The invention discloses a light-emitting
diode epitaxial
wafer and a preparation method thereof and belongs to the field of light-emitting
diode manufacturing. An
active layer is arranged to include afirst
barrier layer and a plurality of InGaN well
layers, wherein a plurality of first sub-barrier
layers with a GaN / In<x>Ga<1-x>N / Al<z>Ga<1-z>N / In<y>Ga<1-y>N / GaN
superlattice structure in the firstbarrier layer and the InGaN well
layers are alternately stacked. The GaN / In<x>Ga<1-x>N / Al<z>Ga<1-z>N / In<y>Ga<1-y>N / GaN
superlattice structure is relatively high in energy band and can play a role in preventing electrons from entering a P-type GaN layer, so that an
electron blocking layer does not need to be arranged to prevent the electrons from flowing out of an
active layer. Through the arrangement, the number of holes entering the
active layer can be improved while the electrons are restricted from leaving the active layer, so that the number of the holes which are compounded with the electrons to emit light in the active layer is improved; and furthermore, the polarization condition, caused by the arrangement of the
electron blocking layer, between the
electron blocking layer and the active layer and the P-type layer in an epitaxial layer can also be reduced, so that reduction of a light-emitting
band gap in the epitaxial layer is avoided and the recombination efficiency of the electrons and the holes is improved, thereby improving the light-emitting efficiency of a light-emitting
diode.