Highly Efficient Ultrafast Energy Transfer into Molecules at Surface Step Sites

Autor: H. G. Backus, Ellen, Forsblom, Mattias, Persson, Mats, Bonn, Mischa
Zdroj: The Journal of Physical Chemistry - Part C; May 2007, Vol. 111 Issue: 17 p6149-6153, 5p
Abstrakt: Ultrafast laser-induced desorption of NO and CO molecules on a platinum surface reveals that the rate of energy transfer between the laser-heated electrons and the adsorbate depends critically on the precise adsorbate location. An analysis based on a simple electronic friction model suggests that this femtosecond energy transfer occurs ∼3 times faster to adsorbates at step sites compared to adsorbates located on atomically flat surface regions. Density functional theory calculations of vibrational damping rates by electron−hole pair excitations corroborate the increased rate of energy transfer at step sites and show that it is caused primarily by an increased local density of adsorbate-induced states around the Fermi level.
Databáze: Supplemental Index