Investigation of thermal accumulation and lifetime in AlGaN-based UV-C LEDs degradation under current stress

This study delves into the degradation mechanisms of AlGaN-based UV-C LEDs under constant-current stress, focusing on the impact of self-heating and electrical stress. The research identifies three distinct phases of optical power (OP) degradation: an initial stable phase, a short-term rapid degradation phase, and a long-term slow degradation phase. The study establishes a quantitative relationship among device self-heating effects, electrical stress, and OP degradation, leading to the development of mathematical models for lifetime prediction and accelerated testing. The findings reveal that the lifetime of UV-C LEDs is inversely proportional to the seventh power of current density when considering self-heating effects. The research also highlights the critical role of thermal management in enhancing device reliability, offering practical strategies for reliability optimization. The study provides a comprehensive understanding of the complex failure mechanisms in UV-C LEDs, making it an essential read for professionals in the semiconductor and optoelectronics industries.