699 results about "Electron blocking layer" patented technology

An organic light-emitting device comprises an anode, a cathode and an organic layer formed between the anode and the cathode, and the organic layer comprises a hole injection layer, a hole transmission area, an electron blocking layer, a light-emitting area and an electron transmission area. The hole transport region comprises a first material and a second material, the first material and the second material are sequentially evaporated to form two hole transport layers, and the first material is selected from a compound shown in the formula 1; and the second material is selected from a compound shown in a formula 2. According to the invention, the first material with a high refractive index is used as the first hole transport layer, the second material with a low refractive index is used as the second hole transport layer, and the structures of the first material and the second material are respectively limited at the same time. The invention overcomes the limitation of a single material or a simple mixed material in the aspects of hole transport and luminous efficiency. .

A GaN-based blue-green LED epitaxial structure, relating to the field of semiconductor photoelectric devices. The GaN-based blue-green LED epitaxial structure comprises a substrate, and a buffer layer, a dislocation regulation layer, a U-GaN layer, an N-GaN layer, a multi-quantum-well layer, an electron blocking layer and a P-GaN layer which are sequentially stacked on the substrate, wherein the dislocation regulation layer is of a periodic structure with the number of periods ranging from 2 to 10, and each period comprises a GaN layer and an Si-doped GaN layer that are sequentially stacked. The crystal quality of the epitaxial structure can be improved, thereby improving the light-emitting efficiency and the antistatic performance of the blue-green LED based on the epitaxial structure.

The invention relates to the technical field of semiconductor devices, in particular to a low-working-current-density green light Micro-LED epitaxial structure and a preparation method thereof. The epitaxial structure comprises a substrate, a buffer layer, an N-type semiconductor layer, a low-temperature stress release layer, a multi-quantum well light-emitting layer and a P-type semiconductor layer. The electron blocking layer is not arranged on the multi-quantum-well light-emitting layer, the multi-quantum-well light-emitting layer comprises four sub-layers including a first light blue light multi-quantum-well layer, a second blue light multi-quantum-well layer, a third green light multi-quantum-well layer and a fourth light blue light multi-quantum-well layer, and the In component content in the third green light multi-quantum-well layer is larger than that in other layers. The third cyan light multi-quantum well layer is a main light-emitting unit and is not provided with an electron blocking layer, so that the blocking effect on hole injection can be eliminated, the hole injection efficiency of the P-type semiconductor layer is remarkably improved, and the matching degree of electron hole concentration in a multi-quantum well light-emitting layer region is improved.

The invention relates to the technical field of semiconductor devices, in particular to a multiband light-emitting diode epitaxial structure and a preparation method thereof. The multiband light-emitting diode epitaxial structure sequentially comprises a substrate, a buffer layer, an N-type semiconductor layer, a low-temperature stress release layer, a multi-quantum well light-emitting layer, an electron blocking layer and a P-type semiconductor layer from bottom to top, the multi-quantum well light-emitting layer comprises four sub-layers, namely a first long-wave cyan light multi-quantum well layer, a second short-wave cyan light multi-quantum well layer, a third long-wave blue light multi-quantum well layer and a fourth short-wave blue light multi-quantum well layer which are sequentially stacked and grown from bottom to top, and the light-emitting wavelengths are sequentially decreased. Meanwhile, by combining the design of the sub-layers of the multiple quantum well light-emitting layers and through the synergistic effect of exciting light of all wave bands, the overall excitation efficiency can be improved, full-spectrum white light is output, the full-spectrum white light is closer to sunlight, the light-emitting efficiency is high, the color rendering property is good, the stability is better, and harm to human eyes is small.

To improve the luminous efficiency of a UV light-emitting device, the UV light-emitting devices disclosed herein have an AlGaN-based crystal or an InAlGaN-based crystal, and comprise an emission layer, at least one electron blocking layer, a first p-type doped layer, and a composition gradient layer in which the Al composition ratio varies depending on the position over a thickness direction of the layer stack, stacked in this order in the direction of the flow of electrons. The Al composition ratio varies depending on the position over the thickness direction in the composition gradient layer. The UV light-emitting devices are implemented as UV-region light-emitting diodes and laser diodes.

