The photo-, electro-, and cathodoluminescence spectra of ZnS:Mn2+ crystals were studied, and the defect density in the crystals was evaluated by decorating freshly cleaved surfaces with anthraquinone. The results were used to assess the site symmetry around the Mn centers responsible for the emissions at 557, 578 and 600nm.

Defect Structure and Luminescence Behavior of ZnS:Mn2+ Crystals. M.F.Bulanyi, V.I.Klimenko, A.V.Kovalenko, B.A.Polezhaev: Inorganic Materials, 2003, 39[5], 436-40