Improved field emission from tungsten doped reduced graphene oxide

The emission capability of as prepared reduced graphene oxide (rGO) and tungsten doped reduced graphene oxide (W-rGO) film field emitter (FE) cathodes are investigated experimentally. It is observed that W-rGO films showed a highest emission current density of ∼ 800 A/cm
²
at an applied DC electric field of 6.6 V/μm, which is far superior than the current density of ∼ 390 A/cm
²
from an as prepared rGO film. Short stability test also showed that emission current is much more stable than the rGO films. These excellent improvements can be attributed to the doping of tungsten into the rGO film, which helped to repair the broken bonds thus lowering the turn on field. Also, tungsten gives the film an excellent mechanical stability and higher thermal load handling capability, which is very important to achieve a stable, high performance operation and long life.