The invention relates to the technical field of chip preparation, and provides a chip based on an annular photonic crystal and a preparation method thereof. The preparation method comprises the following steps: growing a nucleating layer on a substrate; growing a superlattice structure on one side, away from the substrate, of the nucleating layer; sequentially growing an n-type coating layer, an n-type waveguide layer, a quantum well and a p-type electron blocking layer on one side, deviating from the nucleating layer, of the superlattice structure; etching a plurality of annular cavities on the p-type electron barrier layer to form an annular photonic crystal; growing a p-type extension contact layer on one side, deviating from the quantum well, of the p-type electron blocking layer; and carrying out in-situ annealing treatment. According to the preparation method, the directivity of the photonic band gap can be effectively adjusted, uniform light waves in all directions on the side face can be formed, so that leakage of laser from a non-light-emitting area on the side face is restrained, the light emitting efficiency is improved, the annular photonic crystals are periodically distributed, and the light beam quality is effectively guaranteed.

The invention discloses a light-emitting diode epitaxial wafer and a preparation method thereof, and relates to the technical field of semiconductors. The light-emitting diode epitaxial wafer comprises a substrate, and a buffer layer, a non-doped GaN layer, an N-type GaN layer, an electron dredging layer, a multi-quantum well layer, an electron blocking layer and a P-type GaN layer which are stacked on the substrate in sequence, the electron dredging layer comprises a first sub-layer, a second sub-layer, a third sub-layer and a fourth sub-layer which are sequentially stacked, the first sub-layer is a Si3N4 layer, the second sub-layer comprises an AlGaN layer, a first InGaN layer and a first GaN layer which are periodically and alternately stacked, the third sub-layer comprises a second GaN layer and a second InGaN layer which are periodically and alternately stacked, and the fourth sub-layer is a Si3N4 layer. And the fourth sub-layer comprises an AlInGaN layer, a third InGaN layer and a third GaN layer which are periodically and alternately stacked. According to the invention, while the electronic expansibility is improved, excessive electrons are prevented from entering the multi-quantum well layer to generate electron overflow.

The invention discloses a deep ultraviolet LED epitaxial structure, a deep ultraviolet LED device comprising the same and a preparation method, and the epitaxial structure sequentially comprises a sapphire substrate, an AlN nanowire array layer, an AlN intrinsic layer and an AlGaN light-emitting structure layer from bottom to top. The AlGaN light-emitting structure layer further comprises an n-type AlGaN electron injection layer, a quantum well active layer, a p-type AlGaN electron blocking layer and other device structures. According to the invention, the vertically arranged AlN nanowire array is introduced to replace a traditional AlN buffer layer, so that lattice mismatching stress caused by a substrate is significantly released, and the dislocation density of an epitaxial layer is effectively reduced; meanwhile, the introduction of the AlN intrinsic layer further flattens the epitaxial interface and optimizes the lattice quality, thereby providing a high-quality template for the growth of a high-performance AlGaN material. The epitaxial structure is suitable for an LED device in a deep ultraviolet band, and the crystal quality, the electrical property and the luminous efficiency of the device can be improved.

The invention relates to a P-type GaN LED epitaxial structure based on segmented annealing and compensation doping and a preparation method thereof, and belongs to the technical field of nitride semiconductor epitaxial growth and doping activation. The epitaxial structure sequentially comprises a buffer layer, a non-doped GaN layer, an N-type GaN layer, a multi-quantum well active layer, a P-type AlGaN electron barrier layer, a P-type GaN layer and an MgN compensation layer which are arranged on the substrate layer; wherein the MgN compensation layer is a high-concentration magnesium-doped nitride semiconductor layer, is arranged on the P-type GaN layer, and is used for compensating Mg loss and inhibiting nitrogen vacancy formation in the subsequent annealing process. The preparation method comprises the steps of performing multi-stage annealing treatment on the P-type GaN layer, performing epitaxial growth and annealing on the compensation layer, and finally performing low-temperature post-treatment annealing to form a surface passivation region. According to the structure, the Mg activation efficiency and the hole concentration are remarkably improved through an in-vivo activation and surface compensation synergistic mechanism, the contact resistance is reduced, the conductivity and the light-emitting performance of an LED device are improved, and the structure has excellent implementability and industrialization prospects.

