A novel tunable white light emitting multiphase phosphor obtained from Ba2TiP2O9 by introducing Eu3+

Tunable white light was realized in samples Ba2(1−x)TiP2O9:2xEu (x = 0–0.80) by introducing orange-red light emitting Eu3+ in self-activated blue-green light emitting matrix Ba2TiP2O9. The sample Ba2(1−x)TiP2O9:2xEu is a multiphase system consisting of Ba2TiP2O9, EuPO4 and TiO2 when x is greater than or equal to 0.20. The tunable light from blue-green to bluish-white, to white, and eventually to pinky-white of samples Ba2(1−x)TiP2O9:2xEu under UV light excitation is attributed to the light mixture of tunable blue-green light from Ti4+–O2− charge transfer transition in Ba2TiP2O9 and orange-red light from Eu3+ 4f–4f transition mostly in EuPO4. The Commission International de l’Eclairage chromaticity coordinates, correlated color temperature and color rendering index were tuned from (0.262, 0.339), 9492 K and 74 for matrix sample Ba2TiP2O9 to (0.324, 0.346), 5876 K and 87 for sample Ba2(1−x)TiP2O9:2xEu (x = 0.40) under UV light excitation. Therefore, a kind of promising UV-excited white light emitting multiphase phosphor was obtained.