Centre for Advanced Materials Technology (CAMT), School of Aerospace, Mechanical and Mechatronic Engineering J07, The University of Sydney, Sydney, NSW 2006, Australia.
Chemphyschem. 2011 Dec 23;12(18):3614-8. doi: 10.1002/cphc.201100514. Epub 2011 Oct 20.
Recently, nanostructured silicon-based thermoelectric materials have drawn great attention owing to their excellent thermoelectric performance in the temperature range around 450 °C, which is eminently applicable for concentrated solar thermal technology. In this work, a unified nanothermodynamic model is developed to investigate the predominant factors that determine the lattice thermal conductivity of nanocrystalline, nanoporous, and nanostructured bulk Si. A systematic study shows that the thermoelectric performance of these materials can be substantially enhanced by the following three basic principles: 1) artificial manipulation and optimization of roughness with surface/interface patterning/engineering; 2) grain-size reduction with innovative fabrication techniques in a controllable fashion; and 3) optimization of material parameters, such as bulk solid-vapor transition entropy, bulk vibrational entropy, dimensionality, and porosity, to decrease the lattice thermal conductivity. These principles may be used to rationally design novel nanostructured Si-based thermoelectric materials for renewable energy applications.
最近，基于纳米结构硅的热电材料因其在 450°C 左右的温度范围内的优异热电性能而受到极大关注，这非常适用于集中太阳能热技术。在这项工作中，开发了一个统一的纳米热力学模型来研究决定纳米晶、多孔和纳米结构块状 Si 的晶格热导率的主要因素。系统研究表明，通过以下三个基本原理可以显著提高这些材料的热电性能：1）通过表面/界面图案化/工程进行人为操纵和优化粗糙度；2）通过创新的制造技术以可控的方式减小晶粒尺寸；3）优化材料参数，如体固-汽转变熵、体振动熵、维度和孔隙率，以降低晶格热导率。这些原则可用于合理设计用于可再生能源应用的新型纳米结构硅基热电材料。
