Marfoua Brahim, Hong Jisang
Department of Physics, Pukyong National University, Busan 48513, Republic of Korea.
Nanomaterials (Basel). 2024 Jan 22;14(2):234. doi: 10.3390/nano14020234.
Traditional thermoelectric materials often face a trade-off between efficient power generation (high ZT) and cooling performance. Here, we explore the potential of achieving simultaneous thermoelectric power generation and cooling capability in the recently fabricated bulk ZrSeTe Janus structure using first-principles density functional theory (DFT). The layered ZrSeTe Janus structure exhibits a semimetal character with anisotropic transport properties along the in-plane and out-of-plane directions. Our DFT calculations, including the explicit calculation of relaxation time, reveal a maximum ZT of 0.065 in the out-of-plane direction at 300 K which is one order of magnitude larger than that in the in-plane direction (ZT0.006). Furthermore, the thermoelectric cooling performance is also investigated. The in-plane direction shows a cooling performance of 13 W/m·K and a coefficient of performance (COP) of ~90 with a temperature difference (ΔT) of 30 K, while the out-of-plane direction has a cooling performance of 2.5 W/m·K and COP of ~2.5. Thus, the out-of-plane current from the thermoelectric power generation can be utilized as an in-plane current source for active heat pumping. Consequently, we propose that the semimetal ZrSeTe Janus structure can display bifunctional thermoelectric properties for simultaneous thermoelectric power generation and active cooling.
传统热电材料通常在高效发电（高热电优值）和冷却性能之间面临权衡。在此，我们使用第一性原理密度泛函理论（DFT）探索在最近制备的块状ZrSeTe 双面结构中实现同时进行热电发电和冷却能力的潜力。层状ZrSeTe双面结构表现出半金属特性，在面内和面外方向具有各向异性的输运性质。我们的DFT计算，包括对弛豫时间的明确计算，揭示在300 K时面外方向的最大热电优值约为0.065，这比面内方向（热电优值约为0.006）大一个数量级。此外，还研究了热电冷却性能。面内方向在30 K的温差（ΔT）下显示出13 W/m·K的冷却性能和约90的性能系数（COP），而面外方向的冷却性能为2.5 W/m·K，COP约为2.5。因此，热电发电产生的面外电流可被用作面内有源热泵的电流源。因此，我们提出半金属ZrSeTe双面结构可展现用于同时进行热电发电和有源冷却的双功能热电特性。
