Suwardi Ady, Hu Lei, Wang Xizu, Tan Xian Yi, Repaka Durga Venkata Maheswar, Wong Lai-Mun, Ni Xiping, Liew Weng Heng, Lim Su Hui, Yan Qingyu, Xu Jianwei, Zheng Yun, Hippalgaonkar Kedar
Institute of Materials Research and Engineering, Agency for Science, Technology and Research , #08-03, 2 Fusionopolis Way , Singapore 138634.
School of Material Science and Engineering , Nanyang Technological University , Singapore 639798.
ACS Appl Mater Interfaces. 2020 Feb 26;12(8):9150-9157. doi: 10.1021/acsami.9b17269. Epub 2020 Feb 12.
Phosphide-based thermoelectrics are a relatively less studied class of compounds, primarily due to the presence of light elements, which result in high thermal conductivity and inherent stability problems. In this work, we present a stable phosphide-tetrahedrite, AgGeP, which possesses the highest (∼0.7) among all known phosphides at intermediate temperatures (750 K). We examine the intrinsic electronic and thermal transport properties of this compound by expressing the transport properties in terms of weighted mobility (μ), transport coefficient (σ), and material quality factor (), from which we are able to elucidate that the origin of its high can be attributed to the platelike Fermi surface and high level of band multiplicity related to its complex band structure. Finally, we discuss the origin of the low lattice thermal conductivity observed in this compound using experimental sound velocity, elastic properties, and Debye-Callaway model, thus laying the foundation for similar stable phosphides as potentially earth-abundant and nontoxic intermediate-temperature thermoelectric materials.
基于磷化物的热电材料是一类研究相对较少的化合物，主要是因为其中存在轻元素，这导致了高的热导率和固有的稳定性问题。在这项工作中，我们展示了一种稳定的磷化物-黝铜矿，即AgGeP，它在中间温度（750K）下在所有已知磷化物中具有最高的（约0.7）。我们通过用加权迁移率（μ）、传输系数（σ）和材料品质因数（）来表示传输特性，研究了该化合物的本征电子和热传输特性，从中我们能够阐明其高的起源可归因于其板状费米面以及与其复杂能带结构相关的高能带多重性水平。最后，我们使用实验声速、弹性性质和德拜-卡拉威模型讨论了在该化合物中观察到的低晶格热导率的起源，从而为类似的稳定磷化物作为潜在的储量丰富且无毒的中间温度热电材料奠定了基础。
