Microscopic defect induced slow-mode degradation in II-VI based blue-green laser diodes

Abstract We have studied the microdefect induced degradation mode in long-lifetime blue–green laser diodes (LDs) and light emitting diodes (LEDs) based on II–VI wide bandgap semiconductors. Microscopic deep defect centers in the LDs and LEDs are detected using mainly DLTS technique, coupled with ICTS methods. It is evidenced that a slow-mode degradation, commonly observed in dislocation-free LD devices, is caused by the generation and enhancement of microscopic deep centers during the device aging process. One possible degradation mechanism with a “carrier removal effect” is presented.