Mechanism for Lower Resistivity of Niobium-Doped Anatase Titanium Dioxide Obtained in Oxygen-Reduced Atmosphere: Investigation by Generalized Gradient Approximation +U Method

作者：Orita Nozomi^*

来源：Japanese Journal of Applied Physics, 2011, 50(4): 041102.

DOI：10.1143/JJAP.50.041102

I investigated the mechanism by which the resistivity of niobium (Nb)-doped anatase titanium dioxide (TiO2) grown in an oxygen-reduced atmosphere decreases. For this purpose, I performed the generalized gradient approximation (GGA)+U calculation for the several oxygen-related defects in a Nb-doped TiO2 (TNO) supercell: an interstitial oxygen (O-int) atom in TNO, an O-int atom and an oxygen vacancy (V-O) in TNO, and a V-O in TNO. The obtained results showed that the O-int atoms trap the doped electrons and that the electrons are restored to the conduction bands by removing the O-int atoms. Therefore, removing the O-int atoms in oxygen-reduced atmosphere causes the lower resistivity. The defect formation enthalpies also indicated that the structure without the O-int atoms is stable in oxygen-reduced atmosphere.

• 出版日期2011-4