Ac Conductivity Measurement of Cd5Se95-xZnx Chalcogenide Semiconductor Using Correlated Barrier Hopping Model

Cd5Se95-xZnx = 0, 2, 4, 6) chalcogenide semiconductors were prepared by conventional melt-quenching and were characterized by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared studies. Ac conductivity of Cd5Se95-xZnx chalcogenide semiconductor has been investigated in the frequency range of 1 kHz-1 MHz and in the temperature range of 290-370 K. The analysis of the experimental results indicates that the ac conductivity is temperature, frequency and concentration dependent. Ac conductivity is found to obey the power law omega(s) where s < 1. A strong dependence of ac conductivity and exponent s can be well interpreted in terms of correlated barrier hopping model. The maximum barrier height W-m were calculated from the results of dielectric loss according to the Guintini equation that agree with the theory of hopping of charge carriers over potential barrier as suggested by Elliot in case of chalcogenide semiconductors.