Dielectric properties of Zn1-xMnxTe epilayers

We report on the dielectric properties of Zn1-xMnxTe (0less than or equal toxless than or equal to0.268) epilayers studied by capacitance and dissipation factor measurements at a temperature of 200 K<T<460 K and a frequency of 20 Hz<f<1 MHz. A Debye-like relaxation in the dielectric response has been observed, which is explained in terms of the presence of charge redistribution. The relaxation is found to be a thermally activated process, and the activation energies obtained from both dissipation factor and capacitance are in good agreement. It is also found that the activation energy decreases with increasing Mn content and this behavior is interpreted in terms of the four-center model, in which the number of Mn atoms appearing in the nearest-neighbor sites of a defect can have four possible configurations. In addition, we demonstrate that the mechanism responsible for the conduction of carrier hopping among structural defects can be attributed to the correlated barrier hopping model. (C) 2003 American Institute of Physics.