Near-Infrared Excited Mn4+- and Nd3+-Doped Y2SiO5 Luminescent Material with Flower-like Morphology for Plant-Centric Lighting Applications

Confronted with increasing global food demands, diminishing arable land, and climate volatility, controlled-environment agriculture with advanced red and far-red LED lighting can enhance photosynthesis and optimize plant growth. This investigation reports the generation of a Mn⁴⁺/Nd³⁺ co-doped Y₂SiO₅ phosphor with a Nd³⁺ concentration ranging from 0.1 to 2.5 mol% via a solid-state synthesis method, aiming to enhance red and far-red emission for plant cultivation LEDs. For the Y₂SiO₅:Mn⁴⁺ (1 mol%), Nd³⁺ (2 mol%) phosphor, the phase integrity, nanostructured morphology, elemental mapping, and vibrational characteristics were examined using XRD, Rietveld analysis, FTIR, SEM, and EDX. Nd³⁺ ions act as near-infrared excitation mediators, ensuring efficient Nd³⁺ → Mn⁴⁺ energy transfer upon 808 nm excitation, and this leads to pronounced red photoluminescence from Mn⁴⁺ ions that covers the range of 640-710 nm, exhibiting strong emission peaks centered at 650nm, 663nm, and 685nm, coinciding with the absorption band of phytochromes and chlorophyll. The optimal emission intensity was accomplished for a Nd³⁺ doping concentration of 2 mol%, beyond which concentration quenching occurred. The material produced a strong, concentrated deep red emission with CIE coordinates near (0.73, 0.27) and a high color purity of 98.96%, making it well-suited for photosynthetic activation. A phosphor-integrated red pc-LED was fabricated, and Tulsi plants were grown under this LED during the winter in Meghalaya, a period critical for plant growth due to the low ambient light. Over a 30-day period, the plants exhibited enhanced height and leaf development, demonstrating the practical potential of Mn⁴⁺/Nd³⁺ co-doped Y₂SiO₅ for energy-efficient, wavelength-optimized horticultural lighting.