Investigations on Luminescent Properties and Energy Transfer for Activated Borophosphate Glasses and Glass Ceramics with Single- and Tri-Doping of Tm3+, Tb3+, and Sm3+

Abstract

Tm3+/Tb3+/Sm3+ single- and tri-doped borophosphate glasses (BaO-ZnO-P2O5-B2O3) and Tm3+/Tb3+/Sm3+ tri-doped BaZn2(PO4)2 glass ceramics were successfully prepared, achieving white light emission. The samples’ emission spectra and time-resolved fluorescence decay curves confirmed the efficient energy transfer processes from Tm3+ to Sm3+ and Tb3+ to Sm3+, which optimizes the material's luminescent colors. By adjusting the Sm3+ doping concentration, the chromaticity coordinates of the samples changed from (0.2376, 0.2631) to (0.3108,0.3325). Heat treatment induced the precipitation of BaZn2(PO4)2 crystals in the glass matrix. The sample with 90 minutes heat treatment has the chromaticity coordinate (0.3248,0.3483) and the correlated color temperature (5830K), which are very close to the standard white light (0.3333,0.3333, and 5454K). After the crystallization of 90-minute durations, the band gap decreased from 3.35 eV to 3.22 eV and the photoluminescence quantum yield (PLQY) increased from 19.37% to 22.72%. The results indicate that Tm3+/Tb3+/Sm3+ tri-doped glass-ceramics could be a suitable candidate material for white light-emitting diodes.

Keywords: Glass-ceramics, Rare Earths, photoluminescence, energy transfer, Optical band gap, Photoluminescence quantum yield