Effect of heat treatment on the phase transformation From SnS to pure SnS_2

摘要

SnS_2 nanoparticles were prepared by heat treatment of SnS nanoparticles at 300°C under N_2 atmosphere for 1hour. SnS nanoparticles have been synthesized by chemical precipitation method. As synthesized SnS nanoparticles, for determining the optimal temperature, were heated at various temperatures; 100, 150, 200, 250 and 300°C N_2 atmosphere for lhour. The products are characterized by X-ray diffraction (XRD) , ultraviolet visible (UV-vis) absorbance spectra and photoluminescence (PL). XRD and optical absorption studies show an increase in particle size with increasing heat treatment temperature from 100 to 200°C . However, a large decrease in the nanoparticle size along with transforming from SnS to SnS_2 is observed at 300°C.In addition, the optical properties of al samples , including both UV-vis absorption and emission spectra showed a blue shift as the particles size decreased.