The invention discloses a thermal-decay-resistant red light Micro LED epitaxial structure and a preparation method thereof. The epitaxial structure sequentially comprises a substrate layer, an n-type buffer layer, an n-type etching barrier layer, an n-type ohmic contact layer, an n-type limiting layer, a quantum well structure, a p-type spacer layer, a p-type electron barrier layer and a p-type ohmic contact layer from bottom to top. Wherein the quantum well structure is formed by alternating 1-5 pairs of InGaP well layers and three-section type p-type AlGaInP barrier layers, and the three sections of barrier layers adopt gradient energy level design and are all subjected to p-type doping; according to the invention, the problems of carrier loss and low recombination efficiency at high temperature in the prior art are solved by blocking electron overflow through the gradient energy level barrier and supplementing the hole concentration through p-type doping, so that the 85 DEG C external quantum efficiency attenuation rate is less than or equal to 10%, the service life is prolonged to more than 50,000 hours, and the process is compatible with mass production and is suitable for the fields of display, illumination and the like.

The invention relates to the technical field of semiconductor photoelectrons, and discloses a vertical-cavity surface-emitting laser with an inverted structure and a preparation method of the vertical-cavity surface-emitting laser. The vertical cavity surface emitting laser with the inverted structure comprises a heterogeneous substrate, wherein a heat dissipation functional layer, a metal adhesion layer and a metal bonding layer are arranged on the surface of the heterogeneous substrate from bottom to top; the epitaxial structure comprises a p-type electrode, an ITO current expansion layer, a SiO2 current limiting layer, a first dielectric DBR layer, a p-type GaN layer, an electron blocking layer, a quantum well active region, an n-type GaN layer, a second dielectric DBR layer and an n-type electrode from bottom to top; and the p-type electrode is positioned at the bottom of the epitaxial structure and is bonded with the metal bonding layer to form an inverted structure. According to the vertical cavity surface emitting laser with the inverted structure provided by the invention, the heat dissipation function layer and the inverted structure design effectively improve the heat dissipation capability and the current uniformity of the device, and the service life, the performance stability and the reliability of the device are remarkably improved.

The invention provides a GaN-based LED epitaxial wafer and a preparation method thereof, and the method comprises the following steps: S1, providing a substrate, and placing the substrate on a graphite disc of an MOCVD reaction chamber; s2, carrying out heat treatment on the substrate; s3, growing a buffer layer on the substrate after heat treatment; s4, sequentially growing an unintentional doping layer and an N-type GaN layer on the buffer layer; s5, growing a multi-quantum well light-emitting layer on the N-type GaN layer; s6, growing a P-type electron blocking layer on the multi-quantum well light-emitting layer; step S7, growing a P-type GaN layer on the P-type electron barrier layer; and S8, after growing the P-type GaN layer, adjusting the temperature of the reaction chamber to 20-30 DEG C to obtain the GaN-based LED epitaxial wafer. The GaN-based LED epitaxial wafer obtained by the method has fewer surface particles and higher surface quality.

The invention relates to the technical field of semiconductor light-emitting devices, and particularly discloses an epitaxial structure for improving the internal quantum efficiency of a green Micro LED. The epitaxial structure comprises a substrate, and a buffer layer, an undoped GaN layer, an n-type GaN layer, a stress release layer, an active layer, a low-temperature Mg heavily-doped GaN layer, an electron barrier layer, a p-type GaN layer and a p-type GaN contact layer which are sequentially arranged on the substrate. The active layer comprises a plurality of periods of InGaN quantum well layers and an InAlGaN / GaN superlattice quantum barrier layer alternating structure, and a CAP layer formed by an AlGaN / GaN superlattice is arranged behind each quantum well layer. By adopting a wide-well narrow-barrier structure, a superlattice CAP layer for neutralizing a polarization electric field and a quaternary InAlGaN barrier structure for lattice matching and hole injection enhancement, multiple regulation and control of a polarization field, dislocation density and hole transport are realized, the internal quantum efficiency of a green-light Micro LED is remarkably improved, and the green-light Micro LED epitaxial structure is suitable for epitaxial preparation of a high-performance Micro LED chip.

The invention discloses a graphene integrated electrode LED epitaxial structure and a chip preparation method. The epitaxial structure sequentially comprises a GaAs substrate, an n-type GaAs buffer layer, an n-type limiting layer, a non-doped quantum well structure, a p-type spacer layer, a p-type electron barrier layer and a p-type GaP ohmic contact layer from bottom to top. The preparation method comprises the steps of epitaxial structure growth, p-type ITO transparent conductive layer preparation, bonding and substrate removal, mesa structure preparation, passivation isolation, graphene interconnection layer preparation and n-type electrode preparation. Graphene is used for replacing a traditional n-type GaAs ohmic contact layer and an ITO electrode, the problems of poor red light absorption, poor heat dissipation and mechanical brittleness of a traditional structure are solved, the red light transmittance of the chip is improved, the junction temperature under 3 currents is greatly reduced, the chip can bear tensile strain larger than 20%, the chip is suitable for flexible scenes, and the chip is suitable for high-performance large-scale production of red light Micro LEDs.

