Ultraviolet light-emitting diode with electron deceleration layer structure

Abstract

The invention discloses an ultraviolet light-emitting diode with an electron deceleration layer structure. The light-emitting diode sequentially comprises a substrate, an AlN nucleating layer, an AlN buffer layer, a non-doped AlGaN buffer layer, an n-type AlGaN layer, a B(Al, Ga)N electron deceleration layer, an Al<x>Ga<1-x>N / Al<y>Ga<1-y>N multi-quantum well active region, a p-type AlGaN layer and a p-type GaN ohmic contact layer from bottom to top. Compared with the Al<x>Ga<1-x>N / Al<y>Ga<1-y>N heterojunction, the B(Al, Ga)N / AlGaN heterojunction has a larger conduction band offset and valence band offset ratio, so that the rate of electrons entering the active region from the n-type region can be limited more effectively. Secondly, a traditional p-type doped electron barrier layer is removed, the efficiency of hole injection into an active region can be improved, and the radiation recombination efficiency of electron holes in the active region is improved. Besides, polarized charges can be generated at the two ends of the B(Al, Ga)N electron deceleration layer, a polarized electric field with the same electron migration direction can be formed, and the migration rate of electrons entering an active region from an n-type region can be reduced, so that the electron capture efficiency of the quantum well is improved, the radiation recombination probability of the electrons and holes in the quantum well is increased, and the light emitting efficiency of the UV-LED is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor optoelectronic materials and device manufacturing, in particular to an ultraviolet light emitting diode (UV-LED) with an electron deceleration layer structure. Background technique [0002] At present, the luminous efficiency of AlGaN-based UV-LED devices is still very low compared with GaN-based blue LEDs, especially in the deep ultraviolet band, and the external quantum efficiency of devices is often lower than 10%. The main reasons for this phenomenon include the low internal quantum efficiency of AlGaN-based UV-LEDs and the high material defect density in AlGaN materials. Among them, the low internal quantum efficiency is mainly related to the lower electron capture efficiency and lower hole injection efficiency in the active region of the UV-LED, making it easy for electrons to escape the shackles of the quantum well and leak into the p-type region and the holes. Perform nonradiative r...

AI Technical Summary

Problems solved by technology

However, the use of this technology not only requires high difficulty in epitaxial growth, but also has limited effects, which is not enough to completely prevent the leakage of electrons to the p-type region, and it is difficult to significantly improve the luminous efficiency of UV-LEDs.

Images