31results about How to "Reduced polarizing electric field" patented technology

The invention provides a nitride light-emitting diode (LED) epitaxial wafer and a growing method thereof and relates to the technical field of semiconductor optoelectronics. The nitride LED epitaxial wafer structurally and sequentially comprises a substrate, a low-temperature buffer layer, an unintentionally doped GaN, an N-shaped electron-injection layer, an InGaN/GaN inserting layer, an active area, an electron blocking layer, a u-GaN/p-GaN superlattice and a p-GaN hole-injection layer from bottom to top. The InGaN/GaN inserting layer is grown between the N-shaped electron-injection layer and the active area so as to effective relieve stress of the active area, lower polarization electric fields, reduce limitation of stark effect through a quantum well, and improve luminance and anti-static properties. The u-GaN/p-GaN superlattice is inserted between the electron blocking layer and the P-shaped hole-injection layer so as to improve current expansion capacity and lower chip operating voltage.

The invention discloses a GaN-based light-emitting diode epitaxial wafer production method and a produced epitaxial wafer, and belongs to the field of semiconductor light-emitting diodes. The method includes growing a buffer layer, an n-type GaN layer, a stress regulation layer, a multiple quantum well layer, a p-type GaN layer and a p-type ohmic contact layer on a substrate sequentially. The stress regulation layer is of a multi-period structure. A growth method of each period of the multi-period structure includes growing a stress regulation InGaN sub layer at a first growth temperature, supplying hydrogen into a reaction chamber at a second growth temperature after the stress regulation InGaN sub layer finishes growing, and etching the surface of the stress regulation InGaN sub layer, wherein the second growth temperature is different from the first growth temperature. The GaN-based light-emitting diode epitaxial wafer production method and the produced epitaxial wafer have the advantages that through treatment of the stress regulation InGaN sub layer, a smooth contact surface is formed between the stress regulation InGaN sub layer and a stress regulation GaN sub layer, and accordingly, continuous extension of defects is prevented.

The invention relates to a process of growing a nucleating layer on the surface of a patterned substrate at a low temperature to form an uneven surface. The invention overcomes the problem that in a conventional LED (Light-Emitting Diode) device structure, an active layer has a superstrong depolarization field, and thus, an energy band of a quantum well is inclined, an electron hole wave function is separated in space and the radiative recombination efficiency is reduced, so that the internal quantum efficiency of a LED is reduced. The invention also provides an epitaxial wafer structure of a gallium nitride-based LED and a preparation method of the epitaxial wafer structure, wherein the epitaxial wafer structure has high crystalline quality and a nonplanar active layer structure is implemented on a weak polarity surface of the epitaxial wafer structure. Therefore, the internal quantum efficiency of the LED is improved.

The invention relates to the field of a semiconductor, and discloses an LED epitaxial structure. The LED epitaxial structure comprises a substrate and porous SiNx layers laminated on the substrate, and further comprises n-type GaN nano rod arrays formed in apertures of the SiNx layers, multi-quantum well layers which are successively laminated and wrap each surface of the GaN nano rod arrays, and a P-type GaN layer. The GaN nano rod arrays, the multi-quantum well layer wrapping each surface of the GaN nano rod arrays, and the P-type GaN layer form a three-dimensional core shell structure, the specific surface area is large, compared to a thin film material, more photons can be generated under the same current density, and the internal quantum efficiency of the LED epitaxial structure is improved. At the same time, a patterned substrate is unnecessary for growth of the GaN nano rod arrays, and the technical cost is low. The preparation method of the three-dimensional LED epitaxial structure is simple, is easy to implement and low in technical cost and can effectively guarantee the product yield.

The invention provides a deep UV LED, which includes a substrate; an undoped buffer layer located on the surface of the substrate; an N type AlGaN layer on the undoped buffer layer and far away from the surface of the substrate; a multi-quantum well structure on the undoped buffer layer and far away from the surface of the substrate; and a P type AlGaN structure on the multi-quantum well structure and far away from the surface of the substrate, wherein the V type Al component of the P type AlGaN structure is gradually changed. The P type AlGaN structure with the gradually changed V type Al component is subjected to polarization doping. The Al component in the P type AlGaN structure with the gradually changed V type Al component is different from the Al component in the multi-quantum well structure. The P type AlGaN structure with the gradually changed V type Al component is far away from a P type GaN layer on the surface of the substrate. Based on the P type AlGaN structure with the gradually changed V type Al component, obtained electron holes are higher in concentration. Therefore, the internal quantum efficiency and the emission power of the UV LED are improved.

