Ramification of Li-ion array on structural, optical and electrical properties of vanadium pentoxide for energy-efficient material

The Li-ion doping in V₂O₅ leads to structural distortion, which results in modifications to the optical and electrical properties of the material. The X-ray diffractometer (XRD) measurement reveals orthorhombic and monoclinic structures for the present system. There is a significant change in the optical energy band which decreases from 3.37 eV to 2.44 eV, evaluated from Tauc extrapolation. The relation between energy band gap and refractive index is derived using different theoretical fitting formulas. The Reflectivity, reflection loss, and transmission coefficient values gradually decrease as Li-ion content increases. The molar refractive index (R_m) and molar electronic polarizability (α_e) decrease from 29.99 cm³/mol to 28.54 cm³/mol and 11.893ų to 11.318ų, respectively. The complex impedance and modulus spectra evaluate the electrical and dielectric properties of the vanadium pentoxide. The equivalent circuits have been analyzed for the complex dielectric parameters using Cole-Cole plots, and the electrical modulus shows the non-Debye type relaxation process. The analysis demonstrates the vital role of these materials in future electrochromic smart window devices (EC-SM) and optoelectronic applications.