Zheng Wenwen, Luo Yubo, Liu Yong, Shi Jing, Xiong Rui, Wang Ziyu
Hubei Key Laboratory of Optical Information and Pattern Recognition, School of Mathematics and Physics, Wuhan Institute of Technology, Wuhan 430205, PR China.
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
J Phys Chem Lett. 2019 Sep 5;10(17):4903-4909. doi: 10.1021/acs.jpclett.9b02312. Epub 2019 Aug 13.
Engineering of low-dimensional metal-semiconductor nanocomposites is expected to decouple electrical and thermal property, leading to substantially higher thermoelectric property. In this study, we rationally design a unique 0D-2D Au-SbTe architecture with beneficial interface barrier and strengthened phonon scattering, resulting in synergistically optimized electrical and thermal properties. In-situ growth of Au nanoparticles ∼10 nm on SbTe nanoplates enables better manipulation of electron and phonon transport compared to traditional bulks. The energy barrier between Au and SbTe effectively filters low-energy holes, while the Au nanoparticles competently hinder the propagation of midto-long wavelength phonons. As a result, this unique 0D-2D Au-SbTe composite exhibits a concurrent increase in electrical conductivity and Seebeck coefficient, and a decrease in lattice thermal conductivity, which allows a double of ZT value (∼0.8 at 523 K) for 1 mol % Au-SbTe composites with respect to the pristine SbTe (∼0.39 at 523 K). This self-assembled heterostructure provides a direction to design other low-dimensional metal-semiconductor nanoassemblies for thermoelectric application.
低维金属-半导体纳米复合材料的工程设计有望实现电学和热学性质的解耦，从而显著提高热电性能。在本研究中，我们合理设计了一种独特的0D-2D金-锑碲结构，具有有益的界面势垒和增强的声子散射，从而协同优化了电学和热学性质。与传统块体相比，在锑碲纳米片上原位生长约10纳米的金纳米颗粒能够更好地操控电子和声子输运。金与锑碲之间的能垒有效地过滤了低能空穴，而金纳米颗粒能够有效阻碍中长波长声子的传播。结果，这种独特的0D-2D金-锑碲复合材料的电导率和塞贝克系数同时增加，晶格热导率降低，这使得1摩尔%金-锑碲复合材料的ZT值（523 K时约为0.8）相对于原始锑碲（523 K时约为0.39）提高了一倍。这种自组装异质结构为设计用于热电应用的其他低维金属-半导体纳米组件提供了一个方向。
