Photoelectrochemical deposition of ZnO films via nitrate ions reduction in the presence of thiourea on p-type Cu(In,Ga)Se2 semiconducting electrodes for photovoltaic applications

This work describes the electrodeposition of ZnO layers on p-type copper indium gallium diselenide [Cu(InGa)Se2] substrates via nitrate ions reduction in the presence of thiourea. The substrate stability domain has been determined by means of cyclic voltammetry in acidic medium. The optimal deposition range has been studied in zinc nitrate electrolyte containing concentrations of thiourea between 0 and 1.0 M. Zinc oxide films have been photoelectrodeposited in a potential range between − 0.95 and − 1.1 V/MSE depending on thiourea concentration. The morphology and composition analyses by scanning electron microscopy, X-ray diffraction spectroscopy, and energy dispersive X-ray spectroscopy have highlighted that the deposited films are composed of well-crystallized ZnO presenting wurtzite-type structure with no significant sulfur incorporation.