Formation of S-2(-) and Se-2(-) 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 l ight, S-2(-) and Se-2(-) molecular ions are formed. By this method these mo lecular ions were effectively introduced into KCI lattice for the first tim e. At 8.8 K, such luminescence spectra consist of one or more vibronic seri es of zero-phonon lines associated with isotope structure and phonon-side b ands. 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 formatio n of S-2(-). From above results, a model for the formation of S-2(-) was pr oposed. (C) 2000 Elsevier Science B.V. All rights reserved.