Structure and properties of electrodeposited films and film stacks for precursors of chalcopyrite and kesterite solar cells

A comparative analysis of the structure and surface morphology of copper, indium, tin, and zinc films and their layered compositions fabricated by electrochemical deposition in the galvanostatic steady-state mode, galvanostatic mode with the ultrasonic agitation of electrolytes, and forward and reverse pulsed modes with rectangular potential pulses is made. The effect of the electrodeposition modes on the structure, optical properties, and surface morphology of amorphous and crystalline selenium films is studied. Cu/In/Se and Cu/Sn/Zn/Se film compositions, which are model precursors of, respectively, chalcopyrite CuInSe$_2$ and kesterite, are fabricated by successive electrochemical deposition. Upon being converted by subsequent annealings to CuInSe$_2$ and Cu$_2$ZnSnSe$_4$ semiconductor materials, these precursors will be used as the base layers for a new generation of inexpensive high-efficiency thin-film solar cells.