Below Band Gap Formation of Solvated Electrons in Neutral Water Clusters?

Abstract

Below band gap formation of solvated electrons in neutral water clusters using pump-probe photoelectron imaging is compared with recent data for liquid water and with above band gap excitation studies in the liquid and clusters. Similar relaxation times in the order of 200 fs and 1-2 ps are retrieved for below and above band gap excitation, in both clusters and liquid. The relaxation times independence from the generation process indicates that these times are dominated by the solvent response, which is significantly slower than the different solvated electron formation processes. The analysis of the temporal evolution of the vertical electron binding energy and the electron binding energy at half maximum suggests a dependence of the solvation time on the binding energy.