Ejection of excimers from the surface of solid argon upon exciton self-trapping

The fate of an excimer (${\mathrm{Ar}}_2$*) formed upon exciton self-trapping is investigated by use of a classical dynamics calculation. It is shown that the triplet excimer, formed by trapping on the surface, may be ejected from the film without significant vibrational relaxation and with a kinetic energy less than 0.1 eV. This ejection is shown to be related to the formation of a "cavity" around an ${\mathrm{Ar}}_2$* located in the bulk of solid Ar. At a damaged surface site, vibrationally excited excimers may relax and remain weakly bound to the solid. Following emission of a photon, a ground-state atom is ejected with a kinetic energy of about 0.5 eV, as observed experimentally.