Optical and electrical properties of SnBr₂-doped polyvinyl alcohol (PVA) polymeric solid electrolyte for electronic and optoelectronic applications

A polymer electrolyte of PVA (Polyvinyl alcohol) doped with Tin (II) Bromide (SnBr₂) at different weight ratios was synthesized by casting technique. The structure analysis of the composites was displayed by XRD (X-ray diffraction) and F.T. (Fourier transform)-IR techniques, which showed the decrement in the crystallinity with the argument of SnBr₂ concentration and functional interaction between SnBr₂ and PVA, respectively. The absorbance (Abs.) and transmittance (T%) in the range of wavelength 190−2500 nm were documented through the UV–vis spectrophotometer to research the influence of SnBr₂ on the optical performance of PVA. The incorporation between SnBr₂ and the main chain of the PVA matrix brings out a notable change in the optical properties of the polymer electrolytes. The optical band gap, refractive index (n), extinction coefficient (k), the real and imaginary parts of dielectric constant (ε_r and ε_i) as well as optical conductivity (σ_op) exposed a clear dependence on the SnBr₂ content. Moreover, the dependence of dielectric properties on the contents of SnBr₂ has been studied in the range of frequency from 100 Hz to 1 MHz. The conduction mechanism is mainly correlated Barrier Hopping (CBH) model. SnBr₂/(PVA) polymeric solid electrolyte can be used for electronic and optoelectronic and electrochemical devices.