In-plane thermoelectric properties of graphene/xBN/graphene van der Waals heterostructures
In-plane thermoelectric properties of graphene/xBN/graphene van der Waals heterostructures
复制标题
DOI：
10.1088/1361-648x/acb89e
复制
发表时间：
2023-02
期刊：
影响因子：
--
通讯作者：
S. Makumi;D. Bem;Nicholas Musila;C. Foss;Z. Akšamija
中科院分区：
文献类型：
--
作者：
S. Makumi;D. Bem;Nicholas Musila;C. Foss;Z. Akšamija
二维材料因其独特的电子性质而引起了研究人员的广泛关注，通过将二维层组合成垂直堆叠的货车德瓦尔斯异质结构（vdWHs），可以进一步增强二维材料的电子性质。在2D系统的最佳特性中，热电（TE）能量转换有望实现有针对性的能量转换、局部热管理和热感测。然而，TE转换效率仍然受到导电性和热电性之间的固有权衡的限制。本文利用第一性原理计算研究了由石墨烯层和六方氮化硼（h-BN）组成的石墨烯基vdWHs。我们使用Quantum Espresso计算异质结构系统的电子能带结构，并使用BoltzTrap 2计算其TE性质。我们的研究结果表明，这些2D材料的堆叠层打开了带隙，随着h-BN夹层的数量而增加，这显着提高了功率因数（PF）。我们预测vdWHs的PF为1.0 × 1011 W K−2 m s，几乎是单层石墨烯的5 × 1010 W K−2 m s的两倍。这项研究提供了重要的信息，堆叠层的2D材料的效果，并指向新的途径，以优化TE性能的vdWHs。
2D materials have attracted broad attention from researchers for their unique electronic properties, which may be been further enhanced by combining 2D layers into vertically stacked van der Waals heterostructures (vdWHs). Among the superlative properties of 2D systems, thermoelectric (TE) energy conversion promises to enable targeted energy conversion, localized thermal management, and thermal sensing. However, TE conversion efficiency remains limited by the inherent tradeoff between conductivity and thermopower. In this paper, we use first-principles calculation to study graphene-based vdWHs composed of graphene layers and hexagonal boron nitride (h-BN). We compute the electronic band structures of heterostructured systems using Quantum Espresso and their TE properties using BoltzTrap2. Our results have shown that stacking layers of these 2D materials opens a bandgap, increasing it with the number of h-BN interlayers, which significantly improves the power factor (PF). We predict a PF of ∼1.0 × 1011 W K−2 m s for the vdWHs, nearly double compared to 5 × 1010 W K−2 m s that we obtained for single-layer graphene. This study gives important information on the effect of stacking layers of 2D materials and points toward new avenues to optimize the TE properties of vdWHs.