Prof. Yuanhua Lin
School of Materials Science & Engineering, Tsinghua University, China

Biography: Professor Yuan-Hua Lin is the Professor Cheung Kong Scholars, and Dean of School of Materials Science & Engineering of Tsinghua University. He received his PhD in the Department of Materials Science & Engineering from Tsinghua University in 2001. He joined University of Tokyo as a postdoc (2004-2006). He was awarded as Distinguished Scholar of National Natural Science Foundation in 2010, Young Researcher Award of the Chinese Ceramic Society in 2007. 2nd-class Award of Science and Technology of Ministry of Education in 2009, etc. Prof. Lin has authored/ co-authored over 200 publications, and his entire publications have been cited for over 13,100 times, and h index is 62. He also obtained 20 patents and gave about 60 invited talks.

Prof. Lin’s research interests are functional oxide-based ceramics and thin films, including (1) High κ ceramic films and nanocomposites for high energy density capacitors applications; (2) High-temperature Oxides thermoelectric materials and devices for energy conversion; (3) Photoluminescence and photo-catalytic oxide nanostructured materials.

Speech Title: High-Performance Oxides-Based Thermoelectric Ceramics for Energy Conversion

Abstract: TThermoelectric materials have attracted much more attention due to their wide applications. In comparison with thermoelectric alloys, oxide semiconductors, which are thermally and chemically stable in air at high temperature, are regarded as the candidates for high-temperature thermoelectric applications. We prepared nanostructured p-type BiCuSeO and n-type In₂O₃-based ceramics by Spark plasma sintering. Our results indicate that the nano-grained size and band gap engineering can effective scatter the low and mid-frequency phonons to smaller than grain size, resulting in 50% reduction of thermal conductivity compared with that of the 2 μm grained sample, and ZT can be enahnced greatly. A high performance thermoelectric oxyselenide BiCuSeO ceramic with ZT>1.5 at 823 K is obtained. The band gap engineering and nanostructures can effectively tune its electronic structure, hole concentration and thermal conductivity, resulting in substantially enhanced mobility, power factor and thus ZT value.