LUMINESCENT PROPERTIES OF ZnS SINGLE CRYSTAL ANNEALED IN THE V th GROUP ELEMENTS MELT

Abstract

The influence of ZnS single crystal annealing in the media based on V-group elements Bi and Sb on its photoluminescent (PL) properties was studied. The following media: Bi, Sb, Bi+Zn, Sb+Zn, Bi+S, Sb+As and Bi+Al were used for the annealing.Two types of the starting crystals were used: I) low resistivity ZnS; II) high resistivity ZnS. The annealing was carried out in the vacuumed silica ampoules at the temperatures of 1400 K (I) and 1200 K (II) during 100hrs. The obtained results show that ZnS crystals annealing in Bi and Sb melts leads to the analogical reorganization of radiation centers based on the native and impurity defects generated by interphase interaction at ZnS-melt interface. These defects are responsible for the appearance of the green radiation having the feature of intracentred transitions. The high value of green band half-width indicates that it is a superposition of a few bands. These could be a PL bands related to the oxygen presence, the impurity centers of the V group elements and to V S .