Temperature-dependent vibrational properties of DVT grown orthorhombic SnS single crystals and their application as a self-powered photodetector

Abstract

Metal chalcogenides have gained global consideration in current decades due to their optoelectronic behaviour, excellent optical absorption and tunable bandgap energies. Specifically, SnS (tin sulfide) crystals have attracted significant attention primarily due to their potential applications in photovoltaic devices, photodetectors, field-effect transistors and holographic recording devices. In this work, we have synthesized SnS (tin sulfide) single crystals using a direct vapour transport technique. The layered type growth mechanism has been observed by a scanning electron microscope (SEM). The X-ray diffractogram pattern reveals the orthorhombic structure and phase purity of grown SnS. The Hall effect measurement confirms the p-type nature of grown SnS crystals and the physical parameters such as carrier concentration, conductivity, mobility and hall coefficient were calculated. Raman measurement at a low temperature ranging from 25 °C to −195 °C was performed, and shifting of vibrational modes have been observed. The parameters, such as the first-order temperature coefficient and peak position at 0 K, are evaluated. The photosensitive property at zero biasing voltage observed under the illumination of 395 nm laser and 670 nm laser. Our results demonstrate that SnS single crystals have great potential for application in photodetection devices.