In_2O_3晶体电子结构和光吸收机理研究  

Study on the electronic structures and the optical absorption mechanism of In_2O_3 crystals

作　　者：刘检[1] 刘廷禹[1] 李海心[1] 刘凤明[1] 

机构地区：[1]上海理工大学理学院,上海200093

出　　处：《物理学报》2015年第19期67-72,共6页Acta Physica Sinica

基　　金：沪江基金(批准号:B14004)资助的课题~~

摘　　要：为了得到准确的In2O3晶体电子结构,本文分别采用GGA,GGA+U,HSE06的方法计算了电子结构,并进行了G0W0修正,通过比较计算结果,得到HSE06+G0W0方法计算得到的禁带宽带最接近实验结果.在此基础上使用Hedin的G0W0近似方法和Bethe-Salpeter方程计算得到了In2O3晶体的光学性质,计算结果与实验结果吻合很好,在此基础上通过对准粒子能带结构、光学跃迁矩阵和光学吸收谱的分析,给出了In2O3晶体的光学跃迁机理.Indium oxide with its wide gap is a multifunctional semiconductor material, which has gained application in many areas. Indium oxide films show high electrical property and high transparency, which have been applied in OLED display, flat-panel display, thin film solar cells, etc. However, the mechanisms of both high electrical and high transparent properties are still not clear up to now. So in this paper, the electronic structures of the In2O3 crystals are studied by GGA, GGA＋U, HSE06 and G0W0 corrections. The mechanisms of optical transition and formation of transparent electrode in In2O3 crystals are studied using Hedin’s G0W0 approximation and the Bethe-Salpeter equation. The complex refractive index, complex dielectric function and optical absorption spectrum of the In2O3 crystal have been obtained, which are in good agreement with experimental results. By analyzing the quasi-particle band structures, optical transition matrix and optical absorption spectrum, the mechanisms of optical transition and formation of transparent electrode in In2O3 can be interpreted. BSE （Bethe-Salpeter equation） calculation results show that the transition from Γ8 toΓ1 is permitted, however, the transition probability is far less than that from Γ10 to Γ1. This is because, for Γ8 to Γ1 transition, there are three even symmetry bands and two odd symmetry bands, in which only the transition from two odd symmetry bands to the conduction band is permitted. Other causes for this phenomenon are that in the In2O3 primitive cell there exist some overlapping bands, which result in the false transition. Therefore, this work argues that in the In2O3 crystals optical band gap is 4.167 eV, which corresponds to the direct transition fromΓ10 toΓ1. This result will help understand the mechanisms of optical transition and the transparent electrode in In2O3.

关 键 词：G0W0-BSE近似 准粒子能带结构 光学性质 吸收机理 

分 类 号：O76[理学—晶体学] O614.372