A hybrid density functional study on the electron and hole trap states in anatase titanium dioxide

We present a theoretical study on electron and hole trap states in the bulk and (001) surface of anatase titanium dioxide using screened hybrid density functional calculations. In both the bulk and surface, calculations suggest that the neutral and ionized oxygen vacancies are possible electron trap...

Full description

Saved in:
Bibliographic Details
Published in:Physical chemistry chemical physics : PCCP 2012-01, Vol.14 (2), p.589-598
Main Authors: Yamamoto, Takenori, Ohno, Takahisa
Format: Article
Language:English
Subjects:
Anatase
Chemistry
Colloidal state and disperse state
Density
Electron traps
Exact sciences and technology
General and physical chemistry
Hole traps
Mathematical analysis
Physical and chemical studies. Granulometry. Electrokinetic phenomena
Surface chemistry
Titanium dioxide
Vacancies
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present a theoretical study on electron and hole trap states in the bulk and (001) surface of anatase titanium dioxide using screened hybrid density functional calculations. In both the bulk and surface, calculations suggest that the neutral and ionized oxygen vacancies are possible electron traps. The doubly ionized oxygen vacancy is the most stable in the bulk, and is a candidate for a shallow donor in colorless anatase crystals. The hole trap states are localized at oxygen anions in both the bulk and surface. The self-trapped electron centered at a titanium cation cannot be produced in the bulk, but can be formed at the surface. The electron trap level at the surface oxygen vacancy is consistent with observations by photoelectron spectroscopy. The optical absorptions and luminescence in UV-irradiated anatase nanoparticles are found to come from the surface self-trapped hole and the surface oxygen vacancy. Electron and hole trap states in the bulk and surface of anatase TiO 2 , and the optical processes due to them.
ISSN:1463-9076
1463-9084
DOI:10.1039/c1cp21547g