Simulation of AlGaN-based DUV-LED with The Variation of Step Al-graded QWs Configuration

Abstract

Analysis of aluminum composition grading is presented to enhance the efficiency of AlGaN-based deep ultraviolet light emitting diodes (DUV-LEDs).  The optical performance of LEDs with varying quantum well (QW) thickness and aluminum composition grading were examined through drift-diffusion simulations.  All LEDs featured step-graded QWs from 0.43 to 0.45 aluminum composition and have a total QW thickness of 3 nm, with thickness variations occurring at different aluminum composition gradings.  Compared to LEDs with 0.5 nm and 1 nm QW thickness at an aluminum composition grading of 0.43, the LED with 1.5 nm demonstrated a high internal quantum efficiency (IQE) of 53.06%.  The LED emitted at 283.327 nm.  This design mitigated polarization effects, enhanced carrier injection efficiency, and improved carrier transport within QWs. This, in turn, increased the radiative recombination rates and luminescence intensity of the LEDs.