Abstract: In one aspect, a method of depositing a transition metal dichalcogenide is provided. The method includes depositing a layer of the transition metal dichalcogenide on a substrate by a metalorganic chemical vapor deposition process including exposing the substrate to a mixture of reactant gases including a transition metal precursor and a chalcogen precursor. The mixture further includes a gas-phase halogen-based reactant to volatilize transition metal adatoms deposited on the substrate.

Abstract: In one aspect, a template for growing a crystal of a two-dimensional material can include a flat surface for growing the crystal thereon, a first wall on the flat surface, and a second wall on the flat surface. The first and the second walls can meet at a corner to form an angle having an opening that is adapted to align with the crystal structure of the crystal with a tolerance of up to 5°. Each of the first and second walls can have a length of from 5 nm to 1000 nm and a height of from 0.6 nm to 2 nm.

Abstract: A method for providing a film of one or more monolayers of transition metal dichalcogenides on a substrate is disclosed. The method includes providing a substrate; depositing at least one monolayer of the transition metal dichalcogenides on the substrate; and selectively removing superficial islands on top of the at least one monolayer by thermal etching.