Degradation characteristics of a lighting LED under cooled condition in vacuum and atmospheric environment

摘要

Degradation of LED was investigated through accelerated testing by inducing larger current than a nominal rating under a cooled condition. Onsets on I-V and voltage illuminance characteristics were compared before and after the accelerated testing. Degradation due to a stress induced by larger current resulted in shift of the voltages for the current threshold and the illuminance threshold. Water condensation caused by atmospheric operation of LED testing under cooled condition affected the LED degradation characteristics corresponding to leakage current through adsorbed water.