Advancements in Structural Design for Enhanced Performance in AlGaN Deep Ultraviolet Micro-LEDs

This study presents a novel approach to mitigate electron overflow in deep ultraviolet (UV) AlGaN light-emitting diodes (LEDs) by integrating engineered quantum barriers (QBs) with concave shape and an optimized AlGaN superlattice (SL) electron blocking layer (EBL). The concave QBs reduce electron leakage by lowering the electron thermal velocity and mean free path, enhancing electron capture in the active region. The SL EBL further reduces electron overflow without compromising hole transport. At a wavelength of ~253.7 nm, the proposed LED demonstrates a 2.67x improvement in internal quantum efficiency (IQE) and a 2.64x increase in output power at 150 mA injection, with electron leakage reduced by ~4 orders of magnitude compared to conventional LEDs. The efficiency droop is found to be just 2.32%.