High efficiency near-infrared emission from Fe3+-doped NaAl11O17 phosphors for plant lighting

https://doi.org/10.1016/j.jallcom.2025.184900

Near-infrared (NIR) emitting phosphor-converted LEDs (pc-LEDs) have garnered significant interest due to their promising applications in diverse fields utilizing NIR spectroscopy. Fe³⁺ ions, as promising NIR activators, possess the advantages of being nontoxic and cost-effective, making them ideal candidates for NIR emission. In this work, NaAl_11-xO₁₇: xFe³⁺ phosphors were successfully synthesized, exhibiting a broad NIR emission band ranging from 650 to 850 nm, with the peak emission centered at approximately 770 nm. The phosphors demonstrate a high external quantum efficiency (EQE = 54.01 %) and excellent thermal stability. Distinct emission profiles were observed under three different excitation wavelengths, and four luminescent sites were discussed through low-temperature emission spectra. Furthermore, the electroluminescence (EL) spectrum of the fabricated pc-LEDs shows a strong spectral overlap with the absorption band of phytochrome P_fr, highlighting their great potential for plant lighting applications.