Large-area and high-quality single-layer transition metal dichalcogenides can be synthesized by epitaxial growth on single-crystal substrates. An important advantage of this approach is that the interaction between the single-layer and the substrate can be strong enough to enforce a single crystalline orientation of the layer. On the other hand, the same interaction can lead to hybridization effects, resulting in the deterioration of the single-layer's native properties. This dilemma can potentially be solved by decoupling the single-layer from the substrate surface after the growth via intercalation of atoms or molecules. Here we show that such a decoupling can indeed be achieved for single-layer WS2 epitaxially grown on Ag(111) by intercalation of Bi atoms. This process leads to a suppression of the single-layer WS2-Ag substrate interaction, yielding an electronic band structure reminiscent of free-standing single-layer WS2.
@article{arxiv.1811.05748,
title = {Quasi-free-standing single-layer WS2 achieved by intercalation},
author = {Sanjoy K. Mahatha and Maciej Dendzik and Charlotte E. Sanders and Matteo Michiardi and Marco Bianchi and Jill A. Miwa and Philip Hofmann},
journal= {arXiv preprint arXiv:1811.05748},
year = {2018}
}