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Title:Band gap engineering of (N, Si)-codoped TiO2 from hybrid density functional theory calculations
Authors:Run Long, Niall J. English, 2012
Abstract: We have investigated systematically the influence on electronic properties of anatase-TiO2 of codoping by N and Si at different concentrations using Heyd–Scuseria–Ernzerhof (HSE06) hybrid density functional theory calculations. The optimized total energy shows that TiO2 codoping by N and Si favours a configuration of two substitutional N atoms located at two adjacent O sites, with one substitutional Si atom at their neighbouring Ti site. We show that N–Si codoping can harvest longer-wavelength visible-light than either those of N and Si monodoping, owing to the contribution from N 2p in the 'forbidden gap' and Si 3s–3p at the tail of the conduction band. Increasing the N doping concentration leads to a larger extent of gap narrowing, which is directly related to coupling between N atoms. Our results suggest that double-hole coupling plays a key role in similar systems to obtain high visible-light photoactivity in TiO2-based photocatalysts.
ICHEC Project:Simulation of photo-electronic excitation in titania nanofilms
Publication:New Journal of Physics 14 (5), 053007, May 2012
URL: http://dx.doi.org/10.1088/1367-2630/14/5/053007
Status: Published

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