Zhang Yunzhen, Ye Han, Yu Zhongyuan, Gao Han, Liu Yumin
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications Beijing 100876 China
RSC Adv. 2018 Feb 13;8(13):7022-7028. doi: 10.1039/c8ra00369f. eCollection 2018 Feb 9.
First-principles calculations are carried out to systematically investigate the structural and electronic properties of point defects in hydrogenated GaBi and InBi monolayers, including vacancies, antisites and Stone-Wales (SW) defects. Our results imply that the perfect H-Ga(In)Bi is a semiconductor with a bandgap of 0.241 eV (0.265 eV) at the point. The system turns into a metal by introducing a Ga(In) vacancy, substituting a Bi with a Ga(In) atom or substituting an In with a Bi atom. Other defect configurations can tune the bandgap value in the range from 0.09 eV to 0.3 eV. In particular, the exchange of neighboring Ga(In) and Bi increases the bandgap, meanwhile the spin splitting effect is preserved. All SW defects decrease the bandgap. The lowest formation energy of defects occurs when substituting a Ga(In) with a Bi atom and the values of SW defects vary from 0.98 eV to 1.77 eV.
进行第一性原理计算，以系统地研究氢化GaBi和InBi单层中各种点缺陷的结构和电子性质，包括空位、反位缺陷和斯通-威尔士（SW）缺陷。我们的结果表明，完美的H-Ga(In)Bi是一种半导体，在Γ点处带隙为0.241 eV（0.265 eV）。通过引入Ga(In)空位、用Ga(In)原子取代Bi原子或用Bi原子取代In原子，该体系会转变为金属。其他缺陷构型可将带隙值调整在0.09 eV至0.3 eV范围内。特别地，相邻的Ga(In)和Bi的交换会增加带隙，同时自旋分裂效应得以保留。所有的SW缺陷都会减小带隙。当用Bi原子取代Ga(In)时，缺陷的形成能最低，SW缺陷的值在0.98 eV至1.77 eV之间变化。
