Ag-Ce共掺杂锐钛矿型TiO_2的电子结构与光学性质  

Electronic Structure and Optical Property of Ag-Ce Co-Doped Anatase TiO_2

作　　者：曾凡菊[1] 谭永前[1] 余幼胜[1,2] 张颂[1] 韩伟超[1] 杨永亮[1] 

机构地区：[1]凯里学院物理与电子工程学院,贵州凯里556011 [2]南京大学物理学院,江苏南京210093

出　　处：《激光与光电子学进展》2017年第7期258-264,共7页Laser & Optoelectronics Progress

基　　金：贵州省科技厅;黔东南州科技局;凯里学院科技合作协议项目(黔科合LH字[2016]7318);贵州省普通高等学校创新人才团队项目(黔教合人才团队字[2012]06);凯里学院青年课题(Z1123)

摘　　要：利用Ag、Ce原子对锐钛矿相TiO_2进行了替位掺杂,构建了Ag、Ce单掺杂及Ag-Ce共掺杂的锐钛矿相TiO_2体系,并采用第一性原理计算研究了掺杂体系的电子结构及光学吸收特性。结果表明:Ag-Ce共掺杂后,Ag-4d和O-2p电子轨道的共同作用引入了有利于电子跃迁的浅杂质能级;Ag-4d和Ce-4f电子轨道的强相互作用使得禁带宽度减小,吸收光谱发生红移;Ce离子的引入有效地降低了杂质体系中电子-空穴对的复合速率,提高了体系的量子效率。因此,Ag-Ce共掺杂TiO_2既扩展了吸收光谱范围又提高了TiO_2的量子效率,使TiO_2的光催化性能得到了提高。The Ag-doped TiO2, Ce-doped TiOe and Ag-Ce co doped anatase TiO2 systems are built by the substitution doping of Ag and Ce atoms at the anatase TiO2. The electronic structures and optical absorption properties of the doped systems are investigated with the first principle. The results show that, as for the Ag-Ce co- doped anatase TiO2, a shallow impurity energy level conducive to electronic transition is introduced with the synergy of Ag-4d and O-2p electron orbits; its forbidden bandgap is reduced because of the strong synergy of Ag-4d and Ce- 4f electronic orbits, which results in the red shifts of the absorption spectra; the introduction of Ce ions effectively reduces the recombination rate of electron-hole pairs in the impurity system, which improves the quantum efficiency of the system. Therefore, the Ag-Ce co-doped anatase TiO2 not only extends the range of the absorption spectra but also increases the quantum efficiency of TiO2, and the photoeatalytic property of TiO2 is improved.

关 键 词：材料 Ag—Ce共掺杂TiO2 第一性原理 电子结构 光学性质 

分 类 号：O472.3[理学—半导体物理]