Development of Dy3+-doped Gd2MoB2O9 phosphor and their luminescence behavior

In this work, the Gd2MoB2O9 and Gd2MoB2O9:Dy3+ phosphors have been prepared by solid state reaction and their structural and luminescence properties have been studied. The Gd2O3, MoO3, H3BO3 and Dy2O3 were used as starting materials and homogeneously mixed with appropriate ratio. The mixed materials were pressed at 20 tons and sintered at 800, 850, 900, 950, 1000, 1050 and 1100°C. The Gd2MoB2O9 phase was confirmed by X-ray diffractometer (XRD). The photoluminescence spectra measured by 257 nm excitation show one emission peak at 310 nm corresponding to 6P7/2→8S7/2 of Gd3+, and four emission peaks of Dy3+ at 478, 575, 663 and 754 nm corresponding to 4F9/2 → 6H15/2, 6H13/2, 6H11/2 and 6H9/2 transitions, respectively. The chromaticity coordinates under excitation of λex = 352 nm are (0.48, 0.42), which lies in the white region of CIE 1931 chromaticity diagram. The radioluminescence property was studied by 50 kV, 30 mA X-ray irradiation and compared with commercial BGO crystal. It was found that the i...