Title: Two-Dimensional Materials: Interfaces, Edges, and Dopants

Speaker: Geert Brocks (CCER, Twente)
Time: Feb. 13, 2020, 10:00–11:00
Location: Differ, Alexander-zaal

In the wake of graphene, many different types of two-dimensional (2D) materials have been grown or isolated. Monolayers of transition metal di-chalcogenides (TMDCs) MX2, with M=Mo,W, X=S,Se,Te, are direct semiconductors with sizeable band gaps in the range of 1 to 2 eV. Applications in devices not only demand a control over the 2D material’s quality, but also call for carefully designed interfaces with the surroundings, such as metal contacts. I will explain a strategy for making zero-barrier contacts, based upon theoretical insight and DFT calculations, which has meanwhile been verified experimentally. Edges and grain boundaries of TMDC islands often display a one-dimensional (1D) metallic character, which is robust against reconstructions or stoichiometric variations of the edges, and can lead to catalytic activity. I will discuss the origin and type of such 1D metals, and show how to manipulate them. The catalytic activity of a 2D material can be enhanced by transition metal (TM) doping. Time permitting, I will show you how this is done in TM-doped GaN.

The CCER seminars are aimed at researchers interested in computational approaches to (energy) research. The seminar is small-scale, typically 15 participants, and interactive, offering lots of room for discussion. If you don't have access to the DIFFER building but would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it. .