The Effect of the Growth Condition on the Properties of the New Material Sn3Sb2S6 Thin Films

Sulfosalt Sn3Sb2S6 material was synthesised by the horizontal Bridgman method. X-rays diffraction analysis of the powder showed that only homogenous Sn3Sb2S6 phase is present in the ingot. Sn3Sb2S6 thin films were deposited by a single source vacuum thermal evaporation with different thicknesses on glass substrates. The optical and structural properties of the films were studied as a function of thicknesses and temperature substrates. It is interest to note that Sn3Sb2S6 films exhibit polycrystalline structures along (416) preferred plane without heating the substrates. In addition, we note that as the thickness increases from 150 nm to 430 nm the average grain size increases from 190 to 350 °A. The samples have direct bandgap energies of 1.5 - 1.75 eV. Furthermore, we found that the absorption coefficient in all cases reached 104 cm−1. So, Sulfosalt Sn3Sb2S6 thin films could be used as a potential candidate in may technological applications such as photovoltaic solar cell

Effect of vacuum annealing on structural, morphological and optical properties of Sn

Sn2Sb2S5 thin films in thickness of 100–900 nm were deposited on unheated glass substrates using thermal evaporation method and annealed in vacuum at temperature of 200 °C for 2 h. X-ray diffraction spectra indicated that all the Sn2Sb2S5 samples are polycrystalline in nature having orthorhombic structure. The various structural parameters, such as, crystalline size, dislocation density, strain and texture coefficient were calculated and the surface morphology of the films was also analyzed. The optical constants, i.e., refractive index, absorption coefficient and optical band gap of the as-deposited and post-annealed films have been determined from the analysis of the transmittance and reflectance spectral data over the wavelength range 300–1800 nm. All the Sn2Sb2S5 thin films before and after annealing have relatively high absorption coefficient between 104 and 105 cm−1 in the visible spectral range. The optical band gap was found to decrease, from 1.72 to 1.5 eV for samples before annealing and from 172 to 1.46 eV for samples annealed in vacuum, with increasing films thickness in the 100–900 nm range