State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
Phys Chem Chem Phys. 2018 Oct 7;20(37):24250-24256. doi: 10.1039/c8cp04069a. Epub 2018 Sep 13.
Single-layered two-dimensional (2D) materials have become very attractive due to their novel electronic behavior after the discovery of graphene. Here, we report the electronic structure and thermoelectric properties of single-layered 2D selerium (selenene) and tellurium (tellurene) by using density functional theory calculation. Both selenene and tellurene show three-phonon limited thermal conductivity. The prominent anharmonic phonon scattering process for tellurene makes it show the lowest lattice thermal conductivity among 2D single elemental materials till now. Their special square unit cells give rise to a highly anisotropic electronic structure along the zigzag and the armchair direction. The large effective mass and Seebeck coefficient along the armchair direction suggest that the thermal performance is better than that of the zigzag direction. The effect of spin-orbit coupling increases the band gap and is found to be crucial for tellurene. These studies provide a way to tune the thermoelectric properties of selenene and tellurene in the future.
由于在发现石墨烯之后其具有新颖的电子行为，单层二维（2D）材料变得非常有吸引力。在这里，我们通过使用密度泛函理论计算报告了单层 2D 硒（硒烯）和碲（碲烯）的电子结构和热电性质。硒烯和碲烯都表现出三声子限制的热导率。碲烯中突出的非谐声子散射过程使其在 2D 单元素材料中表现出迄今为止最低的晶格热导率。它们特殊的正方形单元导致在锯齿形和扶手椅方向上具有高度各向异性的电子结构。沿扶手椅方向的有效质量和塞贝克系数较大表明热性能优于锯齿形方向。自旋轨道耦合的影响增加了带隙，并且被发现对碲烯至关重要。这些研究为未来调节硒烯和碲烯的热电性质提供了一种方法。
