Investigation of optical and electrical properties of the semiconducting α-KZnPO 4 compound.

We used the solid state method to synthesize the α-KZnPO 4 compound. The X-ray diffraction pattern revealed that the sample represents a single hexagonal phase with a P 6 3 space group. The chemical composition of the compound was examined by energy dispersive spectroscopy. The optical absorption measurement confirmed the semiconductor nature of the compound with a band gap around 4.52 eV. Furthermore, the electrical properties of the material were analyzed by means of the impedance spectroscopy, in a frequency range from 100 Hz to 1 MHz and a temperature range from 583 K to 673 K. The dependency of s ( T ) on temperature showed that the overlapping large polaron tunneling model is the mechanism responsible for AC conduction in the compound. A correlation between the crystal structure and the ionic conductivity was established and discussed. Finally, the temperature variation of M '' peak showed a thermally activated relaxation process and a temperature-dependent stretching exponent β parameter.