密度泛函理论计算半导体材料的带隙误差研究  

Research on Error in Calculating Band Gap of Semiconductor Materials by Using Density Functional Theory

作　　者：张泽群 孙庆德 ZHANG Zequn;SUN Qingde(Beijing Computational Science Research Center,Beijing 100193,China;Graduate School,China Academy of Engineering Physics,Beijing 100193,China)

机构地区：[1]中国工程物理研究院北京计算科学研究中心,北京100193 [2]中国工程物理研究院研究生院,北京100193

出　　处：《济南大学学报（自然科学版）》2021年第6期580-584,共5页Journal of University of Jinan(Science and Technology)

基　　金：国家自然科学基金项目(52002016)。

摘　　要：针对采用局域密度近似或广义梯度近似的密度泛函理论导致半导体材料的带隙计算值偏小的问题,选取砷化镓为研究对象,通过压缩晶格体积调节砷化镓的带隙,利用杂化泛函法与广义梯度近似法计算砷化镓的带隙。结果表明:利用局域密度近似或广义梯度近似法计算的带隙误差会随着砷化镓带隙的减小而减小,但当实际带隙为0时,利用局域密度近似或广义梯度近似法计算的带隙误差仍然存在;引起局域密度近似或广义梯度近似法带隙计算值偏小的主要原因是半导体材料价带的最大值和导带的最小值处波函数的不连续性。In terms of the problem that density functional theory with local density approximation or generalized gradient approximation underestimated band gap calculated values of semiconductor materials,gallium arsenide was selected as the research object and its band gap was adjusted by compressing lattice volume.Hybrid functional method and generalized gradient approximation method were used to calculate the band gap of gallium arsenide.The results show that the band gap error calculated by using local density approximation or generalized gradient approximation method decreases as the band gap of gallium arsenide decreases,but when the actual band gap drops to 0,the band gap error calculated by using local density approximation or generalized gradient approximation method still exists.The main reason for the smaller band gap calculated by using local density approximation or generalized gradient approximation method is the discontinuity of wave function at valence band maximum and conduction band minimum of semiconductor materials.

关 键 词：密度泛函理论 半导体材料 带隙 局域密度近似 广义梯度近似 

分 类 号：O469[理学—凝聚态物理] O471[理学—电子物理学]