Nanophotonics for Energy Applications

Jifeng Liu, MIT

Friday, November 13, 2009, 3:30pm

Spanos Auditorium

This seminar is part of the Jones Seminars on Science, Technology, and Society series

Energy sustainability has become a critical challenge for modern human society. Improving the energy efficiency of industrial systems and products and reducing the cost of renewable energy are two major technological aspects for energy sustainability. In this talk we will discuss applications of nanophotonic materials and devices in both aspects. In our Information Age, systems for Information Technologies (IT) will potentially dominate the energy consumption in the 21st century at the current growth rate. Electronic-photonic integration based on silicon nanophotonics provides a promising energy efficiency solution for Green IT systems by combining the merits of photons in data transmission with the merits of electrons in data processing on a single microchip. In particular, we will present ultra-low energy consumption germanium-silicon photonic modulators and photodetectors that enables ~100 times increase in energy efficiency for data links or interconnects in computation and communication systems. We are also developing band-engineered germanium optical gain medium on silicon for low-cost and high volume optical power sources in large-scale photonic interconnects. In terms of renewable energy technologies, we will present nanophotonic structures for light-trapping in thin-film solar cells to significantly reduce the material cost of solar energy, as well as optoelectronic materials and structures for efficiency enhancement and cost reduction of thermophotovoltaic devices that convert wasted heat into electricity. With significant impact on energy technologies such as Green IT, renewable energy generation and solid state lighting, nanophotonics will help to "light up" the future of energy sustainability.

About the Speaker

Dr. Jifeng Liu is currently a Postdoctoral Associate with the Microphtonics Center at MIT. He received his Ph.D. in Materials Science and Engineering from MIT in 2006, and M.S. and B.S from Tsinghua University (China) in 2001 and 1999, respectively. His major research interest is energy-efficient, integrated nanophotonic devices for Green Information Technology (IT), as well as nanostructures and nanomaterials for solar cells and thermophotovoltaic (TPV) devices. Since 2000 he has authored or co-authored 35 peer-reviewed journal papers, 2 book chapters, and 28 conference papers. He has also been granted 5 U.S. patents associated with germanium-silicon nanophotonic devices. In 2004, he was awarded a Materials Research Society (MRS) Graduate Student Gold Award at the Fall Meeting.