Physical properties of Sn4Sb6S13 thin films prepared by a glancing angle deposition method

摘要

Sn4Sb6S13 thin films were prepared by thermal evaporation method using Glancing Angle Deposition (GLAD) technique. The incident angle gamma between the particle flux and the normal to the substrate was varied from 0 degrees to 85 degrees. XRD technique and optical measurement are used to study the crystalline structure and optical properties of these films. The X-ray diffraction analysis indicated that the thin films deposited at low incident angle had a monoclinic structure with a preferred orientation along the ((6) over bar 11) plane. However the layers became amorphous at gamma=60 degrees and above. The absorption coefficients and the band gap values of the films were calculated by optical transmission and reflection measurements. It was observed that the optical band-gap values increase from 1.6 eV to 2 eV with increasing the flux incident angle. The prepared thin films have relatively high absorption coefficients between 10(4) and 10(5) cm(-1) in the visible and the NIR spectral ranges. The refractive index and porosity exhibit an opposite evolution as the incident angle gamma rises. At gamma=60 degrees the layers show a maximum of birefringence (Delta n) of 0.062 and a packing density of 0.620. The properties reported here facilitate the use of Sn4Sb6S13 thin films as a potential candidate in many applications such as retardation plate and polarizer. (C) 2015 Elsevier Ltd. All rights reserved.