US Patent 11472708 Method of making graphene structures and devices

A method for the production of a graphene layer structure having from 1 to 100 graphene layers, the method comprising providing a substrate having a thermal resistance equal to or greater than that of sapphire, on a heated susceptor in a reaction chamber, the chamber having a plurality of cooled inlets arranged so that, in use, the inlets are distributed across the substrate and have a constant separation from the substrate, supplying a flow comprising a precursor compound through the inlets and into the reaction chamber to thereby decompose the precursor compound and form graphene on the substrate, wherein the inlets are cooled to less than 100° C., preferably 50 to 60° C., and the susceptor is heated to a temperature of at least 50° C. in excess of a decomposition temperature of the precursor, using a laser to selectively ablate graphene from the substrate, wherein the laser has a wavelength in excess of 600 nm and a power of less than 50 Watts.