High Quantum Yield Gd<sub>4.67</sub>Si<sub>3</sub>O<sub>13</sub>:Eu<sup>3+</sup> Red-Emitting Phosphor for Tunable White Light-Emitting Devices Driven by UV or Blue LED
Wanggui Ye, Chong Zhao, Xiaofei Shen, Chaoyang Ma, Zhonghua Deng, Yanbin Li, Yuzhen Wang, Chuandong Zuo, Zicheng Wen, Yingkui Li, Xuanyi Yuan, Chong Wang, Yongge Cao
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.