Zero‐Concentration Quenching in Ce ³⁺ ‐Doped Ca ₂ Y ₈ (SiO ₄ ) ₆ O ₂ Phosphors: From Multifunctional Lighting to Plant Growth Promotion and Viral Resistance Attenuation

ABSTRACT Ce 3+ ‐doped Ca 2 Y 8 (SiO 4 ) 6 O 2 phosphors were designed to realize multifunctional lighting and plant viral resistance regulation. Here, to manipulate the concentration quenching effect of the resultant phosphors, the site substitution engineering, i.e., Ce 3+ occupies the different cationic sites in Ca 2 Y 8 (SiO 4 ) 6 O 2 host lattices, is adopted. Excited by near‐UV light, the synthesized phosphors can emit dazzling cyan emission, and its intensity is highly dependent on dopant content and occupation position. Specially, when Ce 3+ occupies the Ca 2+ site, the zero‐concentration quenching happens in the final products, of which its quantum efficiency is 44.9%. Via using the developed cyan‐emitting phosphors, two different devices, i.e., white light‐emitting diode (white‐LED) and cyan‐emitting LED, are packaged to reveal their feasibilities in multifunctional lighting. The plant growth experiments suggest that the growth and photosynthesis of plants can be promoted utilizing the cyan‐emitting LED as supplementary lighting. Furthermore, the cyan‐emitting LED can regulate the susceptibility of N. benthamiana to viral infection. Transcriptome analysis of the underlying mechanism shows weakened plant‐pathogen interaction and MAPK (Mitogen‐activated protein kinase) signaling pathway. Our findings do not only raise an efficient route to design zero‐concentration quenching luminescent materials but also clarify that the plant growth and defense trade‐off can be adjusted by cyan‐emitting light.