Materials Science Research Lecture
Abstract: The synthesis of metal oxide films containing elements of low oxidation potential has been challenging for ultra high vacuum (UHV) approaches. In this talk, I will review these challenges in the context of molecular beam epitaxy (MBE) for the growth of defect-managed oxide thin films and heterostructures. I will present our group's effort to address these challenges using a new radical-based hybrid MBE technique. Using Stannate (BaSnO3 and SrSnO3) as a model material system, I will present a comprehensive growth, and electronic transport study of La-doped BaSnO3 and SrSnO3 yielding a world-record conductivity in optically transparent, doped-BaSnO3 films through defect management. I will present the important role of defects such as dislocations, and non-stoichiometry on electronic transport in addition to discussing different scattering mechanisms that limit the room temperature electron mobility in La-doped BaSnO3. Finally, I will present pathways to enhance electron mobilities towards high room-temperature mobility oxide heterostructures using band structure engineering.
More about the speaker: Bharat Jalan is an Associate Professor and Distinguished Shell Chair in the Department of Chemical Engineering and Materials Science at the University of Minnesota, where he leads the Thin Films and Heterostructure Synthesis Group. His interests are in study of structure-defect-electronic properties relationships of functional oxide films and artificially designed structures. In 2016, he received the biennial International MBE Young Investigator Award and the AFOSR Young investigator award. In 2017 he was awarded with the American Association for Crystal Growth Young Author Award, the AVS Paul Holloway Young Investigator Award, and was named an Emerging Young Investigator by the Royal Society of Chemistry.
Jalan received a BS degree in MSE from Indian Institute of Technology (IIT) Madras in India (2006) and a PhD degree in Materials Science from the University of California, Santa Barbara (2011). He joined the faculty at the University of Minnesota since 2011.