A model of normal transfer of electrons on CO+K/Cu(111) surface

Co-adsorption of CO and Potassium on Cu(111) surface was investigated using a Kelvin probe. We found that CO can adsorb on the potassium pre-covered Cu(111) surface at room temperature. When θK<θmin (θmin=0.18), the adsorption of CO makes the work function increase. When θK>θmin, the work function first decreases and then increases with CO exposure. the results can be well accounted for by jellium-slab model [R.Q. Wu, K.L. Chen, D.S. Wang, Phys. Rev. B 38 (1988) 3180]. A Model of normal transfer of electrons is proposed for the co-adsorption of CO and potassium on the Cu(111) surface.