Optical and Raman scattering studies on SnS nanoparticles

Tin sulfide nanoparticles were synthesized through wet chemical route. Structure and phase purity were confirmed by powder XRD. Morphology and size were identified from TEM and AFM. The room temperature photoluminescence spectrum shows the band edge emission at 1.57 eV. The direct and indirect band gaps are estimated from UV–vis-NIR absorption spectrum as 1.78 and 1.2 eV, respectively. Blue shift of 0.48 eV observed for direct transition and 0.2 eV for indirect transition as compared to bulk band gap is due to quantum confinement effect. The Raman spectrum of SnS nanoparticles shows all the predicted Raman modes which show shift towards lower wave number side in comparison with those of the SnS single crystal. This is attributed to phonon confinement.

► The room temperature photoluminescence spectrum showing direct band edge emission.
► Estimation of the direct and indirect band gaps from UV–vis-NIR absorption spectrum.
► Raman spectrum of SnS nanoparticles showing all the predicted Raman modes.