Cross-sectional TEM study of degraded high power diode lasers

Cross-sectional TEM has been applied to the study of defects in degraded InGaAs/AlGaAs double quantum well (QW) diode lasers. The degradation is due to the formation of a dense band of extrinsic dislocation loops and dipoles in the QW and confinement layers. Nonradiative recombination at the dislocation loops and dipoles is responsible for dark patterns observed in plane view photoluminescence microscopy images. Microdefects detected near the edges of the damaged area on the p-side of the junction are suggested to initiate the generation of dislocation loops. They may be due to supersaturation of Ga interstitials produced either by strain enhanced migration of interstitials or by recombination enhanced diffusion of Mg.