Growth of large sp2 domain size single and multi-layer graphene films at low substrate temperature using hot filament chemical vapor deposition

• Single, bi and a few layer graphene films are grown on Ni foil using HFCVD at a 700 °C.
• The D band is almost absent in the Raman spectra indicating defect free films of high quality.
• Average crystallite size of sp2 domains is 117 nm for single layer and 380 nm for bilayer graphene films.· Deposited films have little variation in number of graphene layers (1-6) over a sample size of 1cmC1cm.
• This relatively more uniform growth of graphene is useful for the fabrication of graphene based devices.

Single, bi and a few layer graphene films of large sp2 domain size were grown on Ni foil using hot filament chemical vapor deposition at a relatively low substrate temperature of 700 °C. The number of layers was found to vary from 1 to 6 and 7 to 12 for the films deposited at a process pressure of 1.5 mbar for the deposition time of 30 and 20 min, respectively. Further at a lower process pressure of 1 mbar, 2–8 layers were obtained for 10 min deposition time. The measured average sp2 domains size was found to be in the range of 117–279 nm in the case of 1–6 layers of graphene films. These large domain size graphene films could be very useful for graphene based electronic devices and other applications.