Role of H3BO3 and Sr2+/K+ in the luminescent property of NaBaB9O15:Eu2+

Abstract A series of Na1-zKzBa1-ySryB9O15:Eu2+ were synthesized by the high temperature solid state method. H3BO3 excess makes it easier for Eu2+ to enter Na+ site, and the single-phase "blue + green" double emission band can be observed, which is proved by thermoluminescence and the change of crystal structure. Moreover, there exists an intense energy transfer from the blue-emitting center to the green-emitting center, which is proved by the decay curve. The occupation of Eu2+ can be tuned by the introduction of Sr2+ and K+ in NaBaB9O15. Further, the highly thermal-sensitive property of NaBaB9O15: 1%Eu2+ makes it feasible for its potential application in luminescent ratiometric thermometers with wide temperature range. In addition, the disorder degree of matrix cations increases with the incorporation of K+, which improves the thermal stability.