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 D-5(o) -> F-7(j) (j = 0, 1, 2, 3, 4) transition of Eu3+ were observed around 590-700 nm, and 4f(6)5d -> 4f(7) transition of Eu2+ was observed at around 400-500 nm. The relative intensity I(D-5(o) -> F-7(2)) 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 degrees C as heat-treated host aluminosilicate were successfully converted to Eu3+ by the additional annealing at 1100 degrees 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 degrees C, respectively (C) 2012 Elsevier B.V. All rights reserved.