Uniform graphene on liquid metal by chemical vapour deposition at reduced temperature

Liquid metal, such as Ga, has been demonstrated to be a good catalyst to grow uniform graphene at about 1000 °C. However, at reduced temperature, the high surface tension of Ga causes the limited spreading-ability over the supporting substrate, which prevents the formation of large-area graphene. Here we present that the addition of Cu could efficiently decrease the surface tension of Ga, thus achieving a larger coverage. We succeeded in growing large-area, uniform and single-layer graphene at 800 °C by atmospheric chemical vapour deposition using CH4 as the carbon source.