Method of growing a graphene coating or carbon nanotubes on a catalytic substrate

A method of growing a graphene coating on a catalytic substrate by chemical vapor deposition, wherein the catalytic substrate is a copper, copper-metal alloy, or semiconductor Ge catalytic substrate,

• the method comprising using a low pressure chemical vapor deposition (LP-CVD) system having a manifold capable of ultra-high vacuum (UHV) conditions to perform the steps of:
• a) heating said catalytic substrate at a growth temperature,
• b) exposing the catalytic substrate heated at said growth temperature to a gaseous atmosphere of a hydrocarbon-containing gas in said LP-CVD system, wherein the system is sealed to have an air leak rate of <1×10−7 sccm, thereby growing the graphene coating on the catalytic substrate, and
• c) cooling said catalytic substrate down to a temperature at which etching of the graphene coating by oxidizing species does not occur in said LP-CVD system, wherein the system is sealed to have an air leak rate of <1×10−7 sccm,
• wherein steps b) and c) are carried out in the gaseous atmosphere in which the ratio
• P
• ox
• P
• red
• is
• about 5×10−6 or less, Pox being the partial pressure of oxidizing species in the gaseous atmosphere and Pred being the partial pressure of reducing species in the atmosphere,
• wherein steps b) and c) are carried out in the gaseous atmosphere having a reduced content of oxidizing species and comprising about 100 ppb or less of oxidizing species,
• wherein steps b) and c) are purified before use so as to comprise about 100 ppb or less of oxidizing species, and
• wherein steps a), b) and c) are carried out in a reactor surrounded by heaters, said heaters providing the temperatures required for said steps a), b) and c).