IR Photoluminescence of the RbBa2(PO3)5 Polyphosphate Containing Bi+ Impurity Centers

— The rubidium barium polyphosphate RbBa 2 (PO 3 ) 5 containing impurity bismuth monocations has been prepared via crystallization from a melt with the stoichiometric composition and melts containing excess of rubidium or barium. The samples thus obtained demonstrate broadband photoluminescence in the Near-IR. Analysis of their photoluminescence properties leads us to conclude that they contain two types of emission centers and that predominant formation of one of them depends on melt composition. Our results show that one of the emissive centers is a bismuth monocation substituting for a barium cation and that it forms mainly from barium-deficient melts. The other emissive center, a Bi + monocation substituting on the rubidium site, results predominantly from crystallization of rubidium-deficient melts.