Correlation of Seebeck coefficient and selenization temperature in CuSe thin films grown on glass substrate

Abstract

Copper selenide is emerging as a promising thermoelectric material that has the ability to harvest electricity from heat. In the present research work, copper selenide thin films were grown on glass substrate using thermal evaporation deposition technique. The phase transition from cubic to hexagonal structure was achieved by the selenization of grown samples at different temperatures (250, 300 and 350 °C) for 2 h. The phase, morphology and thermoelectric properties of the selenized CuSe thin films were studied using different characterization techniques. It was observed that the structural, morphological, and thermoelectric properties of the samples were modulated by varying the selenization temperature. XRD results suggested that as grown sample possessed a cubic phase but it transformed into hexagonal phase by selenization process. It was observed that Seebeck coefficient, electrical conductivity and power factor were modulated with the selenization temperature with maximum value of power factor (3.0 × 10⁻⁵±0.5 W m⁻¹C⁻²) was obtained at optimal selinization temperature.