The work function, field emission property (turn-on field), and Auger electron spectroscopy of cesiated carbon films on Si (100) have been investigated for codeposition of Cs neutral andC−ion beams at different energies (25–150 eV). The higher energy (150 eV)C−ion beam produces the lower work function surface (1.1 eV) as well assp3rich carbon film. The work function depends both on cesium concentration as well as on thesp3fraction in the carbon films. The turn-on field of the film can be as low as 7 V/&mgr;m. The thermal stability of the low work function surface has been investigated for postdeposition annealing up to 600 °C. An extremely high stability cold cathode has been made by forming cesium carbide. ©1997 American Institute of Physics.