Current Photovoltaic Research ISSN:2288-3274(Print) 2508-125X(Online)

For preparing a device‐quality CuInSe₂ (CISe) light‐absorbing layer by single‐bath electrodeposition for a superstrate‐type CISe cell, morphological properties of the CISe layers were investigated by varying concentrations of sulfamic acid and potassium biphthalate, complexing/buffering agents. CISe films were grown on an In₂Se₃ film by applying a constant voltage of ‐0.5V versus Ag/gCl for 90 min in a solution with precursors of CuCl₂, InCl₃, and SeO₂, and a KCl electrolyte. A dense and smooth layer of CISe could be obtained with a solution containing both sulfamic acid and potassium biphthalate in a narrow concentration range of combination. A CISe layer prepared on the In₂Se₃ film with proper concentrations of complexing/buffering agents exhibited thickness of 1.6~1.8 μm with few undesirable secondary phases. On the other hand, when the bath solution did not contain either sulfamic acid or potassium biphthalate, a CISe film appeared to contain undesirable flake‐shape Cu2‐xSe phases or sparse pores in the upper part of film.