کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5376316 | 1504319 | 2007 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Surface studies of nitrogen implanted TiO2
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Rutile TiO2(1Â 1Â 0) single crystals have been doped by nitrogen-ion implantation. The change in the valence band and in the core level peak shapes are characterized by photoemission spectroscopy. Surface morphologies are characterized by scanning tunneling microscopy. N-dopants are observed to be in a 3â charge state and to substitute for O-anions in the TiO2 lattice for N-concentrations up to â¼5% of the anions. The higher valency of the N-dopants compared to the host O-anions is proposed to be compensated by the formation of O-vacancies and/or Ti-interstitials. Two chemically shifted components arise in the Ti-2p core level upon N-doping. These components, shifted by 0.9Â eV and 2.1Â eV, are assigned to Ti-bound to N-ligands and possibly due to O-vacancies in the lattice. The Ti-3d band gap state observed in UPS is initially suppressed upon room temperature N-implantation and recovers a similar intensity as for undoped TiO2 samples upon annealing. This indicates that electrons left behind upon creation of O-vacancies are filling the N-2p level rather than Ti-3d states. The filled N-2p state is found at the top of the TiO2 valence band and is believed to be responsible for the band gap narrowing of N-doped TiO2 that shifts the photoactivity of TiO2 into the visible spectrum.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Physics - Volume 339, Issues 1â3, 15 October 2007, Pages 36-43
Journal: Chemical Physics - Volume 339, Issues 1â3, 15 October 2007, Pages 36-43
نویسندگان
Matthias Batzill, Erie H. Morales, Ulrike Diebold,