Influence of Citrate Ions as Complexing Agent for Electrodeposition of CuInSe2 Thin Films

Abstract

The preparation of CuInSe2 thin films by electrodeposition is studied. The effect of sodium citrate (Na3C6H5O7) as complexing agent on the electrodeposition of pure copper, indium, selenium and of their ternary alloy is emphasized. Cathodic shifts of the copper and selenium electrodeposition potentials with increasing citrate concentration are observed. On the contrary, the presence of citrate in the electrolyte does not change the indium electrodeposition potential but improves its crystallinity. The surface morphology and the composition of the deposited films are characterized by scanning electron microscopy (SEM). The texture of the deposits and their compositions are analyzed by X-ray diffraction. The formation of CuInSe2 films with a chalcopyrite structure and good stoichiometry is observed.