2D Materials – Physics of van der Waals [hetero]structures
DFG Priority program 2244
Interlayer excitons in advanced, CVD-based van der Waals heterostructures with controlled moiré wavelength
Tobias Korn, Uni Rostock, tobias.korn (at) uni-rostock.de [webpage]
Christian Schüller, Uni Regensburg, christian.schueller (at) physik.uni-regensburg.de [webpage]
Andrey Turchanin, Uni Jena, andrey.turchanin (at) uni-jena.de [webpage]
We will fabricate advanced transition metal dichalcogenide (TMDC) heterostructures with controlled moiré wavelength using TMDC monolayers (MLs) grown by chemical vapor deposition (CVD). This process yields large ML flakes with well-defined triangular shape, directly locked to crystallographic orientation. This allows us to control interlayer twist angles with great accuracy by measuring edge orientations.
We will study interlayer excitons (ILEs) in these advanced heterostructures and systematically determine the influence of the reciprocal space (mis-)alignment and the moiré-induced superlattice potential on ILE energy, photoluminescence lifetimes, valley polarization dynamics and diffusion.
Our CVD process employs Knudsen-type effusion cells to yield large-area TMDC monolayers. From these, we will fabricate TMDC heterostructures using deterministic transfer processes. In parallel, we will develop CVD techniques for single-process growth of heterostructures.
We will use various low-temperature optical spectroscopy techniques, including micro-photoluminescence, Faraday rotation and Kerr microscopy to study these advanced heterostructures.