The invention discloses an MQW (multiple quantum well)-growth applied GaN (gallium nitride)-based green-light LED (light emitting diode) epitaxial structure, and relates to the technical field of LED epitaxial production, in particular to growth technology of GaN-based green-light LEDs. The MQW-growth applied GaN-based green-light LED epitaxial structure comprises a GaN nucleating layer, a non-mixed GaN layer, a n-type GaN layer, an InGaN (indium gallium nitride)/GaN MQW active layer and a p-type GaN layer which are sequentially grown on a substrate. The InGaN/GaN MQW active layer comprises a GaN barrier layer, an InGaN quantum well layer and a temperature-changing GaN transition layer. A buffering layer shallow well with low In components is grown between the GaN barrier layer and the InGaN quantum well layer of the InGaN/GaN MQW active layer. Stress between a quantum well and a barrier is greatly reduced, and stress difference between the quantum well and the barrier is relieved, so that a polarization electric field in the quantum well is greatly reduced. By the buffering layer shallow well between the barrier and the quantum well, the polarization electric field is reduced, spatial segregation of an electron-hole wave function is relieved, and effective radiative recombination can be improved.

The invention provides a method for preparing an LED (Light-Emitting Diode) with a GaN thick film vertical structure. The method comprises the following steps of: preparing a mask pattern on the polished surface of a substrate, wherein the polished surface of the substrate is divided into a plurality of separated areas by the mask pattern to obtain the patterned substrate; depositing an n-type doped GaN thick film on the patterned substrate, wherein the thickness of the GaN thick film is ought to be more than that of the mask pattern; and epitaxially growing a multi-period quantum well LED on the GaN thick film. According to the invention, by means of partitioned growth of the GaN thick film, stresses induced by lattice mismatch and heat mismatch are released, the problem of substrate cracking in secondary epitaxy is solved, the warping degree of the substrate is reduced, and the subsequent processes of laser based substrate stripping and chip manufacturing are facilitated.

The invention provides an LED epitaxial structure, a manufacturing method thereof and an LED chip. The epitaxial structure comprises a substrate, a first type semiconductor layer, a multi-quantum wellbarrier layer, an electron blocking layer and a second type semiconductor layer which are stacked in sequence. The multi-quantum well barrier layer comprises a quantum well and a quantum barrier, andthe quantum barrier is of an AlInGaN/AlGaN superlattice structure. The AlInGaN/AlGaN superlattice structure has a plurality of periods, each period comprises an AlInGaN layer and an AlGaN layer, andthe Al component of the AlInGaN layer is changed along with the increase of the number of periods so as to be matched with the polarization of the quantum well. The quantum barrier adopts an AlInGaN/AlGaN superlattice structure, so that the stress mismatch between the quantum well and the quantum barrier can be reduced, the polarization electric field can be reduced, and the electron leakage caused by the bending of the energy band of the quantum well can be reduced. Meanwhile, polarization matching with the quantum well is realized by adjusting the Al component.

The invention provides an epitaxial wafer of a light emitting diode and a preparation method of epitaxial wafer, and belongs to the technical field of photoelectron manufacturing. The epitaxial wafercomprises a substrate, an AlN buffer layer, a three-dimensional nucleating layer, a u-type GaN layer, an n-type GaN layer, a multi-quantum well layer, a low-temperature p-type layer, an electron blocking layer and a high-temperature p-type layer, the multi-quantum well layer comprises a plurality of InxGa1-xN quantum well layers, a plurality of GaN quantum barrier layers and a composite structurelocated between the InxGa1-xN quantum well layers, and the composite structure comprises a n-InyGa1-yN layer and a SiN layer. Si atoms in the n-In-yGa1-yN layer can fill defect vacancies in the InGaNmaterial, the InGaN material with a low In component is beneficial to weakening a polarization electric field and improving energy band inclination, and the SiN layer is beneficial to uniform diffusion of carriers in the multi-quantum well layer, improving the carrier localization effect and improving the luminous efficiency of the LED.

The invention relates to the technical field of a semiconductor photoelectronic device, in particular to a novel AlGaN-based ultraviolet light emitting diode. The novel AlGaN-based ultraviolet light-emitting diode comprises a tube body, wherein a sapphire substrate, a AlN nucleating layer, a non-doped u-type Al<x1>In<y1>Ga<1-x1-y1>N buffer layer, an n-type Al<x2>In<y2>Ga<1-x2-y2>N layer, a Al<x3>In<y3>Ga<1-x3-y3>N/Al<x4>In<y4>Ga<1-x4-y4>N quantum well active region, a p-type NiO/Al<x5>In<y5>Ga<1-x5-y5>N superlattice structure electron blocking layer, a p-type Zn<z1>Mg<z2>Ni<1-z1-z2>O layer and an indium tin oxide transparent conductive layer are sequentially arranged in the tube body from bottom to top, a p-type ohmic electrode is led out of the indium tin oxide transparent conductive layer, and an n-type ohmic electrode is led out of the n-type Al<x2>In<y2>Ga<1-x2-y2>N layer. In the novel AlGaN-based ultraviolet light emitting diode, the forbidden bandwidth and the lattice constant can be independently adjusted by the AlInGaN material, the crystal quality of an epitaxial layer is effectively improved, the p-type NiO/Al<x5>In<y5>Ga<1-x5-y5>N superlattice structure has a high quantum limitation effect on a carrier, the p-type Zn<y2>Mg<y2>Ni<1-y2-y2>O is used for improving the combination efficiency of the carrier in the active region, the sapphire substrate material on a r surface, an m surface or an a surface is a non-polarity or semi-polarity AlGaN material, the separation of electron and hole wave functions in a space is reduced, and the radiation combination efficiency of the carrier is improved.

