Heterogeneous chemiluminescence of crystalline phosphors in products of dissociation of sulfur dioxide

A luminescence has been revealed for the first time when SO is oxidized on the Y₂O₂S-Eu surface. Kinetic and spectral characteristics of heterogeneous chemiluminescence (HCL) have been studied. A model explaining the features of HCL has been proposed. In addition to reactions of adsorption, oxidation, and desorption, this model takes into consideration the reactions of the atomic-molecular exchange O + SO₂-L → SO-L + O₂ and dissociation SO₂-L + V_as → SO-L, where L is the lattice symbol, V_as is the vacancy coming to the surface by diffusion. A mechanism of heterogeneous chemiluminescence has been discussed. It comprises the energy transfer to the center of luminescence according to the reaction SO₂ ^e-L + Eu³⁺ → SO₂-L + (Eu³⁺)^e; (Eu³⁺)^e → Eu³⁺ + hv, where SO₂ ^e-L is the electron-excited SO₂-L molecule. The spectrum of HCL Y₂O₂S-Eu is linear being typical of intracenter transitions in the f-shell of Eu³⁺. The lines of CHL are broadened as compared to the lines of photoluminescence.