Synthesis and Characterization of SnS Flake-like Microcrystals with a Microwave Hydrothermal Processing

摘要

SnS powders were obtained by the microwave hydrothermal (M-H) systhesis technique using SnCl_2?2H_2O and CH1CSNH2 as precursors. By changing the M-H processing temperature, SnS crystallites with differernt sizes and morphologies could be achieved. The phase compositions, microstructures and optical properties of the-prepared SnS crystallites were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), UV-Vis spectroscopy and photolumincscence spectroscopy (PL). Results show that the SnS powders present a herzenbergite-type orthorhombic structure and free of secondary phases. FE-SEM images indicate that the composite crystals are stacked with smaller flake-like crystals. By UV-Vis spectra analysis, the optical band gap of SnS powders is about 1.48 eV, which shows a blue shift of 0.18 eV compared to the bulk SnS. A near-infrared photoluminescence (PL) emission (830 nm) at room temperature is verified for the SnS powders when exited by 551 nm wavelength.