Optical properties of nanocrystalline SnS2 thin films

Thin films of nanocrystalline SnS{sub 2} on glass substrates were prepared from solution by dip coating and then sulfurized in H{sub 2}S (H{sub 2}S:Ar = 1:10) atmosphere. The films had an average thickness of 60 nm and were characterized by X-ray diffraction studies, scanning electron microscopy, EDAX, transmission electron microscopy, UV-vis spectroscopy, and Raman spectroscopy. The influence of annealing temperature (150-300 deg. C) on the crystallinity and particle size was studied. The effect of CTAB as a capping agent has been tested. X-ray diffraction analysis revealed the polycrystalline nature of the films with a preferential orientation along the c-axis. Optical transmission spectra indicated a marked blue shift of the absorption edge due to quantum confinement and optical band gap was found to vary from 3.5 to 3.0 eV with annealing temperature. Raman studies indicated a prominent broad peak at {approx}314 cm{sup -1}, which confirmed the presence of nanocrystalline SnS{sub 2} phase.