The effect of anneal temperature on physical properties of SnS films

SnS thin films were deposited on ITO substrates from SnCl2 and Na2S2O3 aqueous solution by pulse electro-deposition method, and the as-prepared SnS thin films were annealed at different temperatures in air for 1 h. The XRD pattern shows that the film decomposed and was oxidized completely at 250 degrees C. The surface morphology and grain size changed with the annealing temperature. The increase of the annealing temperature improved the crystallinity of the deposit and made the scope of absorbed light wavelength larger. Also, the direct energy gap E-g changed with the annealing temperature. The SnS thin films annealed at 100 degrees C have good crystallinity and show strong blue-UV emission, being promising for applications in optical devices. And the band-to-band emission peak (similar to 920 nm) of the SnS thin film indicated the energy gap is 1.37 eV. (C) 2008 Elsevier B.V. All rights reserved.