The invention discloses a light-emitting
diode epitaxial
wafer and a preparation method thereof, and belongs to the technical field of semiconductors. The light-emitting
diode epitaxial
wafer comprises a
sapphire substrate, a low-temperature buffer layer, a high-temperature non-doped GaN layer, a first defect
barrier layer, an N-type GaN layer, a stress release layer, a multi-
quantum well layer, a P-type
electron blocking layer, a P-type GaN layer and a P-type
contact layer, wherein the low-temperature buffer layer, the high-temperature non-doped GaN layer, the first defect
barrier layer, the N-type GaN layer, the stress release layer, the multi-
quantum well layer, the P-type
electron blocking layer, the P-type GaN layer and the P-type
contact layer are sequentially laminated on the
sapphire substrate; a second defect
barrier layer is inserted into the N-type GaN layer; the first defect barrier layer comprises alternately laminated AlGaN
layers and GaN
layers; the second defect barrier layer comprises alternately laminated SiN films and N-type AlGaN
layers; and the stress release layer comprises alternately laminated InGaN layers and GaN layers. According to the light-emitting
diode epitaxial
wafer, extension of defects formed by
lattice mismatch into the multi-
quantum well layer is effectively suppressed; stress release is enhanced; the
crystal quality is improved; leakage passages are reduced; the anti-
static electricity capacity of an LED
chip is improved; and the product yield is improved.