Epitaxial growth method for improving LED light emitting efficiency

The invention provides an epitaxial growth method for improving LED light emitting efficiency. The epitaxial structure sequentially includes a substrate, a low-temperature GaN buffer layer, a GaN non-doping layer, an N-type GaN layer, an MQW, an MQW active layer, a low-temperature P-type GaN layer, a P-type AlGaN layer, a high-temperature P-type GaN layer and a P-type contact layer from bottom to top. The last LQB in the MQW active layer in the growth process is of a multi-layer or multi-component composite structure, and the structure of the last LQB in the MQW active layer is in an AlxGal-xN/InyGal-yN(0&1t; x&1t; 1,0&1t; y&1t;1) superlattice growth mode. By means of the LQB layers in an active region of the epitaxial structure, the last LQB layer in the MQW layer is preferably in the AlGaN/InGaN superlattice growth mode, high crystal mass can be achieved, stress caused by lattice mismatch is effectively reduced, electron leakage is effectively reduced, the radiation composite efficiency of electrons and holes is improved, and accordingly the light emitting efficiency is improved.