Characteristics of CuInSe₂ nanowire arrays electrodeposited into anodic alumina templates with dimethyl sulfoxide (DMSO) additive

We successfully fabricated ternary CuInSe2 nanowire arrays in a novel acidic Dimethyl sulfoxide (DMSO)-aqueous electrolyte using pulse electrodeposition techniques with the assistance of an anodized aluminum oxide (AAO) template and investigated the effects of deposition potential and a DMSO additive on the composition and crystallization of CuInSe2 nanowires. We obtained the near-stoichiometric CuInSe2 nanowires by tuning the deposition potential at -1.0 V. The addition of DMSO into the electrolyte significantly affects the pore-filling ratio and the growth rate of CuInSe2 nanowires. The detailed microstructure of CuInSe2 nanowires were obtained from the transmission electron microscopy (TEM) analysis, which shows the polycrystalline nature of CuInSe2 nanowires regardless of the electrolyte with and without DMSO. Proposed mechanism for the growth mechanism of nanowires deposited in the electrolyte with DMSO was presented on the basis of kinetic and thermodynamic process. Photoelectrochemical (PEC) characterizations showed that the CuInSe2 nanowires deposited in the electrolyte containing 0.5 mM DMSO exhibited a superior photocurrent response than the CuInSe2 nanowires deposited in the electrolyte without DMSO.