Structure of deep ultraviolet light emitting diode and preparation method thereof

The invention discloses a deep ultraviolet light-emitting diode structure and a preparation method thereof, and aims to improve the electroluminescent spectral characteristics of the current deep ultraviolet light-emitting diode, especially reduce the full width at half maximum of the spectrum, improve the purity of light and improve the luminous efficiency of the light. Therefore, the effectiveness of application to sterilization and phototherapy is promoted. The light-emitting diode at least comprises a substrate, an AlN layer located on the surface of one side of the substrate, an N-type AlaGa1-aN ohmic contact layer located on the surface of the AlN layer, an AlbGa1-bN/AlN/AlcGa1-cN interface planarization multi-layer structure located on the surface of the N-type AlaGa1-aN ohmic contact layer, an AlxGa1-xN first quantum barrier layer located on the surface of the AlbGa1-bN/AlN/AlcGa1-cN interface planarization multi-layer structure, an AlyGa1-yN/AlxGa1-xN multi-quantum well active layer located on the su