Sa Baisheng, Li Yan-Ling, Sun Zhimei, Qi Jingshan, Wen Cuilian, Wu Bo
College of Materials Science and Engineering, Fuzhou University, 350108, Fuzhou, People's Republic of China.
Nanotechnology. 2015 May 29;26(21):215205. doi: 10.1088/0957-4484/26/21/215205. Epub 2015 May 7.
Artificial monolayer black phosphorus, so-called phosphorene, has attracted global interest with its distinguished anisotropic, optoelectronic, and electronic properties. Here, we unraveled the shear-induced direct-to-indirect gap transition and anisotropy diminution in phosphorene based on first-principles calculations. Lattice dynamic analysis demonstrates that phosphorene can sustain up to 10% applied shear strain. The bandgap of phosphorene experiences a direct-to- indirect transition when 5% shear strain is applied. The electronic origin of the direct-to-indirect gap transition from 1.54 eV at ambient conditions to 1.22 eV at 10% shear strain for phosphorene is explored. In addition, the anisotropy diminution in phosphorene is discussed by calculating the maximum sound velocities, effective mass, and decomposed charge density, which signals the undesired shear-induced direct-to-indirect gap transition in applications of phosphorene for electronics and optoelectronics. On the other hand, the shear-induced electronic anisotropy properties suggest that phosphorene can be applied as the switcher in nanoelectronic applications.
人工单层黑磷，即所谓的磷烯，凭借其独特的各向异性、光电和电子特性引起了全球关注。在此，我们基于第一性原理计算揭示了磷烯中剪切诱导的直接带隙到间接带隙的转变以及各向异性的减弱。晶格动力学分析表明，磷烯能够承受高达10%的外加剪切应变。当施加5%的剪切应变时，磷烯的带隙经历从直接带隙到间接带隙的转变。我们探究了磷烯在环境条件下从1.54电子伏特的直接带隙到10%剪切应变下1.22电子伏特的间接带隙转变的电子起源。此外，通过计算最大声速、有效质量和分解电荷密度来讨论磷烯中各向异性的减弱，这表明在磷烯用于电子学和光电子学应用中存在不期望的剪切诱导的直接带隙到间接带隙的转变。另一方面，剪切诱导的电子各向异性特性表明磷烯可作为纳米电子应用中的开关。
