The Luminescence of Zinc Sulfide Activated by Lead

Abstract

Zinc sulfide activated by lead shows fluorescence in various bands, two of which can be attributed to lead. The first band has a maximum at 4850A, the second one at 6100A. The orange band is favored by sulfurizing conditions and appears irrespective of whether halide ions are present or not. This band is attributed to a characteristic electronic transition in divalent lead ions, occupying normal lattice sites. The green band is favored by reducing conditions and only appears when chlorine ions are present. This band is attributed to electron transfer transitions between positive and negative ions of configurations formed by monovalent lead and chlorine ions, situated at normal lattice sites, together with the neighboring lattice ions. A green band appearing in reduced zinc sulfide is attributed to a stoichiometric excess of zinc.