Study on the stable and efficient white-emitting Bi/Tb/Eu tridoped single-phase borate Sr3YB3O9 phosphors

Several series of novel broad band white light emitting Bi/Tb/Eu tridoped in multiple lattice sites of single-phase Sr3YB3O9 (SYBO) borate phosphors, which covered almost all visible range through mixing the separate blue, green and red emissions from dopants of Bi, Tb and Eu, respectively, were successfully obtained by using the facile and conventional solid-state reaction method under air condition. Rietveld refinements based on XRD data together with the combination match of charge and ion radius for dopants of Bi, Tb, Eu and lattice cations of Sr, Y and B show that Bi is more inclined to replace the Sr site while Tb/Eu are more likely to enter the Y site, respectively. Through spectrum analysis of photoluminescence excitation (PLE), PL and decay lifetime, the efficient energy transfer (ET) from the Bi to both Tb and Eu, and from Tb to Eu are all testified via the dipole-dipole interactions, indicating that the non-rare-earth activator Bi is acting both as the blue luminescence cen-ter and ET sensitizer, while the Tb contributes both as ET bridge and green luminescence center to better connect the Bi and Eu. The optimal tridoped white emission SYBO phosphor appears good thermal stability, which could continue to have its PL intensity above 75% at 150 degrees C as compared with the original room temperature PL in-tensity. Altogether, the single-component SYBO:Bi/Tb/Eu phosphor could be well served as potential white light phosphor for n-UV pumped wLED devices.