Ellipsometric Studies on Silver Telluride Thin Films

Silver telluride thin films of thickness between 45 nm and 145 nm were thermally evaporated on well cleaned glass substrates at high vacuum better than 10 – 5 mbar. Silver telluride thin films are polycrystalline with monoclinic structure was confirmed by X-ray diffractogram studies. AFM and SEM images of these films are also recorded. The phase ratio and amplitude ratio of these films were recorded in the wavelength range between 300 nm and 700 nm using spectroscopic ellipsometry and analysed to determine its optical band gap, refractive index, extinction coefficient, and dielectric functions. High absorption coefficient determined from the analysis of recorded spectra indicates the presence of direct band transition. The optical band gap of silver telluride thin films is thickness dependent and proportional to square of reciprocal of thickness. The dependence of optical band gap of silver telluride thin films on film thickness has been explained through quantum size effect. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2371

SPECTROSCOPIC STUDIES ON SILVER SELENIDE THIN FILMS

Silver selenide thin films of thickness between 80 nm and 160 nm were prepared by thermal evaporation technique at a high vacuum better than 2x10 -5 mbar on well cleaned glass substrates at a deposition rate of 0.2 nm/sec. Silver selenide thin films were polycrystalline with orthorhombic structure. Ellipsometric spectra of silver selenide thin films have been recorded in the wavelength range between 300 nm and 700 nm. Optical constants like refractive index, extinction coefficient, absorption coefficient, and optical band gap of silver selenide thin film have been calculated from the recorded spectra. The refractive index of silver selenide has been found to vary between 1.9 and 3.2 and the extinction coefficient varies from 0.5 to 1.6 with respect to their corresponding thickness of the films. Transmittance spectra of these films have been recorded in the wavelength range between 300 nm and 900 nm and its spectral data are analysed. The photoluminescence studies have been carried out on silver selenide thin films and the strong emission peak is found around 1.7 eV. The calculated optical band of thermally evaporated silver selenide thin films is found to be around 1.7 eV from their Ellipsometric, UV-Visible and Photoluminescence spectroscopic studies

Spectroscopic Studies on Silver Selenide Thin Films

Silver selenide thin films of thickness between 80 nm and 160 nm were prepared by thermal evaporation technique at a high vacuum better than 2x10(-5)mbar on well cleaned glass substrates at a deposition rate of 0.2 nm/sec. Silver selenide thin films were polycrystalline with orthorhombic structure. Ellipsometric spectra of silver selenide thin films have been recorded in the wavelength range between 300 nm and 700 nm. Optical constants like refractive index, extinction coefficient, absorption coefficient, and optical band gap of silver selenide thin film have been calculated from the recorded spectra. The refractive index of silver selenide has been found to vary between 1.9 and 3.2 and the extinction coefficient varies from 0.5 to 1.6 with respect to their corresponding thickness of the films. Transmittance spectra of these films have been recorded in the wavelength range between 300 nm and 900 nm and its spectral data are analysed. The photoluminescence studies have been carried out on silver selenide thin films and the strong emission peak is found around 1.7 eV. The calculated optical band of thermally evaporated silver selenide thin films is found to be around 1.7 eV from their Ellipsometric, UV-Visible and Photoluminescence spectroscopic studies

A study on methylene blue degradation: enhanced photocatalytic activity of Ag-ZnO nanocomposities

Silver/Zinc Oxide nanocomposites (Ag-ZnO NCs) were fabricated by varying the weight percentages of both Ag and ZnO for investigating its photocatalytic activity. The structural, morphology and optical response of the prepared nanocomposites were examined with PXRD, FESEM, TEM, EDAX, XPS, FT-IR, UV–vis-DRS and PL spectroscopy. The effect of Ag and ZnO concentrations on these nanocomposites was examinedby analyzing thephotocatalytic activity towards Methylene Blue (MB) dye degradationunder the UV irradiation. The overall results suggested that, AZ _1:1 NC achieved better photocatalytic activity than AZ _1:2 and AZ _2:1 composition. Therefore, the present study demonstrated the viability of the Ag-ZnO NCs in remediation of environmental pollutant and treatment of waste water