Simultaneous multi-wavelength ultraviolet excited single-phase white light emitting phosphor Ba1-x(Zr,Ti)Si3O9:xEu

A kind of novel compound Ba 1-x (Zr,Ti)Si 3 O 9 :xEu simultaneously activated by different-valence Eu 2+ and Eu 3+ ions has been successfully synthesized. The existence of Ti 4+ -O 2- charge transfer (CT) transitions in Ba 1-x ZrSi 3 O 9 :xEu is proved by the photoluminescence spectra and first principle calculations, and the Ti 4+ ions come from the impurities in commercial ZrO 2 raw materials. Under the excitation of multi-wavelength ultraviolet radiation (λ EX  = 392, 260, 180 nm), Ba 1-x ZrSi 3 O 9 :xEu (x = 0.15) can directly emit nearly white light. The coexistence of multiple luminescent centers and the energy transfer among Zr 4+ -O 2- CT state, Ti 4+ -O 2- CT state, Eu 2+ and Eu 3+ ions play important roles in the white light emission. Ba 1-x ZrSi 3 O 9 :xEu (x = 0.15) has good thermal stability, in particular, the intensity of emission spectrum (λ EX  = 392 nm) at 150 °C is ∼96% of that at room temperature. In general, the multi-wavelength ultraviolet-excited single-phase white light emitting phosphor Ba 1-x (Zr,Ti)Si 3 O 9 :xEu possesses a promise for applications in white light emitting diodes (WLEDs), agriculture, medicine and other photonic fields.