Formation of S2- and Se2- molecular ions through photochemical reactions and their vibronic luminescence in KCl:MnS/Se crystals

It is found that when quenched KCl:MnS/Se crystals are irradiated with UV light, S-2(-) and Se-2(-) molecular ions are formed. By this method these molecular ions were effectively introduced into KCI lattice for the first time. At 8.8 K, such luminescence spectra consist of one or more vibronic series of zero-phonon lines associated with isotope structure and phonon-side bands. The spectroscopic constants v(00), omega(0)(") and omega(0)(")chi(0)(") were calculated for the ground state of Se-2(-) ions. On the other hand, from the detailed observation of photochemical reactions in KCl : MnS, it was found that Mn+, Mn-0 and F centers were produced following the formation of S-2(-). From above results, a model for the formation of S-2(-) was proposed. (C) 2000 Elsevier Science B.V. All rights reserved.