计算物理 ›› 2017, Vol. 34 ›› Issue (6): 713-721.

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Zn空位对Al-P共掺杂ZnO电子结构影响的第一性原理计算

李磊磊2, 李维学1,2, 戴剑锋1,2, 王青2   

  1. 1. 兰州理工大学, 省部共建有色金属先进加工与再利用国家重点实验室, 兰州 730050;
    2. 兰州理工大学理学院, 兰州 730050
  • 收稿日期:2016-09-12 修回日期:2016-12-21 出版日期:2017-11-25 发布日期:2017-11-25
  • 作者简介:李磊磊(1992-),男,硕士研究生,E-mail:heatj@foxmail.com;李维学(1963-),教授,博士,主要从事半导体材料第一性原理计算仿真研究,E-mail:lwx@lut.cn
  • 基金资助:
    国家自然科学基金(50873047)及甘肃省科技计划(1010RJZA045)资助项目

Effects of Zinc Vacancies on Electronic Structure of Al-P Co-doped ZnO:First-principles Calculations

LI Leilei2, LI Weixue1,2, DAI Jianfeng1,2, WANG Qing2   

  1. 1. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China;
    2. School of Sciences, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2016-09-12 Revised:2016-12-21 Online:2017-11-25 Published:2017-11-25

摘要: 采用第一性原理平面波赝势法计算ZnO(Al,P)体系的晶格参数和电子结构,重点分析Zn空位对体系晶体结构、形成能、态密度的影响.计算结果表明:Al和P共掺杂过程中,AlZn-PZn有更低的形成能,能带分析呈现n型.并随着Zn空位浓度的增大使得掺杂后的晶胞体积减小,晶格常数c先增大后减小.存在Zn空位的掺杂体系形成能比AlZn-PO掺杂体系低,体系较稳定.能带分析呈现p型趋势.Al和P以1∶2的比例掺杂时,体系的形成能降低,体系更稳定;同时,比较1个VZn和2个VZn的AlZn-PZn共掺杂体系的能带结构发现,随着Zn空位浓度增大,带隙增大,体系p型化特征增强.AlZn-2PZn共掺杂体系带隙减小为0.56 eV,更有利于提高其导电性质.然而出现2VZn后,带隙增大为0.73 eV,小于本征ZnO带隙,p型化程度更强烈;此外态密度分析表明2VZn的AlZn-2PZn共掺杂使得态密度更加分散,更多的电子穿过费米能级使得p型化更明显.因此,将Al/P按1∶2的比例共掺且Zn空位增至2个时,可以获得导电性能更好的p型ZnO.

关键词: Al-P共掺杂, 第一性原理, Zn空位, 电子结构

Abstract: With pseudo-potential plane-wave based on density functional theory (DFT), effects of zinc vacancies on ZnO lattice parameters and electronic structure of Al-P co-doped were studied. Formation energy, density of states are analysed. It shows that AlZn-PZn has the lowest formation energy and presents n-type in the process of co-doping. Presence of zinc vacancies make cell volume decrease, and lattice constant c increase and decreases as concentration of zinc vacancies increase. According to formation energy of co-doping, formation of zinc vacancies system is more stable than AlZn-PO. System with Al and P ratio of 1:2 co-doping can reduce formation energy and become more stable. With comparisons of band structure of VZn and 2VZn, it is found that band gap increased with zinc vacancies increasing, which makes p-type ZnO more obvious and enhances conductivity of AlZn-2PZn co-doping systems. However, for AlZn-2PZn co-doping of 2VZn, it shows great superiority of p-type. According to state density analysis, AlZn-2PZn of 2VZn makes the state density more diffuse, and go through the Fermi level, which leads to formation of obvious p-type. As a result, better p-type ZnO can be obtained by controlling Al/P in proportion of 1:2 co-doing with zinc vacancy to 2VZn.

Key words: Al-P co-doping, first principles, zinc vacancies, electronic structure

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