Hydrothermally synthesized dual-functional tin (II) sulfide nanoparticles: Photonic response and pressure sensing applications

Tin (II) sulfide (SnS) nanoparticles exhibit notable characteristics such as a direct band gap, non-toxicity, and cost-effectiveness, making them attractive for diverse applications. This research focuses on synthesizing SnS nanoparticles using a budget-friendly hydrothermal method and conducting comprehensive characterization. Energy-dispersive X-ray spectroscopy and scanning electron microscopy analyses confirmed the high purity and orthorhombic-like structure by examining composition and surface morphology. High resolution transmission electron microscopy with selected area electron diffraction was carried out for plane validation. X-ray photoelectron spectroscopy implies the energy levels of Sn and S, aiming to determine binding states and chemical composition. X-ray diffraction provided detailed information on the crystallographic parameters with 30.80 nm crystallite size. Ultraviolet–Visible spectroscopy indicated a band gap of 1.62 eV, suitable for light conversion applications. The nanoparticles exhibited illumination-dependent photo-response, with enhanced photocurrent and low trap density indicating potential for light-driven functionalities. Additionally, this study demonstrates the integration of SnS nanoparticles into flexible PVA/PU sponge-based pressure sensor, achieving a sensitivity of 13.105 kPa⁻¹ over a 3.92–13.7 kPa pressure range. This dual functionality combining photodetection with sensitive pressure sensing application makes SnS nanoparticles as a versatile material for next-generation optoelectronic and wearable sensor technologies.