Novel Cr<sup>3+</sup>‐Doped Garnet Phosphor with Broadband Efficient Far‐Red Emission for Photochrome Matching Plant‐Lighting
Xiangyi Dai, Xikun Zou, Haoran Zhang, Weibin Chen, Chaowei Yang, Мaxim S. Моlokeev, Zhiguo Xia, Yingliang Liu, Xuejie Zhang, Mingtao Zheng, Bingfu Lei
Abstract
Abstract Cr 3+ ‐doped phosphors are highly recognized in various fields for their remarkable luminous efficiency and spectral flexibility, including modern agriculture and horticulture. However, the shortage of suitable Cr 3+ ‐doped phosphors for far‐red LED devices has inhibited their popularization in plant lighting. Herein, an innovative Cr 3+ ‐doped phosphor Ca 2 YAl 3 Ge 2 O 12 :Cr 3+ (CYAG:Cr 3+ ), achieving a broad far‐red emission at 770 nm upon 450 nm blue light excitation is designed. The optimal CYAG:Cr 3+ phosphor exhibits a high internal quantum yield of 78.2% and low thermal‐quenching behavior of 85%@373 K. Thus, the fabricated phosphor‐converted LEDs (pc‐LEDs) for plant far‐red lighting have a high output power of 33.3 mW and photovoltaic conversion efficiency of 11.5% at 100 mA. The potential of CYAG:Cr 3+ in plant lighting is assessed by supplementing the far‐red lighting of Italian lettuce with fabricated pc‐LEDs, and the biomass of Italian lettuce is significantly increased by 33%. The successful development of CYAG:Cr 3+ phosphors provides a high‐quality option for plant far‐red light devices and further stimulates the development of new Cr 3+ ‐doped plant‐lighting phosphors.