Influence of Grain Size on the Band-gap of Annealed SnS Thin Films

The manuscript reports the variation in optical band-gap of vacuum annealed SnS thin films. The samples were characterized by using X-Ray Diffraction, UV-visible Spectroscopy and Raman Analysis. Results show that while annealing does not effect the nano-crystalline sample's lattice structure or unit cell size it does control the grain size. The band-gap (Eg) decreases with increase in grain size. Eg values were found to be very high (1.8-2.5 eV) for samples studied.