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

Abstract

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.

Photoluminescence Characterization of Type-II Zn0.97Mn0.03Se/ZnSe0.92Te0.08 Multiple-Quantum-Well Structures

“…5) In power-dependent PL spectra, a giant blue shift of the PL peak energy was found and explained by the band-bending and band-filling effects. 6) On the basis of these experimental results, a square potential well with a depth of 0.6 eV in the valence band and a triangular well in the conduction band were proposed.…”