物理学报2024，Vol.73Issue(11)：257-264,8.DOI:10.7498/aps.73.20240175
单轴应变对Sb2Se3空穴迁移率的影响
Effect of uniaxial strain on Hole mobility of Sb2Se3
摘要
Abstract
Antimony selenide(Sb2Se3)is a simple-phase,element-rich,and economically friendly material for solar cell absorption layers,with broad application prospects.However,the weak conductivity of Sb2Se3 has become a significant factor limiting the performance of solar cell devices.Carrier mobility is an important electrical parameter for both materials and devices,and strain can change carrier mobility.Therefore,studying the effect of strain on the carrier mobility of Sb2Se3 is of practical significance.In this work,using density functional theory and deformation potential theory,we systematically investigate the influence of uniaxial strain on the band structure,bandgap width,iso-surface,and effective mass of Sb2Se3.We analyze the effects of three types of uniaxial strains along the x-,y-,and z-direction on the carrier mobilities along the x-,y-,and z-direction,which are denoted by μx,μy,and μz,respectively.It is found that under these strains,the valence band maximum(VBM)position of Sb2Se3 remains unchanged,and the bandgap decreases with the increase of strain along the y-and z-direction,while it increases along the x-direction.The variation in bandgap may be related to the coupling strength between the Sb-5p orbital and Se-4p orbital of the conduction band minimum(CBM).For fully relaxed Sb2Se3,its iso-surface exhibits a distorted cylindrical shape,with low dispersion along the z-axis and high dispersion along the x-and y-axis,where μxis greater than μyand μz,suggesting that the x-direction should be considered as the specific growth direction for Sb2Se3 experimentally.When the strain is applied along the x-and z-direction,μxgradually increases with strain increasing,while it decreases when the strain is applied along the y-direction.Taking into account the combined effects of strain on bandgap,iso-surface,density of states,and mobility,this study suggests that the optimal performance of Sb2Se3 solar cell absorber layer material can be realized when the strain is applied along the y-axis,with a compressive strain of 3%.关键词
Sb2Se3/迁移率/形变势/应变工程Key words
Sb2Se3/mobility/deformation potential/strain engineering引用本文复制引用
张冷,沈宇皓,汤朝阳,吴孔平,张鹏展,刘飞,侯纪伟..单轴应变对Sb2Se3空穴迁移率的影响[J].物理学报,2024,73(11):257-264,8.基金项目
国家自然科学基金(批准号:61904071,52002170)、江苏省研究生科技与实践创新计划(批准号:KYCX23_1429)和江苏省高校青蓝工程资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos.61904071,52002170),the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX23_1429),and the Qing Lan Project of Jiangsu Provincial University,China. （批准号:61904071,52002170）
