物理学报2024，Vol.73Issue(15)：199-205,7.DOI:10.7498/aps.73.20240577
体空位缺陷对氧化铝二次电子发射特性的影响分析
Analysis of effect of bulk vacancy defect on secondary electron emission characteristics of Al2O3
摘要
Abstract
Based on the combination of the first-principles and Monte Carlo method,the effect of vacancy defect on secondary electron characteristic of Al2O3 is studied in this work.The density functional theory(DFT)calculation results show that the band structure changes when the vacancy defects exist.The existence of Al vacancy defects results in a decrease in band gap from 5.88 to 5.28 eV,and in Fermi level below the energy of the valence band maximum as well.Besides,the elastic mean free paths and inelastic mean free paths of electrons in different crystal structures are also obtained.The comparison shows that the inelastic mean free path of electrons in Al2O3 with O vacancy defects is much larger than those of Al2O3 without defects and Al2O3 with Al vacancy defects.When the energy of electrons is smaller than 50 eV,the inelastic mean free path of electrons in Al2O3 without defects is longer than that in Al2O3 with Al vacancy defects.The elastic mean free path of electrons slightly increases when the vacancy defects exist,and the elastic mean free path of electrons in Al2O3 with Al vacancy defects is the largest.In order to investigate the secondary electron emission characteristics under different vacancy defect ratios,an optimized Monte Carlo algorithm is proposed.When the ratio between O vacancy defect and Al vacancy defect increases,the simulation results show that the maximum value of secondary electron yield decreases with the ratio of vacancy defect increasing.The existence of O vacancy defects increases the probability of inelastic scattering of electrons,so electrons are difficult to emit from the surface.As a result,comparing with Al vacancy defect,the SEY of Al2O3 decreases greatly under the same ratio of O vacancy defect.关键词
二次电子/空位缺陷/蒙特卡罗/密度泛函Key words
secondary electron/vacancy defects/Monte Carlo/density functional theory引用本文复制引用
张建威,牛莹,闫润圻,张荣奇,曹猛,李永东,刘纯亮,张嘉伟..体空位缺陷对氧化铝二次电子发射特性的影响分析[J].物理学报,2024,73(15):199-205,7.基金项目
国家自然科学基金(批准号:52307186)、陕西省自然科学基础研究计划(批准号:2023-JC-QN-0585)和陕西省教育厅青年创新团队项目(批准号:23JP104)资助的课题.Project supported by the National Natural Science Foundation of China(Grant No.52307186),the Natural Science Basic Research Program of Shaanxi Province,China(Grant No.2023-JC-QN-0585),and the Youth Innovation Scientific Research Program of the Education Department of Shaanxi Province,China(Grant No.23JP104). （批准号:52307186）
