Preparation of Cu2ZnSnS4 film by sulfurizing solution deposited precursors

Cu2ZnSnS4 (CZTS) film was obtained by sulfurizing (Cu, Sn)S/ZnS structured precursor that was prepared by a combination of the successive ionic layer adsorption and reaction method and the chemical bath deposition method. Pure Cu2ZnSnS4 phase was obtained when the precursor was annealed at 500 °C for 2 h. The structure, composition, morphology and optical properties of the CZTS film were studied. The results show that the CZTS film has a relatively compact morphology, and the composition of the film is close to the stoichiometric ratio of Cu2ZnSnS4. The film presents a large optical absorption coefficient (larger than 104 cm−1 when the photo energy is beyond 1.47 eV). The optical band-gap of the film is around 1.56 eV. This method is considered a potential way to prepare high quality CZTS film.

► Cu2ZnSnS4 films are prepared by sulfurizing (Cu, Sn)S/ZnS structured precursors. ► The precursors are prepared by a combination of low cost solution methods. ► Pure Cu2ZnSnS4 phase is obtained after annealing the precursor with sulfur vapor. ► The structure, composition and optical properties of the Cu2ZnSnS4 films are studied.