title: Distribution and self-assisted diffusion of Be and Mg impurities in ZnO.
abstract: The band gap width of the Be-doped ZnO correlates strongly with the distribution of the dopants. By performing first-principles calculations, it is found that an interstitial Be (Bei) atom preferably migrates in a basal plane. During the migration, such a Bei atom favorably bonds to a substituted Be (BeZn) atom, forming a new defect complex (2Be)Zn, showing a trend of aggregation of Be atoms in ZnO. Furthermore, the stability of the defect complex (2Be)Zn can be weakened by a substituted Mg (MgZn). So, the Mg impurities in Be-doped ZnO might suppress the aggregation of Be, so as to significantly improve the effect of the doped Be on modulating the band gap of ZnO.
authors.affiliation: Key Laboratory of Strongly-Coupled Quantum Matter Physics, Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, Anhui, China. bcpan@ustc.edu.cn.
authors.forename: Dingyu
authors.initials: D
authors.lastname: Yong
authors.affiliation: Key Laboratory of Strongly-Coupled Quantum Matter Physics, Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, Anhui, China. bcpan@ustc.edu.cn.
authors.forename: Haiyan
authors.initials: H
authors.lastname: He
authors.affiliation: The Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau, China and State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Zikang
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Key Laboratory of Strongly-Coupled Quantum Matter Physics, Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, Anhui, China. bcpan@ustc.edu.cn.
authors.forename: Bicai
authors.initials: B
authors.lastname: Pan