Deep-level transient spectroscopy and cathodoluminescence of CdxZn1-xTe/ZnTe QW structures grown on GaAs(100) by MBE

MBE-grown ZnTe/CdZnTe/ZnTe strained single quantum well (SQW) and multiple quantum well (MQW) structures with non-doping layers were investigated by c athodoluminescence (CL) and deep-level transient spectroscopy (DLTS). The D LTS method with electrical current relaxation was used because the as-grown structures were compensated. The activation energies of 0.21 and 0.58 eV f or deep levels in ZnTe buffer layers grown on GaAs were determined by the D LTS spectra. Besides, an additional DLTS peak (E-t = 34-133 meV) that depen ds on the quantum well parameters and correlates with the QW emission line position in the CL spectra was observed. This peak is interpreted as an emi ssion of electrons from a ground level of dimensional quantization in a con duction band. Obtained DLTS and CL results were used for an estimation of a conduction-band offset parameter Q(c). (C) 2000 Elsevier Science B.V. All rights reserved.