Improving AlGaN-based deep-ultraviolet light-emitting diodes: SiO2 passivation and size optimization for enhanced optoelectronic performance

The authors investigate 275-nm AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) of varied dimensions (100, 150, 200, and 300 μm) with or without SiO2 passivation. The results indicate SiO2 passivation significantly enhances the emission intensity and external quantum efficiency in smaller LEDs (100 μm) by mitigating sidewall defects and non-radiative recombination. Conversely, SiO2 passivation adversely affects larger LEDs (150, 200, and 300 μm) due to increased current crowding and heat accumulation. The study emphasizes the tradeoffs between sidewall optimization and heat management in micro-sized DUV LEDs. These insights are critical for the strategic development of efficient DUV LEDs tailored for practical applications.