PHOTOREFLECTANCE STUDY OF GaAs/AlGaAs MULTI-QUANTUM WELLS

Using photoreflectance (PR) at room temperature, we have studied GaAs/AlGaAs multi-quantum wells(MQWs) grown by molecular beam epitaxy. Analysis shows that the modulation mechanism of PR of MQWs is Stark shift of the subbands produced by photo-injection of carriers, which has first derivative functional lineshapes. By fitting the experimental spectra, an unusual transition coming from the interfaces in MQWs was observed.