About Libai's group
Spatial and temporal imaging of energy and charge transport in solar energy conversion systems - We employ ultrafast spectroscopy combined with optical microscopy and scanning probe microscopy to achieve simultaneous ultrafast time resolution and nanometer spatial resolution. This research program aims at providing spatial maps of carrier dynamics, and allowing for imaging energy and charge propagation in space directly. This is an exciting new frontier that combines advanced imaging and dynamics techniques to address fundamental questions regarding energy flow in individual nanostructures, organic materials, solar cells, and photosynthetic systems.
Direct imaging of exciton and charge transport in solar cell active layers
We have recently developed ultrafast microscopy as a novel means to directly visualize exciton and charge transport with ~ 200 fs temporal resolution and ~ 50 nm spatial resolution in perovskite and organic solar cells. Recently, our group has visualized charge transport directly in perovskite solar cells. With innovative approaches that combine spatial and temporal resolutions, we revealed a new singlet-mediated triplet transport mechanism in certain singlet fission materials, which leads to favorable long-range triplet exciton diffusion for solar cell applications.
Probing charge and exciton dynamics at the individual nanostructure level
Our group has pioneered the use of optical pump-probe techniques for imaging ultrafast charge and exciton dynamics at the individual nanostructure level to resolve energy relaxation pathways that are not accessible by traditional ensemble methods. We have spatially resolved carrier dynamics in graphene, individual single-walled carbon nanotubes, and two-dimensional semiconductors such as MoS 2 to elucidate the role of the environment in modulating relaxation pathways.
B.S., Peking University, Beijing, China, 2001;
Ph.D., University of Rochester, 2006;
Career Award, 2016;
Kavli Fellow, Kavli Foundation and National Academy of Sciences, 2011;
Young Investigator Award, Photosynthesis Gordon Research Conference, 2008;
Hooker Graduate Fellowship, University of Rochester, 2005;
DeRight Graduate Fellowship, University of Rochester , 2004;
Lattimore Graduate Fellowship, University of Rochester, 2003.