A New Degradation mechanism for 0.98microns In sub x Ga sub (1-x) As/GaAs Strained Quantum Well Lasers

We have observed In out-diffusion from strained In sub x Ga sub (1-x) As quantum well into the adjacent GaAs barriers in degraded 0.98microns wavelength strained quantum well lasers for the first time. A previous calculation on misfit stress induced compositional instability indicated that this material system is stable with respect to misfit strain. Therefore the out-diffusion of In from In sub x Ga sub (1-x) As quantum well is mainly driven by the compositional discontinuity across the well/barrier hetero-interfaces, and is believed to be activated by the non-radiative recombination of injected carriers.