A method to grow multi layers graphene (MLG) just by thermal annealing in an inert atmosphere is reported. A molybdenum (Mo) catalyst layer is used in combination with a solid amorphous carbon (a-C) source on top or below the Mo layer. The formation of MLG directly on top of the catalyst substrate surface is confirmed by Raman spectroscopy, atomic force microscopy, cross-section transmission electron microscopy, electron energy loss spectroscopy and x-ray photoelectron spectroscopy. Growth of MLG on top of the Mo catalyst is demonstrated both with a-C below and above the Mo layer. The growth mechanism is attributed to the diffusion of a-C through the Mo layer and precipitation into the graphene at the surface, similar to the growth by chemical vapour deposition (CVD) on a Ni catalyst. The role of the inert Ar/H 2 atmosphere, carbon thickness, catalyst thickness, anneal time and anneal temperature are reported. Fast growth of MLG (5 min) at 915 °C is demonstrated. The quality of MLG prepared by thermal annealing is at least as good as that of MLG synthesized by CVD. The relevant achievements presented in this study make the proposed technique a promising alternative to CVD based MLG. @en

In this paper we report a novel transfer-free graphene fabrication process, which does not damage the graphene layer. Uniform graphene layers on 4" silicon wafers were deposited by chemical vapor deposition using the CMOS compatible Mo catalyst. Removal of the Mo layer after graphene deposition results in a transfer-free and controlled placement of the graphene on the underlying SiO2. Moreover, pre-patterning the Mo layer allows customizable graphene geometries to be directly obtained, something that has never been achieved before. This process is extremely suitable for the large-scale fabrication of MEMS/NEMS sensors, especially those benefitting from specific properties of graphene, such as gas sensing.@en

In this work we present the effect of defects in graphene on its potential for application in flexible electronics. We visualize defects at the grain boundaries, transfer defects and local atomic defects. We show that these defects are currently determining the gas barrier properties of graphene. Under strain up to only 2% we show that these defects lead to cracks in the graphene thereby deteriorating its conductivity.@en

In this work we present the effect of defects in graphene on its potential for application in flexible electronics. We visualize defects at the grain boundaries, transfer defects and local atomic defects. We show that these defects are currently determining the gas barrier properties of graphene. Under strain up to only 2% we show that these defects lead to cracks in the graphene thereby deteriorating its conductivity.@en