The present invention provides a light-emitting diode epitaxial wafer and a method for fabricating the same. The light-emitting diode epitaxial wafer comprises a substrate, and a buffer layer, a three-dimensional nucleation layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a P-type GaN layer sequentially deposited on the substrate. The three-dimensional nucleation layer comprises a stacked first and second three-dimensional nucleation sublayers, the thickness of the first three-dimensional nucleation sublayer being less than that of the second three-dimensional nucleation sublayer, both being MgGaN layers, and the growth temperature of the second three-dimensional nucleation sublayer being 10 to 100°C higher than that of the first three-dimensional nucleation sublayer. This light-emitting diode epitaxial wafer can increase the density of V-pits, improve carrier injection efficiency, and enhance the optoelectronic performance of the light-emitting diode.

The present invention relates to the field of optoelectronics, and discloses a light-emitting diode epitaxial wafer, a method for manufacturing the same, and an LED. The light-emitting diode epitaxial wafer comprises a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided; the electron blocking layer comprises a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer stacked in sequence. The light-emitting diode epitaxial wafer provided by the present invention reduces electron overflow, improves hole injection efficiency, replenishes hole concentration, and enhances the luminous efficiency of the light-emitting diode.

This invention relates to an aromatic amine organic compound and an organic electroluminescent device containing the same, belonging to the field of semiconductor materials technology. The structure of the compound provided by this invention is shown in general formula (1): When the hole transport material or electron blocking layer material of the organic electroluminescent device is prepared by using the aromatic amine compound of this invention, the device voltage can be reduced and the device life can be extended at the same time, especially the device high temperature life is significantly improved.

The invention provides a carbazole compound, an intermediate and an organic electroluminescent device. The carbazole compound has a structure as shown in a formula I. Through the design of the carbazole compound, the carbazole compound with excellent performance is prepared, and the organic electroluminescent device prepared by taking the carbazole compound as a material of the electron blocking layer has relatively low driving voltage, relatively high current efficiency and relatively long service life.

The invention is suitable for the technical field of semiconductors, and provides a blue-green double-peak LED epitaxial growth method, which comprises the following steps: processing a substrate, growing a low-temperature GaN buffer layer, growing a non-doped GaN layer, growing a Si-doped N-type GaN layer, growing a multi-quantum well layer, growing an AlGaN electron barrier layer, growing a Mg-doped P-type GaN layer, and cooling. Wherein the growth of the multi-quantum well layer sequentially comprises the steps of growing a first MQWs, growing a tunnel junction layer, growing a second MQWs and growing an AlGaN / GaN superlattice layer, the tunnel junction layer is introduced into the multi-quantum well layer to enhance tunneling of holes, meanwhile, the AlGaN / GaN superlattice layer is introduced, gradual change of an Al component in AlGaN is controlled by controlling the introduction time of TMAl, the problem of light emitting peak broadening is solved, and the light emitting efficiency is improved. The quantum well is ensured to emit blue light and green light at the same time, the color saturation of the light is improved, and the color temperature is reduced.

According to one embodiment, a display device includes an anode, an organic EL element layer including a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer, and a cathode, wherein ΔE2_LUMO is defined as a potential barrier between the electron transport layer and the hole blocking layer, and the light-emitting layer, ΔE2_HOMO is defined as a potential barrier between the hole transport layer and the electron blocking layer, and the light-emitting layer, and each of ΔE2_LUMO and ΔE2_HOMO is 0.1 eV or higher and 0.5 eV or less.

