Degradation of III-nitride laser diodes grown by molecular beam epitaxy

摘要

The defects found in electrically degraded GaN-based lasers have been characterised by transmission electron microscopy. In a laser that had been operated until failure, defects containing contact metals were observed. Combined with data from the laser's current-voltage characteristics, this suggests that the catastrophic failure may have been caused by local heating. In partially degraded lasers, four different types of de-fects were observed: cracks, stacking faults, inversion domains and dislocations. Cracks, stacking faults and inversion domains were present before and after the laser failure. The dislocation network, however, was only observed in theac-tive region of a failed laser and may have resulted from re- combination enhanced defect migration.