Optical properties of thin films of mixed Ni–W oxide made by reactive DCmagnetron sputtering
2011 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 519, no 9, 2914-2918 p.Article in journal (Refereed) Published
Thin films of NixW1−x oxides with x=0.05, 0.19, 0.43 and 0.90 were studied. Films with thicknesses in the range 125–250 nm were deposited on silicon wafers at room temperature by reactive DC magnetron co-sputtering from targets of Ni and W. The films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectroscopic ellipsometry (SE). XRD spectra and SEMmicrographs showed that all films were amorphous and possessed a columnar structure. The ellipsometric angles Ψ and Δ of as-deposited films were measured by a rotating analyzer ellipsometer in the UV–visible-near infrared range (0.63–6.18 eV) and by an infrared Fourier transform rotating compensator ellipsometer in the 500–5200 cm−1 wavenumber range. SE measurementswere performed at angles of incidence of from50 ° to 70 °. Parametricmodelswere used to extract thicknesses of the thin films and overlayers of NixW1−x oxide at different compositions, band gaps and optical constants. Features in the optical spectra of the NixW1−x oxideswere compared with previous data on tungsten oxide, nickel oxide and nickel tungstate.
Place, publisher, year, edition, pages
2011. Vol. 519, no 9, 2914-2918 p.
IdentifiersURN: urn:nbn:se:uu:diva-178579DOI: 10.1016/j.tsf.2010.11.089OAI: oai:DiVA.org:uu-178579DiVA: diva2:542358