Xu Chunyan, Zhang Jing, Guo Ming, Wang Lingrui
Jilin Engineering Laboratory for Quantum Information Technology, Institute for Interdisciplinary Quantum Information Technology, Jilin Engineering Normal University Changchun 130052 People's Republic of China.
Key Laboratory of Materials Physics of Ministry of Education, Department of Physics and Engineering, Zhengzhou University Zhengzhou 450052 China
RSC Adv. 2019 Jul 26;9(40):23142-23147. doi: 10.1039/c9ra04655k. eCollection 2019 Jul 23.
Inspired by the novel properties of a newly predicted two-dimensional (2D) tetragonal allotrope of Ge called 2D tetragonal Ge, first-principles calculations have been performed to explore the stability, and structural and electronic properties of 2D tetragonal Ge hydrogenation, and the effect of external strain on structural and electronic properties of hydrogenated 2D tetragonal Ge is considered. Our calculations reveal that the hydrogenated 2D tetragonal Ge, α-GeH and β-GeH, are proved to be dynamically and thermally stable. Both α-GeH and β-GeH are semiconductors with a direct band gap of 0.953 eV and indirect band gap of 2.616 eV, respectively. When applying external strain from -7% to 7%, α-GeH is more energetically stable than β-GeH around the equilibrium geometry, β-GeH is more stable than α-GeH when external strains exceed a certain critical value, respectively. The direct band gap of α-GeH reduces rapidly from 2.008 eV to 0.036 eV as external strain increases from -7% to 7%, while the indirect band gap of β-GeH is changed slightly. Our results reveal that α-GeH and β-GeH can offer an intriguing platform for nanoscale device applications and spintronics.
受一种新预测的二维（2D）四方相锗（称为2D四方相Ge）的新奇特性启发，进行了第一性原理计算，以探索2D四方相Ge氢化的稳定性、结构和电子性质，并考虑了外部应变对氢化2D四方相Ge的结构和电子性质的影响。我们的计算表明，氢化的2D四方相Ge，即α-GeH和β-GeH，被证明具有动力学和热稳定性。α-GeH和β-GeH均为半导体，直接带隙分别为0.953 eV，间接带隙分别为2.616 eV。当施加-7%至7%的外部应变时，在平衡几何结构附近α-GeH比β-GeH在能量上更稳定，当外部应变超过某个临界值时，β-GeH比α-GeH更稳定。随着外部应变从-7%增加到7%，α-GeH的直接带隙从2.008 eV迅速降低到0.036 eV，而β-GeH的间接带隙变化较小。我们的结果表明，α-GeH和β-GeH可为纳米级器件应用和自旋电子学提供一个有趣的平台。
