Effects of Annealing on Thermally Evaporated SnSe Thin Films

SnSe alloy in alkaline medium was synthesized at 100 degrees C using SnCl2 center dot 2H(2)O and selenium as source materials. The powder X-ray diffraction patterns recorded for synthesized product confirmed the formation of nanocrystalline SnSe material. The synthesized SnSe was made as pellets and used as the source materials for the deposition of SnSe thin films on the glass substrate by thermal evaporation method at room temperature (RT) and at various substrate temperatures of 150 degrees C, 250 degrees C, 350 degrees C and 450 degrees C. The deposited films were annealed at 450 degrees C for 30 min under the vacuum of similar to 10(-5) Torr. The effects of annealing on the structural and optical properties of the as deposited SnSe films are reported in this article. Scanning Electron Microscopy shows the modification in surface morphology of SnSe thin films due to annealing. Annealing of the films reduces the transmittance and enhances optical band gap of SnSe films.