Substrate-assisted nucleation of ultra-thin dielectric layers on   graphene by atomic layer deposition
  We report on a large improvement in the wetting of Al2O3 thin films grown by un-seeded atomic layer deposition on monolayer graphene, without creating point defects. This enhanced wetting is achieved by greatly increasing the nucleation density through the use of polar traps induced on the graphene surface by an underlying metallic substrate. The resulting Al2O3/graphene stack is then transferred to SiO2 by standard methods. 
Bruno Dlubak, Piran R. Kidambi, Robert S. Weatherup, Stephan Hofmann,   John Robertson
cond-mat.mtrl-sci