Remote plasma-assisted low-temperature large-area graphene synthesis

Graphene is typically grown using thermal chemical vapor deposition (CVD) on metallic substrates such as copper and nickel at elevated temperatures above 1000 °C. The synthesis of large-area graphene at low temperature is highly desirable for large volume industrial production. In this paper, the authors report a remote plasma-assisted CVD graphene synthesis at a reduced temperature of 600 °C in a relatively shorter duration of 15 min. Scanning electron microscopy reveals the formation of large graphene crystal with an approximate size of 100 × 100 μm² over the entire 2 × 10 cm² surface of copper foil substrates. Raman spectra recorded for graphene grown at 600 °C show the presence of a graphene characteristic “2D” peak, attesting to the formation of graphene. The results show that it is possible to grow horizontal graphene at low temperatures and transfer it to flexible polyethylene terephthalate substrates. The utility of the synthesized graphene is ascertained through the successful fabrication of a flexible graphene-based electrochemical sensor for the detection of glucose concentration. The present research will have a direct impact on flexible wearable biosensors.