ACTIVATION-ENERGY OF NONRADIATIVE PROCESSES IN DEGRADED II-VI LASER-DIODES

A spatially resolved cathodoluminescence study of [100] dark line defe cts (DLDs) of degraded II-VI laser diodes based on a ZnCdSe/ZnMgSSe se parate confinement heterostructure has been carried out at temperature s between room temperature and 8 K. Cathodoluminescence line scans wer e used to measure the change of contrasts between the DLDs and the adj acent material. The contrast decreased with decreasing temperature, wh ich suggests that the nonradiative recombination processes associated with DLDs are thermally activated. Activation energies were found to b e about 16 and 6 meV for temperatures above and below 200 K, respectiv ely, which may reflect a transition between free carriers and bound ex citons at this temperature. (C) 1997 American Institute of Physics.