Abstract: 
Transport properties of energy carriers, such as electrons, holes, phonons and excitons, determine thermal conductivities of materials, thermoelectric efficiency, photovoltaic efficiency and many other key figures of merits in energy-related applications. However, it is difficult to study behaviors of these energy carriers in macroscale. Ultrafast laser provides a series of methods to reveal microscopic energy carrier dynamics in both time and energy domains with high resolution. In this talk, I will present my work on utilization of ultrafast laser to study electron and phonon dynamics in ultrafast temporal regime. Besides excitation and detection, ultrafast laser is also capable of modulating population or phase of energy carriers, so that creating a platform for studying irregular thermodynamic states.

 

Biography:
Liang Guo received his Bachelor degree in mechanical engineering, Tsinghua University in 2009. He conducted graduate research on nanoscale heat transfer in mechanical engineering, Purdue University. His projects include heat transfer across metal-dielectric interfaces and phonon dynamics in thermoelectric materials. He obtained his PhD degree in 2014. Then, from 2014 to 2017, he did postdoctoral research in chemistry, University of California, Berkeley. The project is to apply femtosecond two-dimensional electronic spectroscopy (2DES) to study energy transfer in two-dimensional semiconductors. He joined mechanical and energy engineering of South University of Science and Technology, China in 2018. He has obtained 1 funding from National Natural Science Foundation and support from Overseas High-Caliber Personnel program, Shenzhen.