MackGraphe-Graphene and Nanomaterials Research Center, Mackenzie Presbyterian University, 01302-907 São Paulo, Brazil.
Instituto de Física Teórica, Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), 01140-070 São Paulo, Brazil.
Nat Commun. 2016 Jul 14;7:12191. doi: 10.1038/ncomms12191.
Black phosphorus has recently emerged as a new layered crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and behaviour of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.
黑磷最近作为一种新型层状晶体出现，由于其独特的各向异性晶体和电子能带结构，可能在电子学、光电学和光子学领域有重要的应用。尽管层状晶体的边缘具有一系列奇异的性质，这些性质的表征和利用对于器件的发展至关重要，但黑磷的边缘仍未得到很好的描述。在这项工作中，使用拉曼光谱和密度泛函理论计算实验和理论研究了不同黑磷边缘附近声子的原子结构和行为。偏振拉曼结果表明，在样品边缘出现了新的模式，其光谱取决于边缘的原子结构（锯齿形或扶手椅形）。理论模拟证实，新的模式是由于在体相被禁止的边缘声子态，它们起源于晶格终止的重新排列。
