Mechanism of electron field emission from diamond and diamond-like carbon

Various types of carbon films such as diamond-like carbon are being intensively developed for use as flat film microcathodes for Field Emission displays. The original motivation for this work was the discovery that diamond surfaces can have a negative electron affinity (NEA), so there would be in principle no barrier for the emission of electrons from its conduction band into the vacuum. However, relatively easy field emission has now been observed in many carbon-based materials-diamond, nano-crystalline diamond, diamond-like carbon (DLC) and carbon nanotubes-suggesting that NEA is not essential and more general mechanisms might apply.