42results about How to "Increases chance of radiative recombination" patented technology

The invention discloses a high-brightness light emitting diode with a GaN-based multiquantum-well structure and a preparation method thereof, and relates to a light emitting diode. The light emitting diode comprises a substrate, a low temperature buffer layer, an n-type doped GaN layer, 3 to 5 InGaN / GaN multiquantum wells, a p-type doped AlGaN layer, a p-type doped CaN layer, 5 periodic p-InGaN / p-AlGaN superlattice layers, a p-type ohmic contact layer and an n-type ohmic contact layer prepared on the n-type doped GaN layer in turn from bottom to top. The preparation method comprises the following steps: putting the substrate into a reaction chamber to perform thermal treatment for growing a GaN buffer layer, an n-type silicon-doped GaN layer, 3 to 5 periodic InGaN / GaN multiquantum wells with graded components, a p-type Mg-doped AlGaN layer, a p-type Mg-doped GaN layer and 5 periodic Mg-doped p-InGaN / p-AlGaN superlattice layers in turn; performing annealing after epitaxial growth; etching an n-type GaN layer; and preparing the n-type and the p-type ohmic contact layers.

The invention discloses a light-emitting diode epitaxial wafer and a manufacturing method thereof, belonging to the technical field of semiconductors. The epitaxial wafer includes a sapphire substrate, and an undoped GaN layer, an N-type GaN layer, an active layer, and a P-type GaN layer sequentially stacked on the sapphire substrate, and the active layer is an alternately grown InGaN layer and a GaN layer , the epitaxial wafer also includes a superlattice GaN layer, the superlattice GaN layer is laminated between the undoped GaN layer and the N-type GaN layer, and the superlattice GaN layer includes alternately grown first GaN layers and second GaN layers, The first GaN layer is grown in a three-dimensional 3D mode, and the second GaN layer is grown in a two-dimensional 2D mode. By inserting a GaN layer grown in a 3D mode, the present invention can deflect and merge dislocations on the one hand, and on the other hand, effectively change the direction of light reflected back by total reflection, so as to re-emit, thereby improving the luminous efficiency of the LED.

The invention relates to an epitaxial growth method for improving the inner quantum efficiency of a GaN-based LED, belonging to the technical field of semiconductors. The method comprises the following steps of: alternately inputting ammonia gas as well as Group III metal organic source materials of gallium and indium in a growth reaction chamber in a pulsing way during the growth of an In-Ga-N quantum well layer of a GaN-based blue / green light LED active area; and forming a In-Ga-N quantum well luminous layer with high luminous efficiency in a modulation growth process under a set duration, a set interval and a set pulse period. The method can weaken an internally-built electric field of the In-Ga-N / GaN quantum well, improve the quantum localization effect, enhance the radiative recombination rate and increase the inner quantum efficiency of luminescence so as to improve the luminous efficiency and the brightness of the LED. The method is suitable for the MOCVD (Metallo Organic Chemical Vapor Deposition) epitaxial growth of a nitride-based blue / green light LED epitaxial material with high brightness and high luminous efficiency.

The invention discloses an ultraviolet LED epitaxial structure and a preparation method thereof, belonging to the technical field of epitaxial growth of nitride semiconductor light-emitting devices, comprising: a substrate, a buffer layer, an N-type aluminum gallium nitrogen layer, a multi-quantum well light-emitting layer, and an electron barrier Layer, P-type aluminum gallium nitride layer and P-type gallium nitride layer; each quantum barrier layer in the multi-quantum well light-emitting layer includes multiple sub-layers, and the thickness of the sub-layers and the content of aluminum molecules grow according to the bottom-up growth The direction increases first and then decreases, and the increasing and decreasing boundary layer is the middle sublayer of each quantum barrier layer. The invention improves the internal quantum efficiency and light output power of the AlGaN-based ultraviolet LED.