Author(s): Wei, JT (Wei Jiang-Tao); Yang, LL (Yang Liang-Liang); Qin, YH (Qin Yuan-Hao); Song, PS (Song Pei-Shuai); Zhang, ML (Zhang Ming-Liang); Yang, FH (Yang Fu-Hua); Wang, XD (Wang Xiao-Dong)

Source: ACTA PHYSICA SINICA Volume: 70 Issue: 4 DOI: 10.7498/aps.70.20201175 Published: FEB 20 2021

Abstract: Through the research in recent decades, one has a comprehensive understanding of the thermoelectric properties of bulk and thin film materials, and made rapid progress of improving the thermoelectric figure of merit ZT, for instance, the maximum ZT values of bismuth telluride related materials, cuprous selenide related materials and tin selenide related materials all exceed 2. However, these bulk materials are still far from the requirements for their practical applications on a large scale. The theoretical calculations show that when bulk thermoelectric materials are made a low-dimensional nanostructured materials, such as two-dimensional nanofilms and one-dimensional nanowires, their thermoelectric properties will be significantly improved. Taking silicon for example, when the bulk silicon is made silicon nanowires, the ZT value increases nearly a hundredfold. Hence, researches of the thermoelectric performances of materials with micro-nano structures have received great attention. However, the measurement of thermoelectric parameters of low-dimensional materials has brought challenges to researchers, for the traditional measurement methods or test platforms designed for bulk materials are no longer suitable for measuring thermoelectric parameters (thermal conductivity, electrical conductivity and Seebeck coefficient) of low-dimensional materials. Therefore, new measurement methods and test platforms need developing. In this case, micro-electromechanical system micro-suspended structure came into being. In this approach used are the separated samples and substrates, and isolated heat transfer channels, with which the thermal parameters of micro/nano materials can be accurately measured, and the sensitivity of thermal conductance can reach 10 PW/K. In this review, the structures of several micro-electromechanical systems used to measure the thermoelectric properties of low-dimensional nanostructures are introduced, including double suspended islands, single suspended islands and suspended four-probe structures. Meanwhile, the fabrication methods and measurement principles of these MEMS structures and thermoelectric properties of micro-nano structure materials are described in detail.

Accession Number: WOS:000623878900027

ISSN: 1000-3290

Full Text: http://wulixb.iphy.ac.cn/article/doi/10.7498/aps.70.20201175