Tailoring the Structural, Optical, and Electrical Performance of PVA Through Sn_0.8Mn_0.2S Nanostructures Incorporation...

This work aims to produce a new nanocomposite of Sn_0.8Mn_0.2S nanostructures incorporated into polyvinyl alcohol (PVA) for optoelectronic applications. Sn_0.8Mn_0.2S/PVA nanocomposite was prepared by combining a precipitation-based synthesis of Sn_0.8Mn_0.2S with the solution casting of the PVA matrix. FTIR spectroscopy was used to examine the chemical interactions and bonding between the Sn_0.8Mn_0.2S nanostructures and PVA chains. Morphological properties were investigated by the SEM technique. The X-ray diffraction technique was used to study the structural properties. UV-Visible spectroscopy was applied to explore the optical properties. Optical analysis shows that the direct and indirect optical bandgap decreased from 5.36 and 4.95 eV for the plain PVA to 1.94 and 1.32 eV at the highest loading (10 wt.%), accompanied by an increase in the refractive index from 1.69 to 2.33. Both the dielectric constants and optical conductivity of PVA likewise enhanced markedly with an increasing Sn_0.8Mn_0.2S amount. Four-probe DC measurements performed across 300 to 400 K demonstrated a reduction in PVA resistivity together with a drop in the activation energy, from 0.39 eV down to 0.18 eV, as the loading increased up to 1.0 wt.%, identifying this concentration as the most favorable for electrical performance. These findings recommend Sn_0.8Mn_0.2S nanostructures as an effective means of engineering the structural, optical, and electrical characteristics of PVA, with a clear relevance to optoelectronic device applications.