Comparative study of thermo-stimulated luminescence and electron emission of nitrogen nanoclusters and films

We have studied thermo-stimulated luminenscence and electron emission of nitrogen films and nanoclusters containing free radicals of atomic nitrogen. Thermo-stimulated electron emission from N2 nanoclusters was observed for the first time. Thermo-stimulated luminescence spectra obtained during the destruction of a N2–He sample are similar to those detected from N2 films pre-irradiated by an electron beam. This similarity reveals common mechanisms of energy transfer and relaxation. The correlation of luminescence intensity and electron current in both systems points to the important role of ionic species in relaxation cascades. Sublimation of solid helium shells isolating nitrogen nanoclusters is a trigger for the initiation of thermo-stimulated luminescence and electron emission in these nitrogen–helium condensates.