Growth of CdTe/CdZnTe strained-layer single quantum wells by modified hot-wall epitaxy method and their properties

Abstract

Several CdTe/CdZnTe strained-layer single quantum well (SLSQW) structures, with CdTe well width ranging from 15 to 240 Å, were grown on GaAs(100) substrates, by modified hot-wall epitaxy (HWE) method for the first time. Our HWE system is equiped with a gold tube radiation shield which is more effective in heat confinement and temperature stability than conventional metal tubes. Photoluminescence (PL) measurements of SLSQW showed that the sharp e 1h 1 excitonic transition peaks in the range of 1.597 to 1.624 eV shifted to the higher energy with decreasing well width. From the PL excitation (PLE) measurements of SLSQW, we obtained the n = 1, 2, 3 and n = 1, 2 excitonic transition peaks for the 240 and 120 Å CdTe well width SLSQW structures, respectively. The excitonic transition energies were calculated considering strain effects and this results were agreed well with experimental ones considering the exciton binding energy. Moreover, the FWHMs of excitonic transition peaks obtained from PL and PLE measurements were about 2 meV and Stokes shifts between PL and PLE spectra were about 1 meV. It indicates that the SLSQWs grown by HWE in this study have a high quality comparable to MBE-grown ones.