Synthesis and characterization of PVA capped SnSe for IR sensor and piezo-resistive sensor applications

The study presents an investigation of PVA capped SnSe properties and their prospective application in various sensor technologies. The PVA capped SnSe was analyzed by various analytical technique such as scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). Tiny particles of SnSe were closely bond to each other with the help of PVA, revealed from SEM analysis. The atomic (%) of SnSe was found to be stoichiometric and the additional chemical elements: C and O were also observed due to PVA. The value of average crystallite size and lattice strain of orthorhombic PVA capped SnSe were obtained to be 22 nm and 1.66 × 10⁻³ respectively from XRD spectra. The temperature-dependent electrical characterization of synthesized material was examined. In infra-red (IR) sensors, the negative and positive photoconductivity effect were observed for zero biased and biased condition respectively. The thermal sensitivity and photo-response parameters of PVA capped SnSe were determined for various biased condition. Additionally, for different pressure (10 kPa to 50 kPa) and finger tapping speed condition, a novel application in piezo-resistive pressure sensor was explored by incorporating PVA capped SnSe into a PU composite.