Deep ultraviolet led and method for producing the same

Abstract

A deep ultraviolet LED with a design wavelength λ, including a reflecting electrode layer (Au), a metal layer (Ni), a p-GaN contact layer, a p-block layer made of a p-AlGaN layer, an i-guide layer made of an AlN layer, a multi-quantum well layer, an n-AlGaN contact layer, a u-AlGaN layer, an AlN template, and a sapphire substrate that are arranged in this order from a side opposite to the sapphire substrate, in which the thickness of the p-block layer is 52 to 56 nm, a two-dimensional reflecting photonic crystal periodic structure having a plurality of voids is provided in a region from the interface between the metal layer and the p-GaN contact layer to a position not beyond the interface between the p-GaN contact layer and the p-block layer in the thickness direction of the p-GaN contact layer, the distance from an end face of each of the voids in the direction of the sapphire substrate to the interface between the multi-quantum well layer and the i-guide layer satisfies λ/2n(where λ is the design wavelength and n1Deff is the effective average refractive index of each film of the stacked structure from the end face of each void to the i-guide layer) in the perpendicular direction, the distance being in the range of 53 to 57 nm, the two-dimensional reflecting photonic crystal periodic structure has a photonic band gap that opens for TE polarized components, and provided that the period a of the two-dimensional reflecting photonic crystal periodic structure satisfies a Bragg condition with respect to light with the design wavelength λ, the order m of a formula of the Bragg condition: mλ/n=2(where m is the order, λ is the design wavelength, nis the effective refractive index of two-dimensional photonic crystals, and a is the period of the two-dimensional photonic crystals) satisfies 2≤m≤4, and the radius of each void is R, R/a satisfies 0.30≤R/a≤0.40.