Investigation of the structural, optical and thermoelectric performances of flash-evaporated cobalt-doped copper sulfide thin films

Abstract

In this study, we employed the flash evaporation method to deposit thin films of pure copper sulfide and cobalt-doped copper sulfide. We focused on evaluating the influence of cobalt content, ranging from zero to 9%, on the structural, optical, electrical, and thermoelectric characteristics of the synthesized thin films. Our findings indicate that the passage from the copper-rich (covellite phase to the digenite or djurleite phases) can be carried out by annealing or by doping. Raman's investigation supports the discovered phase and shows that the A1g(LO) mode intensity drops with doping. The gap energy was found to decrease by increasing the percentage of cobalt. The annealing at 350 °C resulted in good thermoelectric properties, while the dominance of the djurleite phase, resulted in the highest Seebeck coefficients.