Electrical Conductivity, Thermoelectric Power, and Thermal Conductivity of Bi29Tl35Se36 Chalcogenide Glass Semiconductors in Solid and Liquid States

Abstract

The properties of chalcogenide glass semiconductors of Bi29Tl35Se36 is investigated by the electrical conductivity, thermoelectric power and thermal conductivity as a function of temperature from room temperature to near 500°C. The experimental data of the electrical conductivity and thermoelectric power are analyzed in terms of a model developed from the density of states and electrical transport in solid amorphous semiconductors[1]. The activation energy calculated from electrical conductivity data is found to be 0.11 eV for the solid and 0.66 eV for the liquid. Moreover, the coefficient of the linear decrease of energy gap with temperature was found to be γ=10.37 ×10−4eV/K°. Measurements of the thermal conductivity of our sample were carried out from the room temperature to near 500° C. These measurements of thermal conductivity were carried out using the concentric cylinder method. The temperature dependence of the thermal conductivity was explained by postulating different mechanism[2] for (λ) in semiconductors. Values of room temperature electronic and bipolar thermal conductivity [λe(30) and λbp(30)] for the investigated sample were calculated, moreover these values estimated at 0° C. The thermal conductivity due to atomic motion (λa) also is calculated. Also the thermoelectric Q-factor (Z) is calculated for our sample in solid and liquid states.