Lowering of work function induced by deposition of ultra-thin rubidium fluoride layer on polycrystalline diamond surface

Ultra-thin rubidium fluoride (RbF) was thermally evaporated onto polycrystalline diamond surface. The role of RbF as a strong dipole layer to lower the surface work function was investigated using ultraviolet photoemission spectroscopy, Kelvin probe and Auger electron spectroscopy. It was found that deposition of sub-monolayer of RbF could greatly reduce the work function of the diamond surface. Also, the ultra-thin RbF overlayer is very sensitive to electron irradiation. The electron irradiation can seriously weaken the effect of RbF as a surface dipole. (C) 1999 Elsevier Science B.V. All rights reserved.