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

Publication date: 1 June 2013
Source:Journal of Crystal Growth, Volume 372
Author(s): Qiang Li , Hongbo Li , Huiqing Fan , Wanqi Jie , Mengmeng Xu , Hairong Wang
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 303–573K. 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±0.005eV, 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±0.03eV) and the activation energy (0.20±0.04eV) 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.