Effect of preparation conditions on the properties of Cu ₃BiS₃ thin films grown by a two - Step process

Cu₃BiS₃ thin films were prepared on soda-lime glass substrates by co-evaporation of the precursors in a two-step process; for that, the metallic precursors were evaporated from a tungsten boat in presence of elemental sulfur evaporated from a tantalum effusion cell. The films were characterized by spectral transmittance, atomic force microscopy AFM and x-ray diffraction (XRD) measurements to investigate the effect of the growth conditions on the optical, morphological and structural properties. The results revealed that, independently of the deposition conditions, the films grow only in the orthorhombic Cu₃BiS₃ phase. It was also found that the Cu₃BiS₃ films present p-type conductivity, a high absorption coefficient (greater than 10⁴ cm^-1) and an energy band gap Eg of about 1.41 eV, indicating that this compound has good properties to perform as absorbent layer in thin film solar cells.