Impurity process in ZnCdSe/ZnSe multiple quantum wells

Abstract

At high excitation intensity the photoluminescence (PL) spectra of ZnCdSe/ZnSe multiple quantum wells were studied, which showed strong excitonic emission and a broad emission band at low energy side. The dependence of the broad emission band on excitation intensity shoed obviously that the broad emission band is related to impurity. In time resolved luminescence spectra, with increasing the delay times (ns), the broad emission band shifts to low energy side and full width at half maximum decreased, which showed the typical characteristic of donor-acceptor pairs (DAP) emission. And then, the reason that the excitonic emission peak and the DAP band decay with same speed was discussed and it was attributed to the free carriers relax effect.