单轴应变对本征和N掺杂4H-SiC电子结构的影响  

Effect of uniaxial strain on electronic structure of intrinsic and N-doped 4H-SiC

作　　者：秦彦军 张建强 杨慧雅 方峥[3] 范晓珍[1] 邝富丽 叶慧群[1] 方允樟[1] QIN Yan-Jun;ZHANG Jian-Qiang;YANG Hui-Ya;FANG Zheng;FAN Xiao-Zhen;KUANG Fu-Li;YE Hui-Qun;FANG Yun-Zhang(College of Physics and Electronic Information Engineering,Zhejiang Normal University,Jinhua 321004,China;School of Science,Xinjiang Institute of Technology,Aksu 843100,China;Tourism College of Zhejiang,Hangzhou 311231,China)

机构地区：[1]浙江师范大学物理与电子信息工程学院,金华321004 [2]新疆理工学院理学院,阿克苏843100 [3]浙江旅游职业学院,杭州311231

出　　处：《原子与分子物理学报》2025年第3期173-179,共7页Journal of Atomic and Molecular Physics

基　　金：新疆维吾尔自治区自然科学基金(2021D01B47);新疆维吾尔自治区重点研发项目(KYZ04Y21100)。

摘　　要：采用基于密度泛函理论的第一性原理方法,研究了单轴应变对本征和N掺杂4H-SiC电子结构的影响.研究表明应变可以有效调控本征和N掺杂4H-SiC的带隙,在拉应变作用下,带隙单调减小;而在压应变作用下,带隙先增大后减小,当压应变为-1%时,带隙达到最大值.对态密度的分析可知本征和N掺杂4H-SiC的价带顶主要来自Si 3p和C 2p态电子,导带底主要来自Si 3p态电子,C 2p态和Si 3p态通过影响价带顶和导带底从而导致应变结构中带隙发生变化.通过Mulliken布局和差分电荷密度分析可知,随着晶格常数的增加Si原子向C原子和N原子转移的电荷减少,同时Si-C原子和Si-N原子之间的共价性减弱.The effect of uniaxial strain on the electronic structure of intrinsic and N-doped 4H-SiC is investigated by first principles method based on density functional theory.The results show that the strain can effectively regulate the band gap of the intrinsic and N-doped 4H-SiC,and the band gap decreases monotonically under tensile strain.Under compressive strain,the band gap firstly increases and then decreases.When the compressive strain is-1%,the band gap reaches the maximum value.By analyzing the density of states that the valence band maximum of the intrinsic and N-doped 4H-SiC are mainly from the electrons of Si 3p and C 2p states,and the conduction band minimum are mainly from the electrons of Si 3p states.The C 2p states and Si 3p states affect the valence band maximum and conduction band minimum,leading to the change of band gap in the strain structure.Mulliken population and differential charge density analysis show that the charge transfer from the atom of Si to C and N decreases with the increase of lattice constants,and the covalence between Si-C atom and Si-N atom are weakened.

关 键 词：4H-SIC 单轴应变 电子结构 第一性原理 

分 类 号：O471.5[理学—半导体物理]