Platform of large metal nitride islands with lateral orientations and low-defect density

A process the preparation a metal nitride platform for active devices, said process comprising the steps of:

• (a) depositing a pre-defined array of catalyst sites with intervening distances, on a substrate, wherein a material for the pre-defined array of catalyst sites is selected from a layered material, preferably graphene, molybdenum disulphide (MoS2) or tungsten disulphide (WS2), or a combination thereof;
• (b) growing metal nitride islands, selectively, only on said pre-defined array of catalyst sites, by placing said substrate in a reaction chamber, in the presence of a reactive gas and precursors and under preferred reaction conditions;
• (c) growing said metal nitride islands with lateral to vertical size ratios of at least greater than one (1), such that top surfaces of said metal nitride islands are with reduced dislocation densities, wherein dislocations that originate from lower portions of said metal nitride islands and growing vertically and encounter side walls of said metal nitride islands undergo lateral deviations, wherein a root mean square (RMS) roughness of the top surfaces of the metal nitride islands is less than 1 nm;
• and
• (d) growing, optionally, an epitaxial layer on said metal nitride islands.