Spectroscopy and Photophysics of O2 in the Neighborhood of the Dissociation Limit in Rare Gas Solids

Abstract

Abstract The energy levels, potentials and relaxation mechanism of O2 doped in rare gas (Ar, Kr) and N2 solids in the neighborhood of the dissociation limit have been studied by means of absorption and emission spectroscopy. The environmental effects of the solids on the energy level shift are not large, but the cage effect is important in considering the relaxation mechanism following the laser irradiation. The efficient cross-relaxation among nested Herzberg states and specific energy transfer dependent on the energy gap between relevant levels, in particular from A′ state to c state, have been found. Due to the very slow vibrational relaxation, vibrationally excited O2 molecules have been accumulated to a high concentration in the solid. Based on the B–X transition energy values from the vibrationally excited O2 molecules, the B state potential curve has been determined. This shows that the cage effect retards the atomic dissociation in the B state.