Sn2Sb2S5 films for photovoltaic applications

In this paper we propose that Sn 2 Sb 2 S 5 is one of the main candidates of thin film absorbers materials. Sulfosalt Sn 2 Sb 2 S 5 thin films have been deposited on glass substrates by vacuum evaporation method. The pressure during evaporation was maintained at 10 -5 Torr. The films were annealed in air atmosphere in the temperatures range 100-250°C. Two optical direct transitions were found. Absorption coefficients higher than 10 4 cm -1 were found. The X-ray diffraction analysis indicates that before and after annealing only the Sn 2 Sb 2 S 5 phase is present. Sn 2 Sb 2 S 5 thin films exhibit N-type conductivity after annealing. We present a model that helps to explain the evolution of photovoltaic effect.