应兰州大学材料与能源学院和电镜中心邀请，南方科技大学何佳清教授将于2024年6月14日来我校进行学术交流并做学术报告，欢迎参加！
报告题目：Decouple electron and phonon transport for high-performance thermoelectrics
主讲人：何佳清 教授
邀请人：兰州大学材料与能源学院 彭勇 教授
时间：2024年6月14日上午 9:30
地点：逸夫生物楼一楼电镜中心多功能厅114
报告摘要：Thermoelectrics enable direct heat-to-electricity transformation, but their performance has so far been restricted by the closely coupled electron and phonon transport. The figure of merit, ZT, is the essential measure of thermoelectric performance and can be calculated by ZT = S2σT/κ, where S, σ, κ, and T are Seebeck coefficient, electrical conductivity, total thermal conductivity and absolute temperature, respectively. Although established strategies to optimize ZT usually treat electrical and thermal properties separately, enhancing ZT requires simultaneous optimization of the adversely interdependent S, σ, and κ, which is challenging because most crystal imperfections are believed to scatter both phonons and electrons. This presentation will show that the power factor (S2σ) can be boosted by trap hole release and energy-band engineering including band convergence. The total thermal conductivity can be suppressed by the introduction of all scale defects, high entropy, quantum gap and so on, which provide general methods for boosting their thermoelectric performance. It will also illustrate three typical examples1-5（PbQ/GeTe, Bi2Te3, and AgCrSe2）of emerging excitements in nanostructured materials and systems for thermoelectric materials. It will highlight the role of advanced and classical electron microscopy in unravelling the hierarchical architecture of the constituents and their intimate interplay in governing key phenomena in thermoelectric materials.
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2. Y. Lu, J.Q. He*, et. al., Nature Nanotechnology, 18, 1281 (2023).
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4. B.B. Jiang, J.Q. He*, et. al., Science, 371, 830 (2021).
5. L. Xie, J.Q. He*, et. al., Physical Review Letters, 125, 245901(2020).
简历: Jiaqing He is currently a chair professor at Southern University of Science and Technology (SUSTech). He received his joint Ph.D. degree in physics from both Juelich Research Center and Wuhan University in 2004. He was a postdoc at Brookhaven National Laboratory (2004-2008), research associate (2008-2010) and research assistant professor (2010-2012) at Northwestern University, and a professor at Xi’an Jiaotong University (2012-2013) and SUSTech (2013-2019). His research interests include transmission electron microscopy, thermoelectric materials, and structure and property relationship.