Field emission from flat graphene sheets is a challenge due to fewer emission sites. Here, we have synthesized free‐standing vertically oriented few‐layer graphene (FLG) films directly on dielectric substrates by hot‐filament chemical vapor deposition (HFCVD) without any catalyst or special substrate treatment. The fabricated FLGs with a large smooth surface topography, standing roughly vertical to the substrate are found to grow according to the Stranski–Krastanov growth mechanism. The ease of large‐area preparation and the low turn‐on field of 22 V µm−1 in addition to the large field enhancement factor of ≈6520 for electron field emission suggest that the vertically oriented FLGs could be used as a potential edge emitter.
Scanning electron microscopy image of vertically oriented few‐layer graphene on a SiO2/Si substrate with the schematic of field electron emission.