Towards sustainable materials for solar energy conversion: Preparation and photoelectrochemical characterization of Cu2ZnSnS4

The feasibility of a new fabrication route for films of the attractive solar absorber Cu2ZnSnS4 (CZTS) has been studied, consisting of electrodeposition of metallic precursors followed by annealing in sulfur vapour. Photoelectrochemical measurements using a Eu3+ contact have been used to establish that the polycrystalline CZTS films are p-type with doping densities in the range (0.5–5) × 1016 cm−3 and band gaps of 1.49 ± 0.01 eV, making them suitable for terrestrial solar energy conversion. It has been shown that a somewhat Cu-poor composition favours good optoelectronic properties.