Xu Biao, Feng Tianli, Li Zhe, Zhou Lin, Pantelides Sokrates T, Wu Yue
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China.
Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, 37235, USA.
Angew Chem Int Ed Engl. 2018 Aug 20;57(34):10938-10943. doi: 10.1002/anie.201805890. Epub 2018 Jul 19.
Nanoengineered materials can embody distinct atomic structures which deviate from that of the bulk-grain counterpart and induce significantly modified electronic structures and physical/chemical properties. The phonon structure and thermal properties, which can also be potentially modulated by the modified atomic structure in nanostructured materials, however, are seldom investigated. Employed here is a mild approach to fabricate nanostructured PbBi Te using a solution-synthesized PbTe-Bi Te nano-heterostructure as a precursor. The as-obtained monoliths have unprecedented atomic structure, differing from that of the bulk counterpart, especially the zipper-like van der Waals gap discontinuity and the random arrangement of septuple-quintuple layers. These structural motifs break the lattice periodicity and coherence of phonon transport, leading to ultralow thermal conductivity and excellent thermoelectric z T.
纳米工程材料可以呈现出与体相晶粒材料不同的独特原子结构，从而引发显著改变的电子结构以及物理/化学性质。然而，声子结构和热性质也可能会受到纳米结构材料中原子结构改变的潜在调制，但却很少被研究。本文采用一种温和的方法，以溶液合成的PbTe-Bi₂Te纳米异质结构为前驱体来制备纳米结构的PbBi₂Te。所得到的整块材料具有前所未有的原子结构，与体相材料不同，特别是拉链状的范德华间隙不连续性和七重-五重层的随机排列。这些结构单元打破了晶格周期性和声子传输的相干性，导致超低的热导率和优异的热电优值zT。