The invention relates to the technical field of light emitting diodes, and discloses a multiband LED epitaxial structure and a preparation method thereof, the epitaxial structure comprises a substrate, a buffer layer, an N-type semiconductor layer, a low temperature stress release layer, a multi-quantum well light emitting layer, an electron blocking layer and a P-type semiconductor layer, the multi-quantum well light-emitting layer comprises a first multi-quantum well layer, a second multi-quantum well layer, a third multi-quantum well layer and a fourth multi-quantum well layer which are sequentially stacked, and each multi-quantum well layer comprises an InGaN quantum well layer and a variable barrier height regulation barrier layer which are periodically and alternately stacked. The variable barrier height regulation barrier layer comprises five sub-layers which are sequentially stacked on the InGaN quantum well layer, lambda 1 > lambda 2 > lambda 3, and lambda 3 = lambda 4. The healthy full-spectrum white light LED light source with the high color rendering index can be generated, the short-wave blue light is small in proportion, damage to human eye omentum cells is small, and the light emitting efficiency is high.

The present disclosure relates to semiconductor manufacturing technology, particularly relates to a light-emitting diode, which includes a light-emitting layer, an N-type semiconductor layer, a P-type semiconductor layer, an electron blocking layer and a connecting layer. The light- emitting layer has a first side and a second side opposite to each other. The N-type semiconductor layer is disposed on the first side of the light-emitting layer. The P-type semiconductor layer is disposed on the second side of the light-emitting layer. The electron blocking layer is disposed between the light-emitting layer and the P-type semiconductor layer. The connecting layer is disposed between the light-emitting layer and the electron blocking layer, wherein, the connecting layer is doped with indium.

The invention discloses a sapphire gallium nitride-based red light epitaxial wafer structure and a preparation method thereof, and belongs to the technical field of semiconductors, and the sapphire gallium nitride-based red light epitaxial wafer structure comprises a patterned sapphire substrate, a GaN substrate, n-type AlGaN, an InGaN quantum well, an AlGaN electron barrier layer, p-type GaN, ITO and a first electrode which are sequentially laminated; a second electrode is arranged on the n-type AlGaN; the InGaN quantum well, the AlGaN electron barrier layer, the p-type GaN and the ITO form a red light enhancement structure; a plurality of circular through holes determined based on a light scattering theory and a quantum confinement stark effect are formed in the vertical direction of the red light enhancement structure between the first electrode and the second electrode in a penetrating manner; under the condition that voltage is applied to the first electrode and the second electrode, generated electrons and holes are compounded in the InGaN quantum well to generate red light, and the quality of the red light epitaxial wafer is effectively improved.

The invention provides a nitride semiconductor laser. The laser comprises a substrate, a lower coating layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper coating layer which are sequentially arranged from bottom to top. And the lower waveguide layer comprises any one or a combination of more of InGaN, GaN, InN, AlInGaN, an InGaN / GaN superlattice, an InGaN / AlGaN superlattice, an InGaN / AlGaN superlattice, an InGaN / AlInN superlattice and an InGaN / AlInGaN superlattice. The peak rate electric field distribution of the lower waveguide layer has an arc distribution, and the peak rate electric field distribution has a curve distribution of a function y = logax (a > 1). The drift rate distribution of the saturated electrons of the lower waveguide layer has an arc-shaped distribution, and the drift rate distribution of the saturated electrons has a curve distribution of a third quadrant of a function y = x-b (b > 1, b is an odd number). The density distribution of valence band effective states of the lower waveguide layer has a curve distribution of a third quadrant of a function y = (cx + 1) / (cx-1) (c > 1).

An organic semiconductor device with low driving voltage is provided. The light-emitting device includes an anode, a cathode, and an EL layer between the anode and the cathode. The EL layer includes a hole-transport layer and alight-emitting layer. The hole-transport layer is positioned between the anode and the light-emitting layer. The hole-transport layer is not in contact with the anode. The hole-transport layer includes a transport layer material for a light-emitting device and the GSP_slope that is a potential gradient of a surface potential of an evaporated film of the material is higher than or equal to 20 (mV / nm).

There is provided a photoelectric conversion element, an imaging device, and an electronic apparatus that make it possible to improve a response speed. A first photoelectric conversion element (10) according to an embodiment of the present disclosure includes: a first electrode (11); a second electrode (16) disposed to be opposed to the first electrode (11); an organic layer (13) provided between the first electrode (11) and the second electrode (16) and including a hole-transporting material; a work function adjustment layer (15) provided between the second electrode (16) and the organic layer (13) and having an electron affinity or a work function larger than a work function of the first electrode (11); and an electron block layer (14) provided between the organic layer (13) and the work function adjustment layer (15) and having an anisotropic electric susceptibility of 413 or more or an intramolecular dipole moment of 1.84 debye or more.

