Mahnama Maryam, Meshkinghalam Mostafa, Ozmaian Masoumeh
School of Mechanical Engineering, College of Engineering, University of Tehran, PO Box: 11155-4563, Tehran, Iran.
Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States of America.
J Phys Condens Matter. 2021 Nov 25;34(7). doi: 10.1088/1361-648X/ac3868.
Single-layer black phosphorus (SLBP) also known as phosphorene is a recently introduced two-dimensional material with unique structure and promising physical properties that has drawn considerable attention in the field of nanodevices. This structure demonstrates a high anisotropy in mechanical and thermal behavior along zigzag (ZZ) and armchair (AC) principal in-plane directions. Here in this study, it is shown that implementing shear strain on 10 nm × 50 nm SLBP nanoribbons (SLBPNRs) along ZZ and AC directions, the anisotropy leads to different corrugated patterns on the pristine structure. Applying non-equilibrium molecular dynamics under a parameterized Stillinger-Weber potential for modelling SLBP, thermal conductivity (TC) behavior of the sheared SLBPNRs with corrugated patterns are examined. The results show a higher amplitude and wavelength of the corregations on the ZZ-aligned SLBPNRs, which is around two times higher than that of AC-aligned counterparts. Although, it is also shown that unlike some other 2D materials, such as graphene, the wrinkling does not have such a significant effect on TC of SLBP. The phonon density of states results obtained in this work as well as phonon dispersion curves by first-principle calculations in other works concrete this finding. The results show small frequency shifts in both high- and low-frequency phonons, which are not strong enough to affect TC in SLBPNRs. This interesting thermal property of SLBP under shear strain suggests the great potential application of these corrugated structures in nanodevices without any loss of TC abilities.
单层黑磷（SLBP）也被称为磷烯，是一种最近引入的二维材料，具有独特的结构和有前景的物理特性，在纳米器件领域引起了相当大的关注。这种结构在沿锯齿形（ZZ）和扶手椅形（AC）平面主方向的机械和热行为方面表现出高度各向异性。在本研究中，结果表明，在10纳米×50纳米的SLBP纳米带（SLBPNRs）上沿ZZ和AC方向施加剪切应变时，各向异性会导致原始结构上出现不同的波纹图案。在用于模拟SLBP的参数化斯廷林格 - 韦伯势下应用非平衡分子动力学，研究了具有波纹图案的剪切后SLBPNRs的热导率（TC）行为。结果表明，ZZ取向的SLBPNRs上的波纹具有更高的幅度和波长，比AC取向的对应物高出约两倍。尽管如此，研究还表明，与石墨烯等其他二维材料不同，褶皱对SLBP的TC没有如此显著的影响。本工作中获得的声子态密度结果以及其他工作中通过第一性原理计算得到的声子色散曲线证实了这一发现。结果表明，高频和低频声子都有小的频率偏移，但不足以影响SLBPNRs的TC。SLBP在剪切应变下的这种有趣的热特性表明，这些波纹结构在纳米器件中具有巨大的潜在应用，且不会损失任何TC能力。
