Field emission properties of diamond-like carbon films annealed at different temperatures

Effect of annealing on the field emission properties of diamond-like carbon (DLC) films deposited by high power excime laser technique was studied. Raman spectrometry and X-ray photoelectron spectrometry (XPS) were used to determine the chemical bonding structural change of the annealed DLC films. It was found that the annealing transformed gradually DLC films into a graphitic structure as annealing temperature was increased to more than 600 °C, simultaneously field emission properties of DLC films were enhanced markedly. Graphitization of DLC films induced by annealing caused the formation of a large fraction of sp2 C in the DLC films, which played an important role in the enhancement of field emission properties for DLC films. Rich sp2 C cluster acted as a conduction part in the films could increase the conductivity of DLC films and lower the effective work function of DLC films, consequently improve field emission properties of DLC films.