The invention relates to a blue-green dual-band light-emitting diode epitaxial wafer which comprises a substrate, a buffer layer, an N-type semiconductor layer, a low-temperature stress release layer, a multi-quantum well light-emitting layer, an electron blocking layer and a P-type semiconductor layer which are sequentially stacked in the epitaxial direction. The multi-quantum light-emitting layer comprises a first blue light InGaN layer, a first blue light barrier layer, a first green light barrier layer, a first green light InGaN layer, a second green light barrier layer, a second blue light InGaN layer and a second blue light barrier layer which are sequentially, periodically and alternately grown in the epitaxial direction. The first green light barrier layer comprises a pre-well low-energy-level barrier layer, a pre-well high-energy-level barrier layer and a pre-well polarization compensation barrier layer which are sequentially grown along the epitaxial direction; the second green light barrier layer comprises a post-well polarization compensation barrier layer, a post-well high-energy-level barrier layer and a post-well low-energy-level barrier layer which are sequentially grown along the epitaxial direction; the preparation cost of the backlight source can be effectively reduced, the use of fluorescent powder is reduced, the luminous efficiency is high, and the color rendering performance is good.

The invention discloses a light-emitting diode chip for improving the polarization effect of a quantum well light-emitting layer and a preparation method of the light-emitting diode chip. Comprising a sapphire patterned substrate, a buffer layer, a defect barrier layer, an N-type gallium nitride layer, a current expansion layer, a stress release layer, a quantum well light-emitting layer, a polarization buffer layer, a P-type electron barrier layer, a P-type gallium nitride layer, a transparent conductive layer, an electrode layer and a protective layer which are sequentially arranged from bottom to top. The polarization buffer layer is arranged between the quantum well light-emitting layer and the P-type electron blocking layer, buffers energy level abrupt change, and improves the polarization effect. A composite structure of an In < x > Ga < 1-x > N / GaN superlattice and a GaN / Al < y > Ga < 1-y > N superlattice is inserted between the multi-quantum well layer and the electron blocking layer, mutation of energy level is buffered by adjusting gradient doping of In and Al, the polarization effect in quantum wells caused by high potential barriers of the electron blocking layer is effectively improved, and the luminous efficiency of the diode is further improved.

The invention provides a vertical deep ultraviolet LED epitaxial structure and a preparation method thereof. The vertical deep ultraviolet LED epitaxial structure comprises a substrate, an intrinsic layer, a sacrificial layer, a first electron injection layer, an etching barrier layer, a second electron injection layer, a quantum well active layer, an electron barrier layer and a hole injection layer which are sequentially stacked from bottom to top. Wherein the etching barrier layer is made of an n-type doped AlGaN material or an n-type doped AlN material; the mass percentage content of an Al component of the etching barrier layer is 70%-100%; according to the invention, the etching barrier layer with a high Al component is inserted into the electron injection structure, and the high Al-N bond energy and strong chemical stability of the etching barrier layer are utilized, so that the subsequent epitaxial layer can be effectively prevented from being excessively corroded in the dry etching process of the sacrificial layer, and the interface damage is reduced; meanwhile, the etching barrier layer with the high Al component and the electron injection layer form a remarkable barrier difference, the high barrier can guide electrons to be transversely and uniformly diffused in the electron injection layer, and the current density uniformity of the quantum well active layer is improved.

The invention discloses a GaN-based blue-green light LED epitaxial structure and a preparation method thereof, and a GaN-based blue-green light LED. The GaN-based blue-green light LED epitaxial structure comprises a substrate, and a buffer layer, a 3D layer, a U-GaN layer, an N-GaN layer, a multi-quantum well layer, an electron blocking layer and a P-GaN layer which are stacked on the substrate in sequence; wherein the multi-quantum well layer comprises a shallow well transition layer, a first quantum well layer, a second quantum well layer, a stress release layer and a third quantum well layer which are stacked in sequence; the growth temperature of the first quantum well layer is greater than the growth temperature of the second quantum well layer and greater than the growth temperature of the third quantum well layer, and the number of cycles of alternate stacking of the second quantum well layer is greater than the number of cycles of alternate stacking of the third quantum well layer; the stress release layer is an AlGaN layer or an AlN layer and a GaN layer, wherein the AlN layer and the GaN layer are periodically and alternately stacked. According to the invention, the turn-on voltage of the GaN-based blue-green light LED can be effectively improved.