Lee Seunghyeok, Park Gwang Min, Kim Younghoon, Lee So-Hyeon, Jung Sung-Jin, Hong Junpyo, Kim Sung-Chul, Won Sung Ok, Lee Albert S, Chung Yoon Jang, Kim Ju-Young, Kim Heesuk, Baek Seung-Hyub, Kim Jin-Sang, Park Tae Joo, Kim Seong Keun
Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea.
Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588, South Korea.
ACS Appl Mater Interfaces. 2024 Apr 10;16(14):17683-17691. doi: 10.1021/acsami.4c01946. Epub 2024 Mar 26.
Porous thermoelectric materials offer exciting prospects for improving the thermoelectric performance by significantly reducing the thermal conductivity. Nevertheless, porous structures are affected by issues, including restricted enhancements in performance attributed to decreased electronic conductivity and degraded mechanical strength. This study introduces an innovative strategy for overcoming these challenges using porous BiSbTe (BST) by combining porous structuring and interface engineering via atomic layer deposition (ALD). Porous BST powder was produced by selectively dissolving KCl in a milled mixture of BST and KCl; the interfaces were engineered by coating ZnO films through ALD. This novel architecture remarkably reduced the thermal conductivity owing to the presence of several nanopores and ZnO/BST heterointerfaces, promoting efficient phonon scattering. Additionally, the ZnO coating mitigated the high resistivity associated with the porous structure, resulting in an improved power factor. Consequently, the ZnO-coated porous BST demonstrated a remarkable enhancement in thermoelectric efficiency, with a maximum of approximately 1.53 in the temperature range of 333-353 K, and a of 1.44 at 298 K. Furthermore, this approach plays a significant role in enhancing the mechanical strength, effectively mitigating a critical limitation of porous structures. These findings open new avenues for the development of advanced porous thermoelectric materials and highlight their potential for precise interface engineering through the ALD.
多孔热电材料通过显著降低热导率为提高热电性能提供了令人兴奋的前景。然而，多孔结构受到一些问题的影响，包括由于电子电导率降低和机械强度下降导致的性能提升受限。本研究介绍了一种创新策略，通过原子层沉积（ALD）将多孔结构与界面工程相结合，利用多孔BiSbTe（BST）克服这些挑战。通过在BST和KCl的研磨混合物中选择性溶解KCl来制备多孔BST粉末；通过ALD涂覆ZnO薄膜对界面进行工程设计。这种新颖的结构由于存在多个纳米孔和ZnO/BST异质界面，显著降低了热导率，促进了有效的声子散射。此外，ZnO涂层减轻了与多孔结构相关的高电阻率，从而提高了功率因数。因此，涂覆ZnO的多孔BST在热电效率方面有显著提高，在333 - 353 K温度范围内最大值约为1.53，在298 K时为1.44。此外，这种方法在提高机械强度方面发挥了重要作用，有效缓解了多孔结构的一个关键限制。这些发现为先进多孔热电材料的开发开辟了新途径，并突出了通过ALD进行精确界面工程的潜力。
