Electrodeposition of CuInTe₂ film from an acidic solution

Copper-indium-telluride films were electrochemically deposited from solutions containing CuCl₂, InCl₃, TeO₂ and HCl. Although a flat and smooth film with closely stoichiometric composition was deposited at -660 mV vs. Ag/AgCl at 303 K from a solution of 2.5×10^-4 mol dm^-3 CuCl₂, 1.0×10^-2 mol dm^-3 InCl₃, 5.0×10^-4 mol dm^-3 TeO₂ and 0.1 mol dm^-3 HCl, a polycrystalline CuInTe₂ film was not obtained. Increasing the temperature from 303 to 363 K allowed the deposition at lower overpotential of a polycrystalline CuInTe₂ film with closely stoichiometric composition and increased indium content. The band gap of the polycrystalline CuInTe₂ film electrodeposited at 363 K at -660 mV was 0.98 eV.