论文标题
2D B $ _4 $ C纳米片的物理和热电特性
Physical and Thermoelectric Properties of 2D B$_4$C Nanosheets
论文作者
论文摘要
硼碳化物（b $ _4 $ c）由于其出色的硬度和用作高温热电学而被理论上和实验性地研究了其散装形式。但是，其二维纳米片的特性尚未确定。在本文中，使用Van der Waals校正的密度功能理论（DFT）模拟，我们表明可以沿不同的方向裂解散装B $ _4 $ C，以形成B $ _4 $ C纳米片，具有低层能量。我们发现，形成能对裂解平面和表面终止的依赖性最小。虽然B $ _4 $ C的状态密度表示是半导体，但发现B $ _4 $ C纳米片主要是金属的。我们将这种金属行为归因于膜表面B-C键的电荷的重新分布。 B $ _4 $ C膜的Seebeck系数仍然与散装的系数相当，并且与温度的函数几乎恒定。我们的结果为实验合成工作和B $ _4 $ c纳米片的未来应用提供了指导，并提供了指导。
Boron carbide (B$_4$C) has been well studied both theoretically and experimentally in its bulk form due to its exceptional hardness and use as a high temperature thermoelectric. However, the properties of its two-dimensional nanosheets are not well established. In this paper, using van der Waals corrected density-functional theory (DFT) simulations, we show that the bulk B$_4$C can be cleaved along different directions to form B$_4$C nanosheets with low formation energies. We find that there is minimal dependence of the formation energies on the cleavage planes and surface terminations. Whilst the density of states of the bulk B$_4$C indicate that it is a semiconductor, the B$_4$C nanosheets are found to be predominantly metallic. We attribute this metallic behaviour to a redistribution of charges on the surface B-C bonds of the films. The Seebeck coefficients of the the B$_4$C films remain comparable to those of the bulk, and are nearly constant as a function of temperature. Our results provide guidance for experimental synthesis efforts and future application of B$_4$C nanosheets in nanoelectronic and thermoelectric applications.
