Heinrich Zeininger

High current hybrid single walled carbon nanotube/graphene field emitters

Solution processed single walled carbon nanotube (CNT)/graphene hybrid samples are a low-cost alternative to chemical vapor deposition processed CNTs or graphene samples for field emission due to their fast and simple fabrication process. The electron field emission of this hybrid system was characterized regarding maximum current and long-term stability. The influence of measurement conditions such as chamber pressure, pulse-on time, and duty cycle on current–voltage characteristics was investigated. Furthermore, the anode size, anode geometry, and anode material were varied. The current density reached up to 2.9 A/cm2 when using a very small anode area of 0.8 mm2. A surface modification was observed after the emission with high current density. Very high maximum currents up to 400 mA in IV measurements and 90 mA in pulsed long-term stability measurements were achieved with thin hybrid layers of 1 μm.