Seminar Link: Picoelectrodynamics Theory Network - YouTube
Abstract
The intercalation of layered compounds is a promising route for the scalable synthesis of 2D heterostructures with novel emergent optoelectronic properties. Here, we investigate, via first-principles calculations, the intercalation of zerovalent metals within the van der Waals gap of bulk MoS2. Specifically, we focus on Cu-MoS2 and Sn-MoS2 hybrids that can accommodate clusters to uniform, continuous 2D metallic layers of metallic Cu within the vdW gap of MoS2. We study the evolution of the Cu-MoS2 and Sn-MoS2 hybrids with increasing metal content and examine the consequences for intercalation energetics and optoelectronic properties as the intercalated metals evolve from disordered clusters to contiguous layers. We identify emergent interfacial plasmons (1-2 eV range) that are unique to these intercalated materials, arising from resonant 2D metallic states within the MoS2 band gap. Our calculations are shown to be in good agreement with experiments and help explain the enhanced infrared absorption of the Cu-MoS2 and Sn-MoS2 hybrids. Overall, our results indicate that the intercalation of zerovalent metals in layered materials offers a facile and scalable approach for designing hybrid 2D heterostructures with tunable optoelectronic properties for device applications.
By Prof. Ashwin Ramasubramaniam
Prof. Ashwin Ramasubramaniam is a Professor of Mechanical & Industrial Engineering and the Program Director of the Materials Science & Engineering Graduate Program at the University of Massachusetts Amherst, MA. He obtained his B. Tech in Mechanical Engineering from IIT Bombay (1999), M.Sc. in Engineering (2002), M. Sc. in Applied Mathematics (2002), and Ph.D. in Engineering (2005) from Brown University. He is a recipient of several awards including the DOE Early Career Research Award (2013), the Minerals, Metals, and Materials Society Young Leader Professional Development Award (2012), the University of Massachusetts Amherst Exceptional Merit Award (2014), and the MRS Graduate Student Silver Award (2004). His research focuses on employing computational methods, notably many-body perturbation theory, density functional theory, continuum mechanics, and molecular dynamics, to investigate materials at length scales ranging from the nano- to the macroscale.