Gold-mediated exfoliation of MoS2 has attracted considerable interest in the recent years. A strong interaction between MoS2 and Au facilitates preferential production of centimeter-sized monolayer MoS2 with near-unity yield and provides a heterostructure system noteworthy from a fundamental standpoint. However, little is known about the detailed nature of the MoS2-Au interaction and its evolution with the MoS2 thickness. Here, we identify specific vibrational and binding energy fingerprints of such strong interaction using Raman and X-ray photoelectron spectroscopy, which indicate substantial strain and charge-transfer in monolayer MoS2. Near-field tip-enhanced Raman spectroscopy reveals heterogeneity of the MoS2-Au interaction at the nanoscale, reflecting the spatial non-conformity between the two materials. Far-field micro-Raman spectroscopy shows that this interaction is strongly affected by the roughness and cleanliness of the underlying Au. Our results elucidate the nature of the strong MoS2-Au interaction and provide guidance for strain and charge doping engineering of MoS2.
@article{arxiv.2004.07133,
title = {Fingerprints of the Strong Interaction between Monolayer MoS2 and Gold},
author = {Matej Velicky and Alvaro Rodriguez and Milan Bousa and Andrey V. Krayev and Martin Vondracek and Jan Honolka and Mahdi Ahmadi and Gavin E. Donnelly and Fumin Huang and Hector D. Abruna and Kostya S. Novoselov and Otakar Frank},
journal= {arXiv preprint arXiv:2004.07133},
year = {2021}
}