Optical and Conductivity Studies of Cr3+ Doped Polyvinyl Pyrrolidone Polymer Electrolytes

AbstractPolymer electrolyte films of polyvinyl pyrrolidone (PVP) embedded with various concentrations of Cr3+ ions were prepared by a solution casting technique. The complexation between the Cr3+ ions and the polymer was confirmed by Fourier transform infrared (FTIR) spectroscopy and UV–vis spectroscopy. The electrical conductivity of the films was measured using an impedence analyzer in the frequency range of 42 Hz to 5 MHz at ambient temperature. It was observed that the conductivity increased with the increase in the Cr3+ ion concentration. UV–visible absorption spectra in the wavelength range of 200–800 nm were used to determine the direct and indirect optical energy band gaps and optical absorption edge. Both of the optical band gaps decreased with the increase in Cr3+ ion concentration. FTIR studies on pure and Cr3+ doped PVP polymer films revealed the vibrational changes that occurred due to the effect of the dopant Cr3+ ions in the polymer. Our results suggested that Cr3+, as a dopant, is a good choice to improve the electrical properties of PVP polymer electrolytes.