Mind the Gap: The Intercalation of van der Waals Heterostructures: Nano Seminar Series

Seminar: Micro/Nano Electro Mechanical Systems (MEMS): EE | August 31 | 2-3 p.m. | 390 Hearst Memorial Mining Building

 Prof. Kwabena Bediako, UC Berkeley, Chemistry

 Berkeley Nanosciences and Nanoengineering Institute

The assembly of layered (van der Waals, vdW) materials into novel heterostructures relaxes the requirements on crystallographic commensurability across interfaces and enables the creation of atomically precise superlattices that may be synthetically intractable by chemical growth. Inherently, these heterostructures possess artificial two-dimensional (2D) interlayer galleries not present in bulk materials, which may be electrochemically driven to accommodate atoms, ions, or molecules.

This property of acting as an intercalation host material when stacked together makes such vdW layers promising building blocks for innovative energy conversion/storage and electronic technologies.

In this talk, I will discuss the electrointercalation of lithium at the level of singular vdW heterostructures comprised of deterministically stacked 2D layers, enabling the direct resolution of intermediate stages in the intercalation of discrete heterointerfaces and the extent of charge transfer to individual layers.

I will discuss how these results reveal emergent effects distinct from the benefits conventionally associated with hybrid materials in conversion electrodes and how this methodology opens up new pathways to control and characterize charge density in 2D electronic and optoelectronic devices.

Kwabena Bediako completed his PhD in chemistry at Harvard in 2015 and then joined Philip Kim's physics lab for a postdoc. He joins the chemistry faculty here at UCB this July.