2D Materials

Overview

The isolation of single-atomic layer graphene has led to a surge of interest in other layered crystals with strong in-plane bonds and weak, van der Waals, interlayer coupling. We research new optical properties of two-dimensional (2D) materials extracted from layered bulk crystals. We've published work on MoS₂, MoSe₂, WSe₂, WS₂, CrBr₃, GaSe, GaTe, InSe, MnPSe, NiPS, ZrSe, HfSe, GaS, hBN as well as heterostructures (vertical stacks) and nanophotonic structures made from some of these materials.

In their bulk form layered materials may vary from insulators to semiconductors, from metals to superconductors, and show magnetic and topological insulator properties. We extract 2D films by mechanical exfoliation from layered crystals called van der Waals crystals after the weak forces holding their atomic planes together.

Properties of few-atomic-layer 2D films differ from those in bulk quite dramatically. For example, some indirect band-gap semiconductors turn to direct band-gap ones and become optically active. Our recent focus is on using these 2D films as building blocks or intrinsic parts of hybrid nanophotonic devices.

2D Materials group on a sunny and very cold day in January 2024

Left to right: Alex, Panaiot, Oscar, Sasha, Sattar, Stephen, Sam, Dan, Paul, Xuerong, Oscar, Tim, Zara, Yadong