Development of zeolite-derived novel aluminosilicate phosphors

In this research, zeolite-derived aluminosilicate phosphors were synthesized through the ion exchange route. Red light-emitting property of Eu3+-doped aluminosilicate phosphors were discussed from a view point of the Eu content, heat-treatment condition and the oxidation state of Eu ions. The crystalline phase of the host aluminosilicates could be successfully controlled as designed based on the published NaAlO2–SiO2 binary phase diagram. Orange-red emission peaks derived from the 5D0→7Fj (j=0, 1, 2, 3, 4) transition of Eu3+ were observed around 590–700 nm, and 4f65d→4f7 transition of Eu2+ was observed at around 400–500 nm. The relative intensity I(5D0→7F2) of the dominant emission peak at 612 nm increased consistently with the Eu content. The results of the XANES spectroscopy analysis revealed that Eu2+ ion in the 1400 °C as heat-treated host aluminosilicate were successfully converted to Eu3+ by the additional annealing at 1100 °C. The Eu contents and heat-treatment conditions were determined to exhibit the best performance as a red phosphor, which were 10 wt% and 1500 °C, respectively