The invention discloses a nitride quantum well infrared photodetector containing a polarized regulation layer and a preparing method of the nitride quantum well infrared photodetector. The nitride quantum well infrared photodetector structurally comprises a lower electrode contact layer, a function layer and an upper electrode contact layer, the function layer is constituted by a periodic heterojunction structure of AlxGa1-xN/AlyGa1-yN/ AlzGa1-zN, wherein 0<=x<z<y<=1. According to the nitride quantum well infrared photodetector containing the polarized regulation layer and the preparing method of the nitride quantum well infrared photodetector, the polarized regulation layer is introduced between a quantum potential well layer and a quantum potential barrier layer, a polarized electric field of the potential barrier layer is effectively shielded, the migration efficiency of light induced electrons on the quasi-continuous state energy level can be improved, further the response signal strength of a device is improved, and the problem that currently an AlGaN-based quantum well infrared photodetector at a middle (far) infrared band can only work at an ultralow temperature is expected to be solved.

The invention discloses a GaN-based semiconductor device with a composite gradual-change quantum barrier structure and a preparation method of the semiconductor device. The device comprises a multi-quantum well structure, the multi-quantum well structure comprises InGaN layers which grown alternatively, the average In content in the different quantum barrier layers in the multi-quantum well structure is reduced gradually from the P type side to the N type side, and the In content in at least one quantum barrier layer is increased gradually from the P type side to the N type side. Due to use of the composite gradual-change quantum barrier structure in the device, the polarized electric field in the quantum well region can be reduced, the electron-hole composite efficiency is increased, hole transportation is improved, distribution non-uniformity of the holes among wells is reduced, leakage of electrons is reduced, the light emitting efficiency of LED devices and the like can be improved obviously, the problem of decrease of the light emitting efficiency is inhibited substantially, preparation technology is simple and controllable, and convenience is provided for large-scale enforcement.

The invention provides an optimization method for a large-power green-light LED epitaxial structure of a Si substrate, and the method comprises the following steps: performing the Si substrate processing, depositing an AlN buffer layer on the Si substrate, and then sequentially growing an N-GaN layer, a low-temperature GaN layer, a 10-cycle InGaN/GaN superlattice layer, an electron injection layer, a 6-cycle InGaN/GaN blue MQW layer, a 7-cycle InGaN/GaN green-light MQW layer, a P-AlGaN electron blocking layer and a P-GaN layer, and continuing to grow a highly-Mg-doped P-GaN layer; then performing cooling to 710-730 DEG C, performing annealing for 30 to 60 minutes, and then performing the furnace cooling to obtain the large-power green-light LED epitaxial structure of the Si substrate in anoptimized design. The method can optimize the N-type layer doping, the thickness of the low-temperature GaN layer in the intercalation layer, the InGaN/GaN superlattice layer In component and the blue multi-quantum well structure well thickness, so that the electrons can be cooled at a large current working density, thereby reducing carrier leakage, reducing a polarization electric field in a quantum well, effectively alleviating the quantum efficiency degradation and improving the luminous efficiency of a device.

The invention discloses a GaN-based LED epitaxial structure of an inverted triangular barrier, and a growth method thereof. A light-emitting layer is formed by barrier layers and quantum well layers alternately, wherein each barrier layer is a GaN-InxGa1-xN-GaN barrier layer, called a GIG barrier layer for short, and is sequentially formed by one GaN barrier, an InxGa1-xN barrier and one GaN barrier according to the growth sequence, and x in the AlxGa1-xN barrier gradually grows from 0 to 0.15 and then to 0 along the growth direction. The GaN barrier structure of a traditional LED is replacedwith a GIG inverted-triangle-shaped barrier structure, a polarization electric field of a barrier and a quantum well can be effectively reduced through application of an InGaN material in the barrierlayer, the quantum stark effect is effectively inhibited, meanwhile, the effective height of the barrier is not reduced through the special barrier shape provided by the invention, and the inverted triangular potential barrier can still effectively limit current carriers.