Synthesis and characterization of peculiar (Sb0.2Sn0.8)0.5(Se0.9S0.1)0.5 crystal and its application as visible light photo-detector

Abstract

To investigate the influence of Sb and S inclusion on SnSe characteristics, alloy engineering is carried out. The (Sb0.2Sn0.8)0.5(Se0.9S0.1)0.5 quaternary crystal was well synthesized via direct vapour transport (DVT) technique. The surface morphology, chemical composition, structural, optical, electrical, and photoconductive characteristics of the grown crystal were estimated using acceptable methodologies. The FE-SEM image revealed that the (Sb0.2Sn0.8)0.5(Se0.9S0.1)0.5 crystal has a flat surface, and the chemical composition was established using EDAX. X-ray diffraction (XRD) spectra further validated the orthorhombic structure of the crystal. Raman spectroscopy was employed to find different vibrational modes. The crystal exhibits a direct bandgap of 1.42 eV. The four-probe method and hot point probe method examination revealed the crystal to be an n-type semiconducting material. Additionally, an analysis of the pulsed photo response was carried out on the grown crystal, which was exposed to different wavelengths and white light at varying intensities, while subjected to a biasing voltage of 1 V, with an on/off period of 10 s. The results indicated that the device demonstrated rapid response to incident light, along with the presence of a trapping state, and favourable photodetection parameters, making it a viable material for a visible light photodetector.