Photoluminescence properties of Al3GdB4O12:Eu phosphors

An investigation is reported of the photoluminescence (PL) properties of Al3GdB4O12:Eu phosphors. Under vacuum ultraviolet excitation, Al3GdB4O12:Eu exhibited a bright red luminescence with CIE 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 D3 symmetry. The PL excitation spectrum showed sharp lines due to the 8S7/2–6IJ and 6PJ 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 performed to investigate the interaction between Gd and Eu ions. The energy transfer rate from Gd to Eu ions was found to be 17 000 s−1.