Graphene Films Grown on Insulating Substrates

We report a method of direct CVD growth of carbon films on quartz substrates. The films are grown at temperatures from 650 to 1200 $^{\circ}$C in a graphite container filled with methane. Films grown at 1200 $^{\circ}$C reveal clear G and 2D Raman bands characteristic of graphene. A combination of Raman, absorption and electrical measurements allows us to conclude that carbon films grown by this method are polycrystalline graphene, large areas of which may be composed of single carbon layer. Sheet resistivity of these graphene films is low enough to make them interesting objects for electronic applications. Advantages of our synthetic approach include simplicity and the ability to deposit films on any insulating substrate, which can stand temperature of at least 650 $^{\circ}$C. Thus far, no factors limiting the area of deposition and uniformity of the deposited graphene films have been identified.