APhMS Special Seminar

**Refreshments outside Noyes at 9:45am

Abstract

The invention of modular materials that are amenable to deterministic, atomically precise manipulation is a pre-requisite for fundamental advances in both electronics and energy conversion/storage. The control of electronic structures at electrode–electrolyte interfaces is key to efficient electrochemical energy conversion processes, and magnetic solids offer some of the most promising solutions to accelerating energy demand by electronic/computing systems. This talk will describe recent insights into controlling these phenomena using two approaches involving the construction of inorganic "superlattices" in 2D materials: (1) We have shown how moiré superlattices of atomically thin layers provide a distinctive platform for manipulating interfacial electron transfer owing to the angle-dependent control over flat electronic bands and spontaneous strain relaxation. (2) We have developed topotactic routes to create two-dimensional magnets and ultraclean magnetic heterostructures that have no bulk analogue. Our work demonstrates how superlattice engineering of bulk crystals can be used to design and pattern macroscopic transport responses in intercalation compounds.

More about the Speaker:

Kwabena was born in Ghana, West Africa. He moved to the US in 2004 for his undergraduate studies in Chemistry at Calvin College, MI, graduating with honors in 2008. After a year working at UOP Honeywell in IL where he researched new catalysts for the petrochemical and gas processing industries, he traveled from the Midwest to the East Coast to begin his graduate studies in Inorganic Chemistry with Prof. Daniel Nocera at MIT (and later Harvard University). His graduate research focused on structural and mechanistic studies of water splitting electrocatalysis at cobalt and nickel compounds. After receiving his Ph.D. in 2015 from Harvard University, Kwabena began postdoctoral research in Prof. Philip Kim's group in the Department of Physics at Harvard, where he studied ion intercalation and quantum transport in 2D van der Waals heterostructures. In July 2018, Kwabena joined the faculty of the UC Berkeley Department of Chemistry, where his group works at the interface of chemistry and physics to leverage degrees of freedom that are unique to atomically thin (so-called two-dimensional, 2D) materials as knobs for tailoring the physics of surfaces to control interfacial chemical reactivity and developing chemical/synthetic approaches for engineering many-body electronic interactions in 2D solids. Since starting his independent career at Berkeley, his awards include the Sloan Research Fellowship, Philomathia Prize, NSF CAREER Award, and DOE Early Career Award.