Transfer‐Free Growth of Few‐Layer Graphene by Self‐Assembled Monolayers

Graphene is an ideal 2D planar structure with an electron mobility that reaches 200 000 cm 2 V − 1 s − 1 , an ideal theoretical sheet resistance of 30 Ω sq − 1 , and an excellent transmittance of 97.5% per layer. [ 1–3 ] Recent development of large area graphene synthesis on a metal layer by chemical vapor deposition opened the possibility for a wide range of applications. [ 4–8 ] Although a Ni metal layer provided an effi cient way of producing graphene, controlling the number of layers has not been realized and the graphene layers are not uniform. [ 4–6 ] Cu foil has been used to produce monolayer graphene by the self-limiting growth but controlling the number of graphene layers has never been accessible. [ 8 ] However, controlling the number of graphene layers with high uniformity is a prerequisite for numerous applications. For instance, the bandgap is opened in bilayer graphene, which is useful for transistors. [ 9 ] Furthermore, these growth methods on a metal layer involve an inevitable transfer step of large area graphene that creates defects, impurities, wrinkles, and cracks and has been a bottleneck for science and technology innovation. [ 10 ]