Electronic excitations induced by the impact of coinage metal ions and clusters on a rare gas matrix: Neutralization and luminescence

Low-energy collisions of atomic ions and cluster ions with rare gas covered metal substrates can lead to strong light emission which is element and size specific. Instead of a direct energy transfer into the electronic system of the cluster the observed emission originates from excitons trapped in the rare gas layer which carries the excitation energy. The nature of the processes involved in the neutralization and excitation of the neutral clusters electronic system are discussed. Strong analogies to thermoluminescence are found.