Light emitting diode chip and preparation method thereof

The invention provides a light-emitting diode chip and a preparation method thereof. The light-emitting diode chip comprises a substrate, and a buffer layer, an n-type GaN layer, an active layer and a p-type GaN layer which are sequentially deposited on the substrate, a plurality of nano grooves are formed in the p-type GaN layer, SiO2 grooves are formed in the nano grooves, a first Ag metal layer is arranged in the SiO2 grooves, a SiO2 layer and a second Ag metal layer are sequentially arranged on the part, not provided with the nano grooves, of the p-type GaN layer, an ITO layer is arranged on the first Ag metal layer and the second Ag metal layer, an electrode layer is arranged on the ITO layer and the n-type GaN layer, and an electrode layer is arranged on the n-type GaN layer. According to the invention, the SPP can be effectively excited and is strongly coupled with the quantum well in the active layer, the IQE of the light emitting diode chip is greatly improved, and the SPP extraction efficiency and t