THE STRUCTURAL AND OPTICAL CHARACTERISTICS OF POLYVINYLPYRROLIDONE DOPED WITH NANO CRYSTAL NAF FILMS

The samples of polyvinypolypiroddone were doped with nanostructure NaF by using different preparations such as a wet casting, quartz cell and spin - coating techniques with concentrations (0,2,4,6,8,10,12,14wt%). The X ? Ray diffraction of the samples indicate that the pure PVP are amorphous structure and the doped are polycrystalline for selective concentrations (4, 8, 12, 14) wt% with nano crystal grain size (30.10, 26.00, 22.88,31.79) nm respectively. It was observed that the amorphaousation decreases with increasing NaF concentration. The Fourier Transform Infrared (FTIR) spectrometer measurements show that the stretching vibration in the oxygen containing chain polymer with change the covalent bond distribution with fluoride ion bonds that is the greatest. Increasing UV-vis absorption spectrometer refers to a maximum peak absorbance spectra of different techniques have about (0.5-0.6) values, and there are a high shifting in a casting method. The indirect Egopt of pure and doped PVP films were estimated to be decrease about (3.65, 3.57, 3.55, 3.45, 3.33), and 3.25 eV for indirect allowed transitions, whereas the indirect forbidden band gaps were determined as (3.52, 3.50, 3.41, 3.31, 3.18) and 3.13 eV with increase sodium fluoride contents respectively. All prepared samples appeared near band edge peak absorption at about (300nm) of different deposition, it close to each other for bulk specimens (solution), shifting at higher frequencies.