Manipulation of Light at the Nanoscale for Applications in Energy Conversion
Zongfu Yu, Ginzton Lab, Stanford University
Friday, March 8, 2013, 3:30pm
This seminar is part of the Jones Seminars on Science, Technology, and Society series.
The energy conversion between light and other forms of energy, such as electricity, heat, and fuel, will become increasingly important. Understanding the fundamental light-matter interaction in the context of energy conversion is critically important to advance these technologies. In particular, it is important to understand and explore the new opportunities brought by nanostructures and nanomaterials. I will introduce a nanoscale light management theory for enhancing sunlight absorption in solar cells. This new understanding shows that nano confinement of optical fields can offer light absorption efficiency higher than the Yablonovitch limit, which had been considered by the photovoltaic industry as the upper limit of light absorption for more than two decades. This opens new avenues toward creating highly efficient solar absorbers. Further, I will discuss the energy conversion between heat and light. Thermal extraction will be introduced. It can help a blackbody convert heat to light even more efficiently! This is achieved by enabling internal thermal radiation to tunnel through a sub-wavelength gap. The experimental demonstration will also be described. Thermal extraction could be used in many thermal applications to improve energy efficiency.
About the Speaker
Zongfu Yu is a Physical Science Research Associate in Ginzton Lab at Stanford University. He has given 6 invited talks in major annual conferences of IEEE, OSA, MRS, and SPIE, and many invited seminars in universities. Dr. Yu is a recipient of the Stanford University Postdoc Research Award (2010). He holds a Ph.D. degree (2009) in Applied Physics, an M.S. degree (2008) in Management Science and Engineering, both from Stanford University, as well as a B.S. degree (2004) in Physics from the University of Science and Technology of China.