OPTICAL, STRUCTURAL AND ELECTRICAL PROPERTIES OF THE NEW ABSORBER Sn2Sb2S5 THIN FILMS

Sulfosalt Sn2Sb2S5 thin films have been deposited on glass substrates by vacuum evaporation method. The pressure during evaporation was maintained at 10 Torr. The films were annealed in air atmosphere in the temperatures range 100-250°C. The structural and the optical properties have been investigated relating the annealing temperature. Two optical direct transitions were found which decrease by increasing the annealing temperature. Absorption coefficients higher than 10 cm were found. The X-ray diffraction analysis indicates that before and after air heat treatment only the Sn2Sb2S5 phase is present. Furthermore, we found that the Sn2Sb2S5 thin films exhibit N-type conductivity after annealing with lower resistivity. So, the new sulfosalt Sn2Sb2S5 material is a good candidate for example for photovoltaic applications.