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 forming a stack including: a) providing: a flat surface, a first set of walls, comprising a first wall and a second wall, and meeting at a corner to form an angle, and a first layer formed of a two-dimensional material in physical contact with the flat surface and with both the first and second walls at the corner, wherein the angle aligns with the crystal structure of the two-dimensional material with a tolerance of up to 5°, wherein a top surface of the first layer is exposed, wherein each of the walls has a length of from 5 nm to 1000 nm, wherein a height of the walls, thereby forming a cavity delimited at least by the top surface and the first set of walls, then b) forming a second layer in the cavity and in physical contact with the exposed top surface of the first layer.

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.

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.