ZnS thin films deposition by thermal evaporation for photovoltaic applications

Zn S thin films were deposited on glass substrates by thermal evaporation from millimetric crystals of Zn S.The structural,compositional and optical properties of the films are studied by X-ray diffraction,SEM microscopy,and UV–VIS spectroscopy.The obtained results show that the films are pin hole free and have a cubic zinc blend structure with(111) preferential orientation.The estimated optical band gap is 3.5 e V and the refractive index in the visible wavelength ranges from 2.5 to 1.8.The good cubic structure obtained for thin layers enabled us to conclude that the prepared Zn S films may have application as buffer layer in replacement of the harmful Cd S in CIGS thin film solar cells or as an antireflection coating in silicon-based solar cells.