Structural and optical properties of SnS2 nanosheets for Opto-electronic devices

Tin disulfide (SnS 2 ) is a promising material for applications in photodetectors, hydroelectric cells, photovoltaics, and energy storage owing to its layered structure, excellent optical and electrical properties, and high chemical stability. In this study, SnS 2 nanosheets were fabricated using the sol-gel technique, a method known for its efficiency in producing high-purity nanostructures on a large scale at a reasonable cost. To produce the final SnS 2 nanosheets, a precursor solution consisting of Sn and sulfur sources was prepared. This was followed by careful hydrolysis of Tin (IV) chloride pentahydrate with thiourea, forming a gel, which was dried and annealed to form crystalline SnS 2 nanosheets. X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, and Photoluminescence spectroscopy (PL) were used to investigate the structural, morphological, chemical-bond, optical and electrical characteristics of the produced SnS 2 . While TEM and Selected area electron diffraction (SAED) revealed well-ordered nanosheets with high crystallinity and a lattice spacing of 0.58 nm, the XRD investigation verified the production of a pure hexagonal SnS 2 phase. UV-Vis spectroscopy estimated a band gap of 2.37 eV. PL spectra showed a prominent emission peak at 699 nm, suggesting a direct bandgap transition suitable for optoelectronic devices. The CIE coordinates of (0.258, 0.286), which fall in the bluish-cyan region of the chromaticity diagram, confirming a bluish emission, suitable for optoelectronic devices. FTIR analysis of sol-gel-synthesized SnS 2 confirmed the presence of Sn-S bonds, indicating successful compound formation. According to these estimations, the optical band gap falls within the range appropriate for optoelectronic applications. The Electrical studies demonstrated a carrier concentration of 8.6 × 10 15 cm -3 and high mobility of 218 cm 2 /V.s. A photodetector fabricated using the Ag/SnS₂/ITO-glass heterostructure exhibited excellent photoresponse, with responsivity of 530 mA/W and an external quantum efficiency of 96.9% under 680 nm illumination. These findings establish sol–gel-derived SnS₂ nanosheets as a versatile and efficient material platform for advanced optoelectronic and energy-harvesting devices.