Influence of doping on the photoactive properties of magnetron-sputtered titania coatings: Experimental and theoretical study
|Title:||Influence of doping on the photoactive properties of magnetron-sputtered titania coatings: Experimental and theoretical study||Authors:||McDonnell, Kevin
English, Niall J.
|Permanent link:||http://hdl.handle.net/10197/4676||Date:||Sep-2012||Abstract:||Titanium dioxide (TiO2) thin films, doped with chromium (Cr) and codoped with chromium-carbon (Cr, C) and chromium-nitrogen (Cr, N) of various concentrations, were deposited using magnetron sputtering. Postdeposition thermal treatments were carried out at 450 ◦C for 5 h to change the as-deposited amorphous coatings to their crystalline form. The crystalline phase was found to be dependent on the amount and type of dopant present. Ultraviolet-visible (UV-Vis) absorption data and band gap energies calculated by spectroscopic ellipsometry showed that, on increasing Cr concentration, a shift of the absorption edge towards visible light and a reduction of the band gap occurred. This was further improved by codoping of Cr with either N or C, with the latter case exhibiting more photo-activity towards visible light. In addition, hybrid density functional theory (DFT) calculations were performed for Cr-, N-. and C-monodoping, together with Cr-C and Cr-N codoping, in both rutile and anatase phases of crystalline titania. Using this method, absorption coefficients and band gaps were determined to explore photo-activity. Very good, semiquantitative agreement was found between the DFT and experimental approaches for these quantities, underlining the key role of state-of-the-art quantum calculations in interpreting and guiding experimental studies of doping in metal oxides.||Type of material:||Journal Article||Publisher:||American Physical Society||Copyright (published version):||2012 American Physical Society||Keywords:||Doping;Photoactive properties||DOI:||10.1103/PhysRevB.86.115306||Language:||en||Status of Item:||Peer reviewed|
|Appears in Collections:||Mechanical & Materials Engineering Research Collection|
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