Event
Transforming Energy Lecture - Dr. Ju Li
Wednesday, September 2, 2015
5:00 p.m.
1110 Kim Engineering Building
Amanda McCrum
301 405 9378
amccrum@umd.edu
http://www.umerc.umd.edu/transforming-energy-lectures
Dr. Ju Li, Battelle Energy Alliance Professor of Nuclear Science and Engineering, Massachusetts Insitute of Technology
Abstract: Recently, an emergent class of materials named ‘ultrastrength materials’ [Prog. Mater. Sci. 55 (2010) 710] have been shown to avoid inelastic relaxation up to a significant fraction of their ideal strength. Here, we illustrate computationally and experimentally that elastic strain is a viable agent for creating a continuously varying bandgap profile [Nature Photonics 6 (2012) 866; Nature Communications 6 (2015) 7381] in an initially homogeneous, atomically thin membrane. We propose that a photovoltaic device made from a strain-engineered MoS2 monolayer will capture a broad range of the solar spectrum and concentrate excitons or charge carriers. The concept can be generalized to bending [ACS Nano 5 (2011) 3475], interlayer twist [Nano Letters 14 (2014) 5350] and slip [Nano Letters 15 (2015) 1302], which lead to tunable, low-energy artificial atoms, artificial superlattices and pseudoheterostructures that can regulate excitonic [Adv. Mater. 26 (2014) 2572] and electronic motions. By controlling the elastic strain field statically or dynamically, one opens up a much larger parameter space for optimizing the functional properties of materials, which gives a new meaning to Feynman’s 1959 statement “there's plenty of room at the bottom” [MRS Bulletin 39 (2014) 108].
Biography: Ju Li is BEA Professor of Nuclear Science and Engineering and Professor of Materials Science and Engineering at MIT. His group (http://Li.mit.edu) performs computational and experimental research on mechanical properties of materials, and energy storage and conversion. Ju obtained a PhD degree in nuclear engineering from MIT in 2000, and Bachelor's degree in Physics from University of Science and Technology of China in 1994. He is a recipient of the 2005 Presidential Early Career Award for Scientists and Engineers, 2006 MRS Outstanding Young Investigator Award, and 2007 TR35 award from Technology Review magazine. Thomson Reuters included Ju in its Highly Cited Researchers list in 2014, among 147 global scientists in the Materials Science category. Ju was elected Fellow of the American Physical Society in 2014.
