Li Yanyan, Yin Yuan, Wang Tianli, Wu Junxiao, Zhang Jia, Yu Shuaishuai, Zhang Meiguang, Zhao Lei, Wang Wenjie
Collaborative Innovation Center of Rare-Earth Optical Functional Materials and Devices Development, School of Physics and Opto-Electronic Technology, Baoji University of Arts and Sciences, Baoji, Shaanxi 721016, P. R. China.
Dalton Trans. 2021 Mar 28;50(12):4159-4166. doi: 10.1039/d1dt00345c. Epub 2021 Mar 5.
There is an urgent need to develop phosphors with high quantum efficiencies (QEs) since white light-emitting diodes (WLEDs) have emerged as a new generation of illumination materials. Utilizing energy transfer to improve the absorption of activators and adjust the emission colors of samples is one effective strategy. Here, color-tunable phosphors of the form CaAlO:Ce,Tb were synthesized aiming at efficient energy transfer from Ce to Tb. Since Tb can be suitably sensitized by Ce, the co-doped phosphors can be effectively excited by near-ultraviolet (NUV) light. The internal QE of CaAlO:0.04Ce,0.04Tb under 350 nm excitation is as high as 92.55%, and the external QE is 71.02%. A WLED fabricated from BAM:Eu, CaAlO:0.04Ce,0.04Tb, and CaAlSiN:Eu with a 365 nm LED chip exhibited a correlated color temperature (CCT) of 4706 K and a color rendering index (CRI, R) of 81.44. The energy transfer mechanism and thermal stability of the phosphor were also investigated. The results provide an effective approach for developing highly efficient green-emitting phosphors for NUV WLEDs.
由于白光发光二极管（WLED）已成为新一代照明材料，因此迫切需要开发具有高量子效率（QE）的荧光粉。利用能量转移来提高激活剂的吸收并调整样品的发射颜色是一种有效的策略。在此，合成了CaAlO:Ce,Tb形式的颜色可调荧光粉，旨在实现从Ce到Tb的高效能量转移。由于Tb可以被Ce适当地敏化，因此共掺杂荧光粉可以被近紫外（NUV）光有效激发。CaAlO:0.04Ce,0.04Tb在350 nm激发下的内量子效率高达92.55%，外量子效率为71.02%。由BAM:Eu、CaAlO:0.04Ce,0.04Tb和CaAlSiN:Eu与365 nm LED芯片制成的WLED的相关色温（CCT）为4706 K，显色指数（CRI，R）为81.44。还研究了该荧光粉的能量转移机制和热稳定性。这些结果为开发用于NUV WLED的高效绿色发射荧光粉提供了一种有效方法。
