A review on degradation physics of high power LEDs in outdoor applications

摘要

High power LEDs are replacing the traditional lighting sources due its wide range of advantages. However, their reliability remain a concern due to the lack of understanding in terms of their failure mechanisms and related reliability studies, especially in outdoor applications. In this work, a comprehensive review on the study of humidity and high temperature based degradation mechanisms for high power LEDs is reported. The failure mechanism is found to vary at various humidity levels as well as during their life cycles. This renders the existing lifetime prediction models inapplicable for high power LEDs.