Luminescence of nitrogen and N2–Ar solid solution cryocrystals in the vacuum ultraviolet region
Abstract
Luminescence spectra of the wlΔu and a′Σu− singlet electronic excitations were investigated in the condensed a phase of nitrogen and a N2–Ar solid solution. Vibronic relaxation of the w state is slowed due to weak interaction with acoustic lattice vibrations. A rapid release of the energy of the electronic excitation a 1Πg to the lowest state a′1Σu− is observed. The localized-exciton model was confirmed to be applicable to luminescence spectra of singlet excitons in α -nitrogen crystals. There is an anomalous intensification of the absorption bands of the w–X system in irradiated N2-Ar cryocrystals due to abrupt lowering of the substitution-site symmetry in the argon matrix and to a strong admixture of the b 1Πu state.