Enhanced luminescence of oxygen atoms and nitrogen molecules in nitrogen–krypton nanoclusters

We studied luminescence accompanied by an injection of nitrogen–krypton–helium gas mixtures after passing radiofrequency discharge into dense cold helium gas. In the cold helium gas N2–Kr nanoclusters were formed, with a core of Kr atoms and N2 molecules on the surface. Atomic nitrogen and oxygen resided in the N2 surface layers. When the temperature in the observation zone was in the range of 20–36 K, we observed enhanced emission of oxygen atom β-group and molecular nitrogen Vegard–Kaplan bands from N2–Kr nanoclusters. At these temperatures, nitrogen atoms efficiently recombine on the surface of nanoclusters with the formation of exited nitrogen molecules, leading to enhanced emission of Vegard–Kaplan bands. Simultaneously, the energy transfer from exited nitrogen molecules to the oxygen atoms enhanced O atom β-group emission.