High Quantum Yield Gd4.67Si3O13:Eu3+ Red-Emitting Phosphor for Tunable White Light-Emitting Devices Driven by UV or Blue LED

Abstract

Eu3+-activated oxide components appear as a kind of rare-earth red phosphors that can be used for warm white light-emitting diode (LEDs). At present, it is still a challenge to synthesize oxide-component phosphors with high photoluminescence quantum yields compared to those of nitride and fluoride red phosphors. Herein, we propose a kind of Eu3+-activated Gd4.67Si3O13 rare-earth silicate phosphor by the convenient high-temperature solid reaction method. These designed phosphors can be effectively excited by either 394 nm near-ultraviolet light or 465 nm blue light and then emit red light at a dominant wavelength of 615 nm. Particularly, for the optimal Eu3+-concentration-activated Gd3.67EuSi3O13 phosphor, photoluminescence quantum yields are measured to be above 80%, which is superior to that of the general rare-earth oxide salt phosphor and comparable to that of commercial rare-earth nitride red phosphors such as Ca-α-SiAlON:Eu2+ (QY = 70.5%) and CaAlSiN3:Ce3+ (QY = 80%). Packaged with commercial yellow phosphor Ce3+:YAG and UV or blue LED chip, our red component serves to improve the CRI and CCT for the tunable white light-emitting devices. Moreover, the phosphor has good thermal cycling stability with a thermal-quenching activation energy of 0.28912 eV. Finally, the temperature-dependent properties make the Gd4.67Si3O13:Eu3+ phosphors have potential application in optical temperature measurement systems. The maximum relative sensitivity Sr is found to be 1.05 × 10–2 K–1 at 456 K.