Li掺杂α-Bi_(2)O_(3)电子结构和光电性质的 第一性原理研究  

First-Principles Study on Electronic Structure and Photoelectric Properties of Li-Dopedα-Bi_(2)O_(3)

作　　者：马一涵 张文清 陈长鹏[1,2] 杨蕾 MA Yihan;ZHANG Wenqing;CHEN Changpeng;YANG Lei(School of Science,Wuhan University of Technology,Wuhan 430070,China;Research Center of Materials Genome Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学理学院,湖北武汉430070 [2]武汉理工大学材料基因工程中心,湖北武汉430070

出　　处：《中北大学学报（自然科学版）》2023年第5期503-509,共7页Journal of North University of China(Natural Science Edition)

基　　金：国家大学生创新创业训练项目(S202110497146)。

摘　　要：α-Bi_(2)O_(3)是一种新型光催化材料,则改善α-Bi_(2)O_(3)在可见光范围内的光吸收率,对其在污水处理和环境治理方面的应用具有重要意义。本文采用第一性原理密度泛函理论对Li掺杂α-Bi_(2)O_(3)的晶体结构、电子结构、光学性质进行了计算研究。结果表明,Li掺杂α-Bi_(2)O_(3)的体系结构较为稳定,有较小的结构变形。本征α-Bi_(2)O_(3)是带隙值为2.85eV的间接带隙半导体,Li掺杂后由于Li 2s态电子的影响,促使价带能级杂化,体系禁带宽度减小为1.131 eV,导带下方出现了杂质能级,便于电子跃迁,降低氧化还原反应所需光子能量,提高光催化效率。Li掺杂使α-Bi_(2)O_(3)对可见光的吸收范围由400.00nm~478.76nm延伸至400.00nm~800.00nm,拓宽了α-Bi_(2)O_(3)的可见光吸收范围,吸收边界发生红移。研究结果阐明了Li掺杂α-Bi_(2)O_(3)光催化性能得到提高的理论原因,为Li掺杂α-Bi_(2)O_(3)在光催化领域中的应用提供了理论基础。α-Bi_(2)O_(3) is investigated as a new photocatalytic material,which can improve the light absorption rate ofα-Bi_(2)O_(3)in the visible light range.It is of great significance for its application in sewage treatment and environmental treatment.In this paper,the crystal structure,electronic structure and optical properties of Li doped α-Bi_(2)O_(3)were calculated and studied by using the first-principles density functional theory.The results indicated that the structure of Li dopedα-Bi_(2)O_(3) system was stable and had a small structural deformation.The intrinsicα-Bi_(2)O_(3)was an indirect band map semiconductor material with a band gap of 2.85 eV.After Li doping,due to the major contribution of 2 s state electrons of Li,the valence band level hybridization was promoted,and the band gap width of the system was reduced to 1.131 eV.An impurity level appeared below the conduction band,which facilitated electron transition,reduced the photon energy required for redox reactions and improved the photocatalytic efficiency.The visible light absorption range ofα-Bi_(2)O_(3)was extended from 400.00 nm-478.76 nm to 400.00 nm-800.00 nm by Li doping,which extended the absorption range of visible light ofα-Bi_(2)O_(3),and the absorption boundary was red shifted.The results clarify the theoretical reasons for the improvement of Li dopedα-Bi_(2)O_(3) photocatalytic performance,and provide a theoretical basis for the application of Li dopedα-Bi_(2)O_(3)in the field of photocatalysis.

关 键 词：Li掺杂 α-Bi_(2)O_(3) 第一性原理 电子结构 光学性质 晶体结构 

分 类 号：O472[理学—半导体物理] TQ135.3[理学—物理]