Ionization energies and structures of lithium doped silicon clusters†
Abstract
We report on a combined experimental and theoretical study of the ionization energies and structures of small lithium doped silicon clusters, SinLim with n = 5–11 and m = 3–6. Photoionization efficiency curves are measured in the 4.68–6.24 eV range and subsequently compared with calculated values of both vertical and adiabatic ionization energies for the lowest energy isomers obtained using density functional theory at the B3LYP/6-311+G(d) level. The evolution of the cluster geometries and ionization energies is studied as a function of the number of silicon and lithium atoms along the SinLi3 (n = 5–11) and Si8Lim (m = 1–6) series, respectively. For most studied sizes good agreement is found between the experimental and the calculated ionization energies for the lowest-energy isomer. In the SinLi3 (n = 5–11) series, positively charged lithium atoms surround a negatively charged silicon framework and mainly act as