Thermal annealing effects on intersubband transitions in (CdS∕ZnSe)∕BeTe quantum wells

Abstract

The authors report the study of thermal annealing effects on intersubband transition (ISB-T) properties of (CdS∕ZnSe)∕BeTe quantum wells (QWs). With the increase of annealing temperature, the ISB absorption wavelength shifts to lower energy and absorption intensity gradually decreases. The dependence of linewidths on the annealing temperature is more complicated and shows opposite trends for the QWs with different well thicknesses. Photoinduced ISB-T measurements indicate that the decrease of ISB absorption intensity results from the loss of free carriers in the well layers. The change of structural properties obtained from x-ray diffraction measurements were used to explain the observed change of ISB absorption characteristics.