ABSTRACT
The conduction of heat is one of the fundamental energy transport mechanisms in nature. Traditionally, the phenomenon of heat conduction is believed to follow Fourier’s law, which has received great success in describing macroscopic heat transport and is widely accepted as a general truth. Here the speaker will demonstrate that phonons transport in one-dimensional nanomaterials superdiffusively, which leads to a size-dependent thermal conductivity. In other words, Fourier’s law is not applicable in nano materials. Moreover, using silicon nanowire as an example, different mechanisms of reducing thermal conductivity by phononic engineering will be presented. These features together make semiconducting nanowire a very promising candidate for thermoelectric device applications. Subsequently, the speaker will present their recent theoretical approach for modelling phonon transmission in nanoscale interfacial thermal transport, and strain engineering to enhance interface thermal conductance. Finally, first-principles calculations for the development of nanoelectronics and advanced energy storage are introduced.
BIOGRAPHY
Dr. Zhang received BSc and PhD in physics from Tsinghua University in 1998 and 2002, respectively. Dr. Zhang is currently a senior scientist and capability group manager in Institute of High Performance Computing (IHPC), A*STAR, Singapore, which he joined in February 2013. Prior to his joining IHPC, he was a professor in the Department of Electronics, Peking University. His research is focused on the energy transfer and harvesting in nanostructured materials. He has authored or co-authored more than 150 publications in the peer-reviewed international journals, including 26 published in prestigious journals with impact factor higher than 10, and 9 review articles including one in Review of Modern Physics. His H-index is 41 and total citation is more than 5500. He was awarded the Outstanding Ph.D. thesis Award in Tsinghua University (2002) and Singapore Millennium Foundation Fellowship (2002-2004). His research achievements are also matched with competency in teaching. Three students under his supervision have received the Chinese Government Award for Outstanding Students Studying Abroad.