Post-deposition thermal treatment of sprayed SnS films

Publication date: Available online 10 January 2017
Source:Thin Solid Films
Author(s): S. Polivtseva, A. Katerski, E. Kärber, I. Oja Acik, A. Mere, V. Mikli, M. Krunks
SnS films were grown by the chemical spray pyrolysis method using aqueous solutions containing SnCl2 and SC(NH2)2 at molar ratios of 1:1 and 1:8 in air at a substrate temperature of 200°C. As-deposited films were thermally treated at 450°C in nitrogen and vacuum atmospheres. All samples were studied using X-ray diffractometry, Raman spectroscopy, energy-dispersive X-ray analysis, and ultraviolet–visible spectroscopy. The as-grown films consisted of cubic SnS as the only crystalline phase regardless of the molar ratio of the precursors in the spray solution. Annealing of the 1:1 films (derived from the 1:1 solution) in vacuum yielded metallic Sn, whereas annealing in N2 produced films composed of a mixture of cubic SnS and SnO2 phases, indicating the presence of oxygen-containing non-crystalline phases in the as-grown films. Thermal treatment of the 1:8 films in nitrogen yielded films composed of Sn2S3, whereas vacuum annealing produced films consisting of orthorhombic SnS with a bandgap energy of 1.4eV.