Dopant location identification in Nd{sup 3+}-doped TiO{sub 2} nanoparticles
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716 (United States)
Large band gap semiconductors are typically doped in order to enhance their photocatalytic, photovoltaic, and other chemical and optoelectronic properties. The identification of dopant position and its local environment are essential to explore the effect of doping. X ray techniques, including extended x ray absorption fine structure, x ray photoelectron spectroscopy, and x ray diffraction, were performed to analyze the Nd (0 to 1.5 at. %) dopant location and the structural changes associated with the doping in anatase TiO{sub 2} nanoparticles, which were synthesized by metalorganic chemical vapor deposition. Nd ions were determined to have a trivalent chemical state and substitute for Ti{sup 4+} in the TiO{sub 2} structure. The substitutional Nd{sup 3+} ions cause anatase lattice expansion along c direction with a maximum value of 0.15 A at 1.5 % Nd doping level and the local structure of the dopants changes towards rutile like configuration. The lengths of the nearest neighbor Nd-O and Nd-Ti bonds increase by 0.5-0.8 A compared to their counterparts in the pure TiO{sub 2} host structure. The substitutional nature of Nd{sup 3+} dopants explains why they are efficient not only for charge carrier separation but also for visible light absorption in TiO{sub 2}.
- OSTI ID:
- 20719632
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 72, Issue 15; Other Information: DOI: 10.1103/PhysRevB.72.155315; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
CHARGE CARRIERS
CHEMICAL BONDS
CHEMICAL STATE
CHEMICAL VAPOR DEPOSITION
DOPED MATERIALS
FINE STRUCTURE
NANOSTRUCTURES
NEODYMIUM ADDITIONS
NEODYMIUM IONS
RUTILE
SEMICONDUCTOR MATERIALS
TITANIUM IONS
TITANIUM OXIDES
X RADIATION
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
X-RAY SPECTRA