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

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.

An ultraviolet light-emitting diode (LED) epitaxial structure, comprising: a substrate (1); an undoped buffer layer (2), an N-type AlGaN layer (3), a multi-quantum well structure (4), a superlattice structure (5), an electron blocking layer (6), a P-type AlGaN layer (7), and a P-type GaN layer (8), which are sequentially grown on the substrate (1); the superlattice structure (5) comprises at least one first AlGaN layer and at least one second AlGaN layer, the first AlGaN layer and the second AlGaN layer being alternatingly stacked. Since the superlattice structure (5) is added between the multi-quantum well and the electron blocking layer (6), the superlattice structure (5) may effectively alleviate strain between the last quantum barrier of an active region and the electron blocking layer (6), suppress electron leakage, and increase hole injection rate, thereby improving the optical output power and internal quantum efficiency of an ultraviolet LED, causing the ultraviolet LED to present better light-emitting performance.

The invention discloses a preparation method of an epitaxial structure of a gallium nitride based laser device, comprising the following steps of: (a) epitaxially growing one GaN buffer layer on a substrate; (b) epitaxially growing an n-type light limiting layer on the buffer layer; (c) growing a lower waveguide layer; (d) epitaxially growing an InaGa1-aN / GaN multi-quantum well as an active region; after growing the last InaGa1-aN / GaN multi-quantum well, replacing the last GaN barrier layer by an AlGaN layer, wherein the AlGaN layer is an AlxGa1-xN which is 1-50 nm in thickness and has gradually-changed Al components or is composed of at least two layers of AlyGa1-yN layers with gradually-increased Al components; (e) epitaxially growing one p-type AlzGa1-zN electron blocking layer, wherein in the steps (d) and (e), x is more than or equal to 0 and is less than or equal to y, y is more than or equal to x and is less than or equal to z, and z is more than or equal to y and is less than or equal to 1; (f) growing an upper waveguide layer; (g) growing a p-type light limiting layer; and (h) growing an ohm contact layer. According to the preparation method provided by the invention, the problem of electron accumulation of the uppermost GaN barrier layer and an AlGaN electron blocking layer is solved, and the performance of the laser device is effectively improved.

The invention relates to the field of a semiconductor, and discloses an LED epitaxial structure. The LED epitaxial structure comprises a substrate, a nucleating layer, a non-doped GaN layer, an n type GaN layer and a porous SiN<x> layer on the n type GaN layer, and also comprises an n type GaN hexagonal-pyramid array formed in the holes of the porous SiN<x> layer, and quantum dots on the peak of the hexagonal pyramid, quantum lines on the six ridges and a multi-quantum-well layer on six semi-polar (10-11) crystal surfaces, and a p type GaN filling layer at the tail part; and the GaN hexagonal pyramid and the quantum dots / lines / well layer at different positions thereon form the three-dimensional core-shell structure. The structure is large in light emitting area and high in light extracting efficiency; in addition, due to influences of different In contents and polarization effects and other factors, the light emitting wavelengths of the quantum dots / lines / well structures are also different; through reasonable control, white light emission can be realized; in the preparation method of the GaN hexagonal pyramid array, substrate patterning is not needed, so that the technological process is simple; and meanwhile, the grown GaN crystals are high in quality, so that the luminous efficiency of the LED can be improved effectively.