标题：First-principles GGA+U study of the different conducting properties in pentavalent-ion-doped anatase and rutile TiO2
作者：Yang, Kesong ;Dai, Ying ;Huang, Baibiao ;Feng, Yuan Ping
作者机构：[Yang, Kesong ;Dai, Ying ;Huang, Baibiao ] School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China;[Yan 更多
来源：Journal of Physics D: Applied Physics
摘要：The electronic properties of pentavalent-ion (Nb5+, Ta5+, and I5+) doped anatase and rutile TiO2are studied using spin-polarized GGA+U calculations. Our calculated results indicate that these two phases of TiO2exhibit different conductive behavior upon doping. For doped anatase TiO2, some up-spin-polarized Ti 3d states lie near the conduction band bottom and cross the Fermi level, showing an n-type half-metallic character. For doped rutile TiO2, the Fermi level is pinned between two up-spin-polarized Ti 3d gap states, showing an insulating character. In addition to the Nb (Ta)-doped anatase TiO2, we propose that the I-doped anatase TiO2can also be a potential transparent conducting oxide, which is worthy of further experimental verification. These findings clarify the long-standing controversy of whether GGA+U calculation can successfully predict the conducting property in the Nb (Ta)-doped anatase phase and the insulating property in the rutile phase. Moreover, our results show that the symmetry breaking can cause a metal-insulating transition in pentavalent-ion-doped anatase TiO2, though this symmetry breaking may not occur spontaneously because of the relatively high energy barrier. © 2014 IOP Publishing Ltd.