Description:

Talk Title: Designing and probing novel materials for energy

Abstract: My research group is engaged in fundamental and applied research in novel materials for energy harvesting and storage, nanophotonics, and optoelectronics. The performance of most photovoltaic devices is still limited by their nanoscale behavior. To reveal how the electrical and optical responses vary at relevant length scales, we acquire nanoscale resolved “photographs” and “movies” of the performance of inhomogeneous materials for photovoltaics, by means of novel nanospectroscopic methods. Our measurements provide a tomography of charge carrier generation, recombination, and collection within materials ranging from well-established thin films to emerging perovskites. In particular, we probe the correlation between perovskites’ stability and the chemical changes that occur when the material is exposed to humidity, oxygen, temperature, light, and bias. In the realm of energy storage, the further development of rechargeable, safe batteries requires the understanding of why and how the material is changing upon charging/discharging. We elucidate the dynamics of lithiation/delithiation in all-solid-state batteries through in situ electron microscopy methods to ultimately identify and control undesired chemical reactions that lead to capacity fade. Concerning optical materials, we overcome the constraint imposed by the pre-defined dielectric functions of metals by alloying, where we have recently developed a library of their optical properties. Our approach enables new materials with on demand optical response for applications ranging from electrocatalysis to superabsorbers and color displays. 

Bio: Marina Leite is an Assistant Professor in Materials Science and Engineering, and the Institute for Research in Electronics and Applied Physics at UMD. She has been an invited participant of the National Academy of Engineering 2017 EU-US Frontiers of Engineering Symposium, the awardee of the 2016 APS Ovshinsky Sustainable Energy Fellowship from the American Physical Society (APS), and of the 2014 Maryland Academy of Sciences Outstanding Young Scientist Award. Before joining UMD in 2013, Leite worked for two years at NIST developing nanoscale metrology for functional materials and was a post-doctoral scholar at Caltech (in H. Atwater’s group). She received her PhD in physics from Campinas State University in Brazil and the Synchrotron Light Source Laboratory. Collectively, her group members received 66 awards/honors in the last 4.5 years, including seven NSF-GRF, three honorable mentions, and awards from MRS, IEEE, OSA, ACS, etc. Her research is funded by NSF-DMR, NSF-ECCS, APS, the Army Research Lab, and ARO.