Synthesis and Photoluminescence Properties of a Novel Red-Emitting Na2Y2Ti3O10:Eu3+,Sm3+ Phosphor for White-Light-Emitting Diodes

A novel red-emitting Na2Y2Ti3O10:Eu3+,Sm3+ phosphor was synthesized for the first time, and its photoluminescence (PL) properties were investigated for application to white-light-emitting diodes (W-LEDs). The Na2Y1Eu1Ti3O10 phosphor showed a 3-fold higher PL intensity compared to that of a commercial red-emitting Y2O2S:Eu3+ phosphor under 396 nm irradiation. Sm3+ ions were introduced as a sensitizer, and they increased the PL intensity by up to 35% under 410 nm irradiation. The effects of introducing the sensitizer were investigated by measuring the quantum efficiencies and the time-resolved PL decay curves. The Na2Y1Eu1Ti3O10 phosphor exhibited remarkable resistance to thermal quenching, and a W-LED comprising the phosphor showed bright white emission with a color rendering index (R a) of 83, a color temperature of 5556 K, and Commission Internationale de I’Eclairage (CIE) color coordinates of (0.3306, 0.3754).