Abstract The Janus WSSe monolayer is a new 2D direct band gap material attracting attention due to its unique physical and chemical properties. The lattice thermal conductivity is calculated using the self-consistent approach as well as single-mode relaxation time approximation. We notice that acoustic modes contribute mainly to the lattice thermal conductivity. Thermoelectric properties are investigated using the Seebeck coefficient, electrical conductivity, thermal conductivity, power factor, and figure of merit for pristine WSSe monolayer. The effect of strain on thermoelectric properties is also investigated. Interestingly, the tensile strain resulted in a lowering of the lattice thermal conductivity from 25.37 to 9.90 W m−1K−1. The valley degeneracy with biaxial strain in the valence and conduction band edges enhances the power factor. Thus, strain ultimately, improves the figure of merit from 0.72 (0.73) to 1.06 (1.08) under biaxial strain for n(p) carriers at 5 × 1020 cm−3 and 7 × 1020 cm−3, respectively. The thermoelectric efficiency of biaxial stained monolayer based device improved about 29% at 1500 K. These studies provide an avenue to engineer the thermoelectric properties using strain mediated valley degeneracy as the external stimuli.

中文翻译：

---

通过诱导应变介导的谷简并增强 Janus WSSe 单层的热电性能

摘要 Janus WSSe 单层是一种新型的二维直接带隙材料，因其独特的物理和化学性质而备受关注。使用自洽方法以及单模弛豫时间近似计算晶格热导率。我们注意到声学模式主要有助于晶格热导率。使用原始 WSSe 单层的塞贝克系数、电导率、热导率、功率因数和品质因数来研究热电特性。还研究了应变对热电特性的影响。有趣的是，拉伸应变导致晶格热导率从 25.37 降至 9.90 W m-1K-1。价带和导带边缘中双轴应变的谷简并增强了功率因数。因此，应变最终将 n(p) 载流子的双轴应变下的品质因数从 0.72 (0.73) 提高到 1.06 (1.08)，分别为 5 × 1020 cm-3 和 7 × 1020 cm-3。基于双轴染色单层的器件的热电效率在 1500 K 时提高了约 29%。这些研究提供了使用应变介导的谷简并作为外部刺激来设计热电特性的途径。