Effects of sodium sulfamate on electrodeposition of Cu(In,Ga)Se2 thin film

Cu(In,Ga)Se2 thin films have been prepared by electrodeposition from chloride electrolytes using sodium sulfamate as a complexing agent. Cyclic voltammograms indicate that sodium sulfamate can inhibit the reduction of Cu2+, Cu+ and H2SeO3, and accordingly hinder the formation of copper selenides. EDS analysis reveals that with the increase of sodium sulfamate concentration in the bath, atom ratio (Cu + Se)/(In + Ga) decreases while gallium content increases, and the film composition transforms from Cu-rich to Cu-poor. SEM and Raman spectra also show that copper selenides phases in electrodeposited films diminish with the increase of sodium sulfamate concentration.