C掺杂锐钛矿相TiO2吸收光谱的第一性原理研究

运用第一性原理，对C掺杂锐钛矿相TiO₂的电子结构进行了研究，从能带结构理论解释了C掺杂TiO₂吸收光谱的一些实验现象.发现在C掺杂后的锐钛矿相TiO₂的禁带宽度增大，并且在带隙中出现了杂质能级，这些杂质能级主要是由C 2p轨道上的电子构成的，它们之间是独立的,正是这些独立的杂质能级使TiO₂掺杂后可以发生可见光响应.价带上的电子可以吸收一定能量的光子跃迁到杂质能级，而杂质能级上的电子也可以吸收一定能量的光子跃迁到导带，所以从理论上可以计算出掺杂后的TiO₂在可见光范围内存在两个吸收边，与实验中所得到的现象相一致. 关键词： C掺杂 2')" href="#">锐钛矿TiO₂ 能带结构 吸收光谱

The first-principles study of absorption spectrum of C-doped anatase TiO_2

We have performed first-principle calculations of electronic band structure of C-doped anatase TiO2,and explained some experimental phenormena of C-doped TiO2's absorption spectrum.The results indicated that the band gap broaders and some new bands appears in the band gap.These new bands result from C 2p orbitals,they are separated,and their existance explains the visible light response.The electrons in the valence band can be excited to the new states and subsequently excited to the conduction band,leading...