Abstract CuInSe 2 (CIS) thin films were deposited on Mo/glass substrates by one-step electrodeposition from aqueous baths containing CuSO 4, In 2(SO 4) 3 and SeO 2 with Li 2SO 4 electrolyte. The quality of the electrodeposited films depended on the presence of pH buffer in the bath. CIS films deposited from non-pH buffered baths showed pronounced (112) orientation, while films exhibiting more random orientation were obtained from pH buffered baths. Denser, smoother samples were obtained from non-pH buffered baths, though with no difference in film composition. As-deposited films exhibit low crystallinity and require recrystallization by annealing in H 2Se. Best devices, ∼ 9%, were obtained with CuInSe 2 films deposited from non-pH buffered baths.