Carrier Dynamics Study of CdxZn1-xSe/ZnSe (x = 0.2) Multiple Quantum Wells
In this paper, nonlinear optical properties of CdxZn1-xSe/ZnSe (x = 0.2) multiple quantum wells were studied by low temperature steady-state and transient photoluminescence at high excitation densities. The biexciton transition was observed on the low energy side of the exciton transition. Based on the characteristics of stimulated emission observed in similar structures, we suggest the biexciton transition as the mechanism for stimulated emission. Optical degradation was also studied by room temperature photoluminescence using femtosecond laser pulses as the excitation source. The results confirm the formation of nonradiative recombination centers with a saturating degradation effect after about 10 min of exposure.