Elastic Anisotropy and Optic Isotropy in Black Phosphorene/Transition-Metal Trisulfide van der Waals Heterostructures
Elastic Anisotropy and Optic Isotropy in Black Phosphorene/Transition-Metal Trisulfide van der Waals Heterostructures
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DOI：
10.1021/acsomega.9b00011
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发表时间：
2019-02
期刊：
影响因子：
4.1
通讯作者：
B. Sa;Jianhui Chen;Xuhui Yang;Honglei Yang;Jingying Zheng;Chao Xu;Junjie Li;Bo Wu;Hongbing Zhan-Ho
中科院分区：
文献类型：
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作者：
B. Sa;Jianhui Chen;Xuhui Yang;Honglei Yang;Jingying Zheng;Chao Xu;Junjie Li;Bo Wu;Hongbing Zhan-Ho
具有方向相关力学和光学特性的各向异性二维材料近年来引起了人们的广泛关注。在本工作中，基于密度泛函理论计算，通过将众所周知的各向异性黑磷烯（BP）和过渡金属三硫化物MS3 （M = Ti, Hf）组装在一起，理论上提出了范德华（vdW）异质结构中意想不到的弹性各向异性和光学各向异性。从弹性常数、杨氏模量和泊松比可以看出，BP/MS3 vdW异质结构在不同方向上表现出各向异性柔性。我们进一步揭示了它们的ii型带结构性质的物理起源，它们的导带最小值和价带最大值在不同的层中分离。特别是，我们对BP/MS3 vdW异质结构的光学响应函数（包括激子效应）的研究结果表明，它们具有意想不到的光学各向同性，并提高了太阳能转换效率。
Anisotropic two-dimensional materials with direction-dependent mechanical and optical properties have attracted significant attention in recent years. In this work, based on density functional theory calculations, unexpected elastic anisotropy and optical isotropy in van der Waals (vdW) heterostructures have been theoretically proposed by assembling the well-known anisotropic black phosphorene (BP) and transition-metal trisulfides MS3 (M = Ti, Hf) together. It is interesting to see that the BP/MS3 vdW heterostructures show anisotropic flexibility in different directions according to the elastic constants, Young’s modulus, and Poisson’s ratio. We have further unraveled their physical origin of the type-II band structure nature with their conduction band minimum and valence band maximum separated in different layers. In particular, our results on the optical response functions including the excitonic effects of the BP/MS3 vdW heterostructures suggest their unexpected optical isotropies together with the enhancements of the solar energy conversion efficiency.