Desorption Induced by Electronic Transitions at Metal Surfaces.

Abstract

An attempt is made to provide a physical basis for DIET (desorption induced by electronic transitions) at metal surfaces. For this purpose, a theoretical description for DIET is given from a microscopic point of view. From the calculation for the dependence of the DIET probability on the penetration depth of the laser light and on the band-width of the electron system of the metal substrate, it is suggested that the spatial locality of electronic excitations affects the probability significantly. It is shown, furthermore, that the DIET probability increases, as the shape of PES (potential energy surface) is changed such that the number of adsorbate bound-states in the PES is decreased. As an order of magnitude, the result of calculation for the DIET probability of NO from Cu(111) agrees with the probability estimated experimentally.