Observation of Miniband Formation in the CdTe/Cd$_{1-x}$Mn$_x$Te Quantum Well System


We report the effects of perpendicular electric fields on the eigenenergies of the CdTe/Cd$_{1-x}$Mn$_x$Te quantum well system. The samples are probed at 6 K using photoluminescence. In an electric field, the photoluminescence spectra of wide‐barrier quantum well samples red shifted, consistent with the quantum‐confined Stark effect. The spectra of narrow‐barrier superlattice samples blue shifted, indicative of miniband reduction to localized states. A linear blue shift was observed up to a field of 50 kV/cm after which saturation occurred. Additionally, we have observed luminescence which appeared to arise from transitions between adjacent wells. No striking effects were observed at the paramagnetic‐spin glass transition temperature.

Appl. Phys. Lett. 57, 1769 (1990)