Influence of temperature on the microcrystalline structure of thermally evaporated Sb 2 S 3 thin films

Thin films of antimony trisulfide (Sb 2 S 3 ) were prepared by thermal evaporation under vacuum (p=5×10 –5 torr) on glass substrates maintained at various temperatures between 293 K and 523 K. Their microstructural properties have obtained by transmission electron microscopy (TEM). The electron diffraction analysis showed the occurrence of amorphous to polycrystalline transition in the films deposited at higher temperature of substrates (523 K). The polycrystalline thin films were found to have an orthorhombic structure. The interplanar distances and unit‐cell parameters were determined by high‐resolution transmission electron microscopy (HRTEM) and compared with the standard values for Sb 2 S 3 . The surface morphology of Sb 2 S 3 thin films was investigated by scanning electron microscopy (SEM). The optical transmission spectra at normal incidence of Sb 2 S 3 thin films have been measured in the spectral range of 400–1400 nm. The analysis of the absorption spectra revealed indirect energy gaps, characterizing of amorphous films, while the polycrystalline films exhibited direct energy gap. From the photon energy dependence of absorption coefficient, the optical band gap energy, E g , were calculated for each thin films. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)