Saiz Fernan, Carrete Jesús, Rurali Riccardo
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB Bellaterra 08193 Spain
Institute of Materials Chemistry, TU Wien Getreidemarkt 9 1060 Vienna Austria
Nanoscale Adv. 2020 Oct 14;2(11):5352-5361. doi: 10.1039/d0na00518e. eCollection 2020 Nov 11.
The goal of this work is to investigate the influence of mechanical deformation on the electronic and thermoelectric properties of ZrS monolayers. We employ density functional theory (DFT) calculations at the hybrid HSE06 level to evaluate the response of the electronic band gap and mobilities, as well as the thermopower, the electrical conductivity, the phononic and electronic contributions to the thermal conductivity, and the heat capacity. Direct examination of the electronic band structures reveals that the band gap can be increased by up to 17% under uniaxial strain, reaching a maximum value of 2.32 eV. We also detect large variations in the electrical conductivity, which is multiplied by 3.40 under a 4% compression, but much smaller changes in the Seebeck coefficient. The effects of mechanical deformation on thermal transport are even more significant, with a nearly five-fold reduction of the lattice thermal conductivity under a biaxial strain of -4%. By harnessing a combination of these effects, the thermoelectric figure of merit of strained ZrS could be doubled with respect to the unstrained material.
这项工作的目标是研究机械变形对ZrS单层的电子和热电性能的影响。我们采用混合HSE06水平的密度泛函理论（DFT）计算来评估电子带隙和迁移率的响应，以及热功率、电导率、声子和电子对热导率的贡献和热容。对电子能带结构的直接检查表明，在单轴应变下带隙可增加高达17%，达到最大值2.32 eV。我们还检测到电导率有很大变化，在4%压缩下电导率乘以3.40，但塞贝克系数的变化要小得多。机械变形对热传输的影响更为显著，在-4%的双轴应变下晶格热导率几乎降低了五倍。通过利用这些效应的组合，应变ZrS的热电优值相对于未应变材料可以翻倍。
