Effect of CsBr on the optical properties and electrical conductivity of PVP/PVA composite for flexible optoelectronic devices

Abstract

This research contributes to the field by investigating the novel combination of PVP/PVA with CsBr NPs and elucidating the structural, optical, and electrical modifications that result from this combination, particularly focusing on the potential for energy storage and semiconductor characteristics of CsBr NPs. The insertion of CsBr NPs as a nanofiller has increased the degree of amorphousness in the PVP/PVA mixture, according to the XRD of the samples under investigation. The degree of crystallinity reduced from 32.15 to 18.56. FT-IR confirms the interaction or complexation of CsBr NPs with polymer blend. AFM investigations have revealed modifications in the surface morphology of the prepared films from smooth to rough as a result of the CsBr nanofiller. Utilizing UV/vis absorption spectra, the values of direct and indirect band gaps were determined. The optical band gaps decreased as CsBr NPs concentration increased, reaching a maximum of 3.65 eV for permitted indirect transition. By Jonscher's universal power equation, composites have a higher AC conductivity at high frequencies. It is also found to rise with increasing nanoparticle concentration. The film containing 15 wt% CsBr NP exhibits good optical properties, good conductivity, and a high dielectric constant. Dielectric constants (ε′ and ε′′) improved with increasing CsBr NPs concentration and decreased with rising frequency. The polymer nanocomposite acquired met the essential optical and electrical criteria, indicating its suitability for various electronic applications. These applications encompass functions such as energy storage devices, gas sensors, and optoelectronic devices.