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Title: The electronic structure changes and the origin of the enhanced optical properties in N-doped anatase TiO{sub 2}—A theoretical revisit

Abstract

We have investigated the electronic structure changes and the origin of the enhanced optical properties of N-doped anatase TiO{sub 2} using first-principles density-functional theory calculations. To determine the band gap variations induced by N-doping, we developed a new approach to locate the effective valence band maximum (VBM) by characterizing the degree of localization of the N-induced states in the band structures of various N-doped TiO{sub 2} systems. Our calculations show that the band gap variations are largely affected by the local bonding structures and doping concentration of the substitutional N atoms. As the N content is up to certain level, some local bonding structures can indeed cause band gap reduction due to the formation of band-like delocalized states above the VBM of TiO{sub 2}, while other local bonding configurations may simply form localized impurity states in the band gap. Accordingly, the N-induced localized and delocalized electronic states can exist simultaneously to contribute to the enhanced optical properties of anatase TiO{sub 2}. Our computational approach also provides a new way to investigate the band gap engineering of other wide band gap semiconductor material systems.

Authors:
; ;  [1]
  1. Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)
Publication Date:
OSTI Identifier:
22314392
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 116; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CONCENTRATION RATIO; DENSITY FUNCTIONAL METHOD; DOPED MATERIALS; ELECTRONIC STRUCTURE; OPTICAL PROPERTIES; ORIGIN; SEMICONDUCTOR MATERIALS; TITANIUM OXIDES

Citation Formats

Kuo, Chin-Lung, Chen, Wei-Guang, and Chen, Tzu-Ying. The electronic structure changes and the origin of the enhanced optical properties in N-doped anatase TiO{sub 2}—A theoretical revisit. United States: N. p., 2014. Web. doi:10.1063/1.4894444.
Kuo, Chin-Lung, Chen, Wei-Guang, & Chen, Tzu-Ying. The electronic structure changes and the origin of the enhanced optical properties in N-doped anatase TiO{sub 2}—A theoretical revisit. United States. https://doi.org/10.1063/1.4894444
Kuo, Chin-Lung, Chen, Wei-Guang, and Chen, Tzu-Ying. 2014. "The electronic structure changes and the origin of the enhanced optical properties in N-doped anatase TiO{sub 2}—A theoretical revisit". United States. https://doi.org/10.1063/1.4894444.
@article{osti_22314392,
title = {The electronic structure changes and the origin of the enhanced optical properties in N-doped anatase TiO{sub 2}—A theoretical revisit},
author = {Kuo, Chin-Lung and Chen, Wei-Guang and Chen, Tzu-Ying},
abstractNote = {We have investigated the electronic structure changes and the origin of the enhanced optical properties of N-doped anatase TiO{sub 2} using first-principles density-functional theory calculations. To determine the band gap variations induced by N-doping, we developed a new approach to locate the effective valence band maximum (VBM) by characterizing the degree of localization of the N-induced states in the band structures of various N-doped TiO{sub 2} systems. Our calculations show that the band gap variations are largely affected by the local bonding structures and doping concentration of the substitutional N atoms. As the N content is up to certain level, some local bonding structures can indeed cause band gap reduction due to the formation of band-like delocalized states above the VBM of TiO{sub 2}, while other local bonding configurations may simply form localized impurity states in the band gap. Accordingly, the N-induced localized and delocalized electronic states can exist simultaneously to contribute to the enhanced optical properties of anatase TiO{sub 2}. Our computational approach also provides a new way to investigate the band gap engineering of other wide band gap semiconductor material systems.},
doi = {10.1063/1.4894444},
url = {https://www.osti.gov/biblio/22314392}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 9,
volume = 116,
place = {United States},
year = {Sun Sep 07 00:00:00 EDT 2014},
month = {Sun Sep 07 00:00:00 EDT 2014}
}