▎ 摘　　要

NOVELTY - Modulation-doped single-crystal graphene pn junction prepared by putting copper foil into reactor and carrying out annealing process, introducing mixed gas into reactor to obtain sub-single layer of intrinsic graphene island on the surface of the copper foil, introducing inert gas and reducing gas into reactor, passing mixed gas into sub-single layer of intrinsic graphene island on surface of copper foil for doping nitrogen, repeating steps and cooling the system to room temperature to stop final growth process, is claimed. USE - The modulation-doped single-crystal graphene pn junction is useful in logic device (claimed), such as inverter and multiplier. ADVANTAGE - The modulation-doped single-crystal graphene pn junction provides good quality, high mobility, and high efficiency to photoelectric conversion. DETAILED DESCRIPTION - Modulation-doped single-crystal graphene pn junction prepared by putting a copper foil into a reactor, and carrying out an annealing process under a reducing atmosphere pressure; (b) introducing carbon source gas and reducing gas of mixed gas into the reactor at 980-1020 degrees C to attain sub-growth to obtain sub-single layer of intrinsic graphene island on the surface of the copper foil; (c) introducing inert gas and reducing gas into the reactor to clean the reactor, while cleaning the reactor the temperature is reduced to be 900-960 degrees C; (d) keeping the temperature of the reactor at 900-960 degrees C, and passing the mixed gas of nitrogen-containing carbon source gas and reducing gas into the sub-single layer of intrinsic graphene island on the surface of the copper foil for doping nitrogen; (e) repeating the above steps for at least twice a time to obtain single stage or multistage graphene pn junction; and (f) cooling the reaction system to room temperature to stop final growth process to obtain deposited on the modulation-doped single-crystal graphene pn junction surface of the copper foil, is claimed.