量子电子学报, 2019, 36 (1): 116, 网络出版: 2019-04-03
Al掺杂TiO2基晶体材料电子结构及光学性质的理论研究
Theoretical research of electronic structure and optical properties of Al-doped TiO2 crystalline materials
摘要
采用密度泛函理论计算分析的方法系统研究了Al掺杂TiO2基晶体材料的电子结构和光学性质.结果表明,本征TiO2材料具有直接带隙型能带,其带隙宽度为2.438 eV,Al掺杂TiO2材料同样具有直接带隙型能带,其带隙宽度降低至2.329 eV.本征TiO2与Al掺杂的TiO2材料均含有五个子能带,但是Al掺杂TiO2 材料子能带位置发生改变.Al掺杂在TiO2材料价带中引入大量新的能级,降低了费米能级上的态密度,Al掺杂为n型掺杂.对于Al掺杂TiO2材料来说, s态电子和p态电子主要在Al 掺杂TiO2 材料的带内跃迁过程起较大的作用.Al掺杂的TiO2材料最强的介电吸收峰在320 nm附近,Al掺杂拓展了TiO2材料的光吸收范围,其介电吸收能量范围向长波方向移动.本征TiO2及Al掺杂TiO2材料在1000 nm 以下波长的折射率曲线相似.Al掺杂TiO2材料在500 nm以下的折射率较本征TiO2材料降低,而500 nm 以上折射率较本征TiO2 材料增大.
Abstract
The electronic structure and optical properties of the Al-doped TiO2 crystalline material is investigated by density functional theory calculation method. The results show that the intrinsic TiO2 has direct energy gap of 2.438 eV, the Al-doped TiO2 has decreased direct energy gap of 2.329 eV. The intrinsic TiO2 and the Al-doped TiO2 both have five sub-bands, but the regions that the sub-band location has changed for the Al-doped TiO2. The Al has introduced many new bands within the valance bands; the density of states at Fermi level has been also decreased. The Al-doping is n type doping for the TiO2 material. The s and p electrons contribute to the mobility of carriers within the bands. The dielectric absorption peak of Al-doped TiO2 locates at 320 nm, the absorption region is widened by Al-doping and the absorption region has moved to long wave light area. Both systems have the similar refractive index curves under 1000 nm. The refractive index of Al-doped TiO2 is decreased under 500 nm, and it is increased above 500 nm comparing with the intrinsic TiO2.
唐文翰, 房慧, 李凡生, 黄灿胜, 余小英, 郑鑫, 王如志. Al掺杂TiO2基晶体材料电子结构及光学性质的理论研究[J]. 量子电子学报, 2019, 36(1): 116. TANG Wen-han, FANG Hui, LI Fan-sheng, HUANG Can-Sheng, YU Xiao-ying, ZHENG Xin, WANG Ru-zhi. Theoretical research of electronic structure and optical properties of Al-doped TiO2 crystalline materials[J]. Chinese Journal of Quantum Electronics, 2019, 36(1): 116.