标题：First-principles study of the effect of BiGaheteroantisites in GaAs:Bi alloy
作者：Li, Dechun ;Yang, Ming ;Zhao, Shengzhi ;Cai, Yongqing ;Lu, Yunhao ;Bai, Zhaoqiang ;Feng, Yuanping
作者机构：[Li, Dechun ;Zhao, Shengzhi ] School of Information Science and Engineering, Shandong University, Jinan 250100, China;[Li, Dechun ;Yang, Ming ;Cai, Yo 更多
来源：Computational Materials Science
摘要：First-principles calculations have been carried out to study effects of BiGaheteroantisite defects in GaAs:Bi on the related electronic structures. Our results show that the heteroantisite defect BiGacan be formed after the isovalent impurity BiAsreaches the solubility limit. This BiGadefect is a deep level donor, and the related defect band is composed of 6s state of BiGahybridized with 4p states of the nearest As atoms. It is also found that the bandgap of GaAs:Bi alloy varies slightly with the increase of Bi compositions, as well as the relative position of the defect level. The co-existing, especially when BiGaand BiAsstay in the first-nearest neighbor, counteract the reduction of the bandgap caused by isovalent impurities BiAsin GaAs:Bi alloy. These results suggest that heteroantisite defect BiGadoes not contribute to the reduction of the bandgap of GaAs:Bi alloy, and might be not an ideal candidate for the bandgap engineering of GaAs:Bi alloy. © 2012 Elsevier B.V. All rights reserved.