Growth of Nanocrystalline MoSe2 Monolayers on Epitaxial Graphene from Amorphous Precursors

Abstract

A new approach to the growth of MoSe2 thin films on epitaxial graphene on SiC(0001) by the use of modulated elemental reactants (MER) precursors has been reported. The synthesis applies a two-step process, where first an amorphous precursor is deposited on the substrate which self-assembles upon annealing. Films with a nominal thickness of about 1 ML are successfully grown on epitaxial graphene monolayer as well as buffer layer samples. Characterization of the films is performed using XPS, LEED, AFM, and Raman spectroscopy. The films are nanocrystalline and show randomly rotated domains. This approach opens up an avenue to synthesize a number of new van-der-Waals systems on epitaxial graphene and other substrates.