DLTS studies of n-type CdTe grown by organometallic vapor phase epitaxy

Deep levels in n-type CdTe layers, grown by OMVPE on InSb substrates, have been investigated using deep-level transient spectroscopy (DLTS). Five levels were detected and four of them appeared on all samples (E2 = 0.36 eV, E3 = 0.65 eV, E4 = 0.74 eV, E5 = 1.15 eV). The dependence of the deep level concentrations on growth conditions provides important information about the origins of these levels. The very deep level E5, which to the authors knowledge has never been observed in previous DLTS studies, is believed to be caused by tellurium vacancies.