Photoluminescence properties of A1(3)GdB(4)O(12): Eu phosphors

An investigation is reported of the photoluminescence (PL) properties of Al 3GdB4O12:Eu phosphors. Under vacuum ultraviolet excitation, Al3xGdB4O12:Eu exhibited a bright red luminescence with CLE chromaticity coordinates of (0 .643, 0.356) with a PL intensity of 60% of the sodium salicylate standard. The PL spectrum showed a ground state splitting pattern consistent with D-3 symmetry. The PL excitation spectrum showed sharp lines due to the S-8(7/2 )-I-6(J) and P-6(J) transitions of Gd3+ in addition to the f-f transitions of Eu3+. The charge transfer band of Eu was observed at 250 nm and the host absorption band was detected at 157 nm. Time-resolved spectroscopy was per formed to investigate the interaction between Gd and Eu ions. The energy tr ansfer rate from Gd to Eu ions was found to be 17 000 s(-1). (C) 2000 Elsev ier science S.A. All rights reserved.