Controlling interlayer excitons in MoS2 layers grown by chemical vapor deposition
Ioannis Paradisanos, Shivangi Shree, Antony George, Nadine Leisgang, C. Robert, Kenji Watanabe, Takashi Taniguchi, Richard J. Warburton, Andrey Turchanin, X. Marie, Iann C. Gerber, Bernhard Urbaszek
Abstract
Abstract Combining MoS 2 monolayers to form multilayers allows to access new functionalities. Deterministic assembly of large area van der Waals structures requires concrete indicators of successful interlayer coupling in bilayers grown by chemical vapor deposition. In this work, we examine the correlation between the stacking order and the interlayer coupling of valence states in both as-grown MoS 2 homobilayer samples and in artificially stacked bilayers from monolayers, all grown by chemical vapor deposition. We show that hole delocalization over the bilayer is only allowed in 2H stacking and results in strong interlayer exciton absorption and also in a larger A-B exciton separation as compared to 3R bilayers. Comparing 2H and 3R reflectivity spectra allows to extract an interlayer coupling energy of about t ⊥ = 49 meV. Beyond DFT calculations including excitonic effects confirm signatures of efficient interlayer coupling for 2H stacking in agreement with our experiments.