Enhanced electrical and optoelectronic performance of SnS crystal by Se doping

Abstract

In the current decade, Metal chalcogenides have achieved immense importance due to their tunable bandgaps, excellent optical absorption and outstanding optoelectronic behavior. Specifically, pristine and doped SnS (tin sulfide) crystals have fascinated noteworthy consideration mainly due to their potential applications in photodetectors, photovoltaic devices, holographic recording devices and field-effect transistors. In that view, selenium doped tin sulfide crystals were synthesized by direct vapor transport (DVT) technique. The elemental composition was confirmed by energy dispersive analysis of X-ray (EDAX). The structural characterization reveals a layer type growth mechanism of grown SnS0.25Se0.75 crystals. The powder X-ray diffraction reveals the orthorhombic phase and high crystallinity of synthesized crystals. X-ray photoelectron spectroscopy analysis confirmed the formation of SnS0.25S0.75 structure and binding energy of the elements in the samples. The temperature dependent in-plane and out-of-plane resistivity measurements determined the anisotropic charge conduction of grown crystals. The carrier concentration and mobility came out to be 6.19 × 1015 cm−3 and 31.48 cm2 V−1 s−1 calculated from hall effect measurement. The photosensitive properties of SnS0.25Se0.75 crystal-based photodetector were also investigated under different biasing conditions. The device exhibited an excellent response time of 0.6 s along with good photocurrent and responsivity as compared with previous reports. Additionally, air stability after 1 month under 0 V and 1 mV biasing have been reported. This study assigned that Se doping played a major role in enhancing optoelectronic properties and the composition can be used in potential optoelectronic devices for future applications.