New 2D layered materials WX₂N₄(X≐Si, Ge)¹ are suitable for thermoelectric applications for a pretty good value of the figure of merit (ZT). Here, the thermoelectric properties of the 2D monolayer of WX₂N₄(X≐Si, Ge) using Density Functional Theory (DFT) is investigated combined with Boltzmann Transport Equation (BTE) along with spin-orbit coupling (SOC). An excellent thermoelectric $ZT$ of 0.91 (0.92 with SOC) is obtained at 900 K for p-type WGe₂N_4, and a $ZT$ of 0.81 (0.86 with SOC) is observed for n-type at the same temperature. Furthermore, the WGe₂N₄ showed a $ZT$ of more than 0.7 (0.79 with SOC) at room temperature for p-type. On the other hand, the WSi₂N₄ showed a comparatively lower $ZT$ at room temperature. However, the $ZT$ value increases significantly at higher temperatures, reaching 0.72 (0.79 with SOC) and 0.71 (0.62 with SOC) for p and n-type at 900 K, respectively. The electronic band structure is examined and discovered that WSi₂N₄ and WGe₂N₄ possess indirect bandgaps (BG) of 2.68 eV (2.57 eV with SOC) and 1.53 eV (1.46 eV with SOC), respectively, according to Heyd-Scuseria-Ernzerhof (HSE) approximation. These materials may also be useful in UV and visible range optoelectronic devices because of their strong absorption in the respective regions.

中文翻译：

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WX2N4(X≐Si, Ge)单层热电性能和光电性能的策略比较。

新型二维层状材料 WX ₂ N ₄ (X≐Si, Ge) ¹适用于热电应用，具有相当好的品质因数 (ZT)。在这里，结合玻尔兹曼输运方程（BTE）和自旋轨道耦合（SOC），使用密度泛函理论（DFT）研究了WX ₂ N ₄ （X≐Si，Ge）的二维单层的热电性质。优良的热电$Z\mathrm{时间}$_{对于 p 型 WGe 2} N _4，在 900 K 时获得 0.91（对于 SOC 为 0.92） ，并且$Z\mathrm{时间}$在相同温度下，观察到 n 型的值为 0.81（SOC 为 0.86）。此外，WGe ₂ N ₄显示出$Z\mathrm{时间}$对于 p 型，室温下超过 0.7（SOC 为 0.79）。另一方面，WSi ₂ N ₄表现出相对较低的$Z\mathrm{时间}$在室温下。但是，那$Z\mathrm{时间}$值在较高温度下显着增加，p 型和 n 型在 900 K 时分别达到 0.72（SOC 为 0.79）和 0.71（SOC 为 0.62）。根据 Heyd-Scuseria 的说法，检查电子能带结构后发现，WSi ₂ N ₄和 WGe ₂ N ₄分别具有 2.68 eV（SOC 为 2.57 eV）和 1.53 eV（SOC 为 1.46 eV）的间接带隙（BG）。 -Ernzerhof (HSE) 近似。这些材料也可用于紫外和可见光范围的光电器件，因为它们在各自区域具有强吸收性。