Interdiffusion of GaInNAs/GaAs laser structures

The effects of annealing InGaNAs/GaAs heterostructures on diffusion at the interfaces and the resultant changes in optical and structural properties have been studied. Interdiffusion between In and Ga was found to be obvious. Inserting a thin In_xdGa_1-xdN_ydAs_1-yd layer on either side of an In_xqGa_1-xqN_yqAs_1-yd quantum well (QW) suppressed this interdiffusion significantly. As a consequence, blue shift of the photoluminescence signal after annealing remained small and the optical activity was significantly improved. It was also found that a small amount of N incorporated in InGaAs QWs embedded in GaAs increased In/Ga interdiffusion and that increased mechanical stresses enhanced the interdiffusion.