Deposition mechanism and characterizations of CuInS2 film prepared by one-step electro-deposition

Abstract

CuInS2 films had been prepared on FTO using a one-step deposition method, with sodium citrate complexing agent. The film was deposited from the solution containing 20 mmol L−1 CuSO4, 7.5 mmol L−1 In2S3O12, 75 mmol L−1 Na2S2O3 and 8.5 mmol L−1 Na3C6H5O7 for 1200 s. The films were characterized by the UV–visible absorption spectroscopy, SEM, AFM, XRD, XPS methods. By the cyclic voltammetry curves of Cu, S, Cu–S, In, In–S, Cu–In–S, the mechanism of CuInS2 deposition was gotten, that is, the reduction reaction of Cu and In occured, and then S was under potential deposition.