Optimizing features of photorefractive devices by tailoring native defects incorporated in the GaAs/AlGaAs multiple quantum wells

To study the influence of defects on device effect, low temperature (LT) grown GaAs/AlGaAs multiple-quantum-wells (MQWs) were grown under different As pressure for the use in a Stark geometry device. The differences in the samples are their defect density in the MQW region. By comparing optical properties, it was found that the optimum device effect coming from high optical quality obtained from samples grown at a critical condition. The detailed defect characteristics and optical properties of the samples with different excess As have been discussed.