Optical Dielectric Loss as a Novel Approach to Specify the Types of Electron Transition: XRD and UV-vis as a Non-Destructive Techniques for Structural and Optical Characterization of PEO Based Nanocomposites

摘要

The structure and optical properties of polyethylene oxide (PEO) doped with tin titanate (SnTiO ) nano-filler were studied by X-ray diffraction (XRD) and UV-Vis spectroscopy as non-destructive techniques. PEO-based composed polymer electrolytes inserted with SnTiO nano-particles (NPs) were synthesized through the solution cast technique. The change from crystalline phase to amorphous phase of the host polymer was established by the lowering of the intensity and broadening of the crystalline peaks. The optical constants of PEO/SnTiO nano-composite (NC), such as, refractive index ( ), optical absorption coefficient ( ), dielectric loss ( ), as well as dielectric constant (ε ) were determined for pure PEO and PEO/SnTiO NC. From these findings, the value of of PEO altered from 2.13 to 2.47 upon the addition of 4 wt.% SnTiO NPs. The value of ε also increased from 4.5 to 6.3, with addition of 4 wt.% SnTiO . The fundamental optical absorption edge of the PEO shifted toward lower photon energy upon the addition of the SnTiO NPs, confirming a decrement in the optical band gap energy of PEO. The band gap shifted from 4.78 eV to 4.612 eV for PEO-doped with 4 wt.% SnTiO . The nature of electronic transitions in the pure and the composite material were studied on the basis of Tauc’s model, while optical examination was also carried out to calculate the optical band gap.