Optical Characterization of Interface Behavior in GaAs-GaAlAs Multiple Quantum Well Structures
GaAs-AaAlAs多量子阱界面特性的光学研究

The interface behavior in MBE Grown GaAs-GaAlAs MQW structures has been studied bymeans of photoluminescence and excitation spectrosoopy under extremely low excitation.Differentspectroscopic behavior has been found in different samples.For a sample with singlemonolayer fluctuation, a strong competition between intrinsic exciton luminescence and impurity-relatedemission is observed. However, for the samples with larger fluctuation, the interfacedisorder may become trapping center of excitons, preventing the exciton intralayermigration to impurities, resulting in a single broad intrinsic luminescence peak. On the otherhand the degradation of smoothness of the interface may accumulate impurities on interface,which gives a strong interface-related extrisic emission in the spectrum.