Jones Seminar: Shining More Light on Energy Sustainability

Jifeng Liu , Assistant Professor of Engineering, Thayer School of Engineering at Dartmouth

Friday, January 8, 2016, 3:30–4:30pm

Spanos Auditorium, Cummings Hall

Energy sustainability has become a critical challenge for modern society, in which energy efficiency and renewable energy are the "twin pillars." In this talk, we present synergistic applications of nanophotonic materials and devices in both aspects, manipulating light on nanoscale to boost the efficiency of solar/thermal energy harvesting as well as data communications in information technology (IT) systems. We will start the presentation with our recent progress in fabricating high quality germanium tin semiconductor thin films on amorphous layers or substrates, opening the door to both 3D photonic integration on Si microchips for Green IT and low-cost virtual substrates on glass/plastics for high efficiency thin film solar cells. To enhance the optical absorption in these thin film photonic devices, we further discuss self-assembled, nano-needle structured tin oxide electrodes for high-efficiency, low-loss “light trapping” in thin-film solar cells and 2D materials (e.g. graphene). The light trapping is so effective that it leads to the visibility of atomically thin (0.35 nm), single layer graphene under naked eyes. Finally, to alleviate the intermittency issue of solar energy, we discuss our research on oxidation-resistant metal/dielectric nanostructures towards air-stable solar thermal absorber coatings for high-temperature concentrated solar power (CSP) systems. These coatings efficiently convert solar energy into heat with minimal thermal radiation losses. They offer great advantages in energy storage compared to solar cells, since storing heated working fluid in CSP system is much easier and much less costly than storing electricity directly. In summary, efficiently manipulating radiated electromagnetic energy, nanophotonics will shine more light on the future of energy sustainability.

About the Speaker

Dr. Jifeng Liu is currently an Assistant Professor at Thayer School of Engineering. He received his BS and MS degrees in materials science and engineering from Tsinghua University, Beijing, China, and his PhD degree from Massachusetts Institute of Technology in 2006. His major research field is nanophotonic materials and devices for energy sustainability, including integrated Si photonics for ultralow energy photonic datalinks as well as nanomaterials and nanostructures for solar thermal and solar photovoltaics. He has authored or co-authored 59 peer-reviewed journal papers, 56 conferences papers, and 6 book chapters. Dr. Liu has also been granted 10 U.S. patents related to nanophotonic materials and devices. He received National Science Foundation (NSF) Faculty Early Career Development (CAREER) Award in 2013. He is also a Senior Member of the Institute of Electrical and Electronics Engineers (IEEE).

For more information, contact Jessica Widdicombe at