Mechanism of Slow-Mode Degradation in II–VI Wide Bandgap Compound Based Blue-Green Laser Diodes
Abstract
Dislocation-free blue-green laser diodes of (ZnCd)Se/(ZnMg)(SSe) show a “slow-mode” degradation during device operation. This degradation is caused not by generation and propagation of macroscopic defects, but by microscopic-point defect reaction (marked enhancement in its concentration and resulting migration process) during high-density carrier-injection. It is also evidenced experimentally that the direct driving force on the marked defect reaction is derived from minority carrier injection induced e–h non-radiative recombination process at localized point defect centers in the p-type cladding layer of the LD devices.