Electrical conduction behavior and hopping rates estimate of cadmium zinc telluride single crystal

CdZnTe (CZT) single crystal was grown by a modified vertical Bridgman method. It was used to study the electrical conduction behavior of CZT crystal by impedance spectroscopy in the temperature range over 303-573 K. The imaginary part vs real part of complex impedance plots was considered to be a semicircle indicating only bulk contributions. The value of activation energy derived from the peak of the imaginary part of electrical impedance was found to be 0.08 +/- 0.005 eV, which was assigned to relate the migration and hopping of ionized Cd vacancies and Te antisites. The discrepancy between activation energy of dc electrical conductivity (0.35 +/- 0.03 eV) and the activation energy (0.20 +/- 0.04 eV) of hopping rates was attributed to the high ion hopping rates and low attempt frequencies. The mechanism of electrical conduction was mainly ascribed to a short range migration or hopping of charge carriers including ionized Cd vacancies and Te antisites in the CZT crystal system. (C) 2013 Elsevier B.V. All rights reserved.