Chen Xiaoyuan, Huang Xiaoyong
College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, People's Republic of China.
ACS Appl Mater Interfaces. 2024 Oct 23;16(42):57365-57376. doi: 10.1021/acsami.4c12244. Epub 2024 Oct 12.
Efficient blue-light-excitable broadband cyan-emitting phosphors may yield full-visible-spectrum white light-emitting diodes (WLEDs) with ultrahigh color rendering (Ra > 95). However, this requires closing the "cyan gap" in the 480-520 nm region of the visible spectrum, which is challenging. Herein, a well-performed cyan-emitting garnet phosphor CaLuAlGaSiO:Ce (CLAGSO:Ce) is reported. Under 430 nm excitation, the optimal CLAGSO:5%Ce compound exhibits a broadband cyan emission (peak, 496 nm; bandwidth, 102 nm) with a high internal quantum efficiency of 85.6% and an excellent thermal resistance performance (69.1% at 423 K). Importantly, this as-prepared cyan-emitting phosphor provides sufficient cyan emission and enables filling the well-known so-called "cyan gap" between the blue LED chip and the commercial YAlO:Ce (YAG:Ce) yellow phosphor. Impressively, a WLED device fabricated with the optimal CLAGSO:5%Ce sample shows a low correlated color temperature (4053 K) and an ultrahigh color rendering index (Ra = 96.6), as well as an excellent luminous efficacy (74.09 lm W). These results highlight the importance of blue-excited broadband cyan-emitting phosphors in closing the cyan gap and enabling human-centric full-visible-spectrum warm WLED devices for high-quality solid-state lighting.
高效的蓝光激发宽带发射青色磷光体可产生具有超高显色性（Ra>95）的全可见光谱白色发光二极管（WLED）。然而，这需要填补可见光谱480-520nm区域的“青色间隙”，这具有挑战性。在此，报道了一种性能良好的发射青色的石榴石磷光体CaLuAlGaSiO:Ce（CLAGSO:Ce）。在430nm激发下，最佳的CLAGSO:5%Ce化合物呈现宽带青色发射（峰值496nm；带宽102nm），具有85.6%的高内量子效率和优异的耐热性能（423K时为69.1%）。重要的是，这种制备的发射青色的磷光体提供了足够的青色发射，并能够填补蓝色LED芯片与商用YAlO:Ce（YAG:Ce）黄色磷光体之间众所周知的所谓“青色间隙”。令人印象深刻的是，用最佳的CLAGSO:5%Ce样品制造的WLED器件显示出低相关色温（4053K）和超高显色指数（Ra=96.6），以及优异的发光效率（74.09lm/W）。这些结果突出了蓝色激发宽带发射青色磷光体在填补青色间隙以及实现以人类为中心的全可见光谱暖WLED器件用于高质量固态照明方面的重要性。
