. Among them, a transmissive grating structure 110 is further provided on the light-emitting side of the LED device 100, and the orthographic projection of the transmissive grating structure 110 on the substrate 101 coincides at least partially with the orthographic projection of the conductor portion 1051 on the substrate 101. The transmissive grating structure 110 is used to filter the first light emitted by the quantum well active layer 104 to remove stray light. By providing the transmissive grating structure 110 on the light-emitting side of the LED device 100 and making the orthographic projection of the transmissive grating structure 110 on the substrate 101 coincide at least partially with the orthographic projection of the conductor portion 1051 on the substrate 101, the first light emitted by the quantum well active layer 104 is filtered to remove stray light, thereby enhancing the lighting effect of the LED device 100.

[0060] It should be noted that the above embodiments all belong to the same inventive concept. The descriptions of the embodiments have their own emphases. For the parts not described in detail in individual embodiments, reference can be made to the descriptions in other embodiments.

[0061] The above embodiments only express the implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the inventive concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. An LED device, characterized in that, It includes a substrate, a buffer layer, an N-type semiconductor, a quantum well active layer, an aperture layer, a P-type semiconductor, a passivation layer, and a P-type electrode that are stacked along the growth direction. The aperture layer includes a plurality of insulating portions and a plurality of conductor portions, and each conductor portion is located between two adjacent insulating portions. The P-type electrode is disposed on the surface of the passivation layer and is in contact with a part of the P-type semiconductor; Wherein, a transmissive grating structure is further provided on the light-emitting side of the LED device. The orthographic projection of the transmissive grating structure on the substrate at least partially coincides with the orthographic projection of the conductor portion on the substrate. The transmissive grating structure is used to filter the light emitted by the quantum well active layer to remove stray light.

2. The LED device according to claim 1, wherein, The reflectivity of the N-type semiconductor is greater than that of the P-type semiconductor.

3. The LED device according to claim 2, wherein The transmissive grating structure is located on the surface of the P-type semiconductor away from the substrate, or the transmissive grating structure is located on the surface of the P-type electrode away from the substrate.

4. The LED device according to claim 2, characterized in that, The transmissive grating structure is located on the surface of the conductor portion away from the substrate, and the orthographic projection of the transmissive grating structure on the substrate coincides with the orthographic projection of the conductor portion on the substrate.

5. The LED device according to any one of claims 2 to 4, characterized in that, The LED device further includes a reflective grating structure. The reflective grating structure includes a first patterned layer and a reflective metal layer disposed on the first patterned layer and close to the side of the substrate. The first patterned layer is formed by patterning the surface of the N-type semiconductor close to the substrate.

6. The LED device according to claim 1, wherein The reflectivity of the N-type semiconductor is less than that of the P-type semiconductor.

7. The LED device according to claim 6, characterized in that, The transmissive grating structure is located on the surface of the N-type semiconductor close to the substrate, or the transmissive grating structure is located on the surface of the buffer layer close to the substrate.

8. The LED device according to claim 6, wherein, The transmissive grating structure is located on the surface of the substrate away from the quantum well active layer.

9. The LED device according to any one of claims 6 to 8, characterized in that, The LED device further includes a reflective grating structure. The reflective grating structure is located on the surface of any one of the conductor portion, the P-type semiconductor, and the P-type electrode away from the substrate.

10. The LED device according to claim 9, wherein, The material of the transmissive grating structure is SiO2, and the material of the reflective grating structure is a semiconductor material composed of group III elements and group V elements; the periods of both the transmissive grating structure and the reflective grating structure are 100 - 800 nm, and the depths of both the transmissive grating structure and the reflective grating structure are 50 - 1000 nm.

Images