Properties of photoluminescence in type-Ⅱ ZnMnSe/ZnSeTe multiple quantum wells

摘要

The optical properties of type-Ⅱ ZnMnSe/ZnSeTe multiple quantum wells were investigated by photoluminescence (PL) measurement. It was found that the peak position of PL spectra shows a giant blueshift under a moderate optical excitation level. The giant blueshift can be interpreted in terms of the band-bending effect due to the spatially photoexcited carriers in a type-Ⅱ alignment. We also found that the PL spectra exhibit a large in-plane polarization with respect to <110> axis with the polarization degree up to 12.4%. We showed that the polarization does not depend on the excitation intensity as well as temperature, which excludes the possibility of extrinsic mechanisms related to the in-plane anisotropy. The observed anisotropic effects of ZnMnSe/ZnSeTe multiple quantum wells were attributed to the intrinsic property of the orientation of chemical bonds at the heterointerface of the type-Ⅱ band alignment.