ABSTRACT
The hybrid freestanding polyvinyl alcohol (PVA) films embedded with ternary alloy CdZnTe and Ag:CdZnTe were synthesized by in situ chemical method. The modifications in the dielectric properties of PVA films with CdZnTe alloy quantum dot dopants and Ag co-doping were investigated. The dielectric properties and AC conductivity were analyzed over the frequency range from 100 Hz to 4 MHz at room temperature. The frequency dependence of the real and imaginary parts of the dielectric constant, loss tangent, and AC conductivity was examined. Both the real and imaginary parts of the dielectric constant shows frequency dispersions and decreasing tendency toward higher frequencies. The conductivity curves obey Jonscher’s powerlaw and power-law parameters were obtained. The conductivity values fall in the range 10−6–10−7 S/cm for the doped samples. The dielectric and powerlaw parameters were improved for Ag: CdZnTe-PVA freestanding films. The complex impedance plots for CdZnTe-PVA and Ag: CdZnTe-PVA films were analyzed and for both samples, semi-circles were obtained in the higher frequency region. The semi-circles obtained in the complex plots suggest single relaxation process and the possible modeling by an equivalent parallel RC circuit. The Cole–Cole parameters were calculated and higher values were exhibited by Ag:CdZnTe-PVA films when compared to CdZnTe-PVA 270films. The improvements in the dielectric properties indicate that the hybrid freestanding films can be considered as potential candidates as dielectric materials.
