Abstract: An AlGaN template including a substrate and an Al1-xGaxN crystallization thin film deposited on the substrate, where 0<x<1. A method for preparing the AlGaN template includes providing a substrate; and depositing an Al1-xGaxN crystallization thin film on the substrate.

Abstract: A light-emitting diode epitaxial wafer, including: a substrate; and a buffer layer, an undoped GaN layer, an n-type GaN contact layer, a multi-quantum well layer, and a p-type GaN contact layer, which are sequentially laminated on the substrate in that order. The multi-quantum well layer includes GaN barrier layers and at least one InxGa1-xN well layer, where 0<X<1. At least part of the GaN barrier layers and the at least one InxGa1-xN well layer include a pre-grown layer provided therebetween; the pre-grown layer is made of InN, or the pre-grown layer is a superlattice structure including InN layers and GaN layers. When the pre-grown layer is a superlattice structure including InN layers and GaN layers, the InxGa1-xN well layer is adjacent to a GaN layer of the superlattice structure, and the thickness of the pre-grown layer is more than 0 nm and less than 0.3 nm.