Achieving High-Performance Near-Infrared Cr3+-Activated Phosphor via A&C Lattice Sites Cosubstitution Strategy in Garnet for Plant Lighting

• • Cosubstitution of Ca2+ and Sn4+ in Y3Ga5O12:Cr3+ garnet shifts emission peak from 708 to 768 nm, enabling spectral tunability for plant lighting (Pfr absorption). • • Optimized phosphor Y2.6Ca0.4Ga4.6Sn0.4O12:0.07Cr3+ achieves EQE of 34.96%, a 2.71-fold intensity enhancement over the unsubstituted host, attributed to octahedral Jahn-Teller distortion. • • Thermal stability reaches 91.3% at 423 K, owing to weak electron-phonon coupling and oxygen vacancy defects, ensuring reliable operation in high-temperature LED environments. • • NIR pc-LED device demonstrates electroluminescence efficiency of 18.8% at 100 mA and <5% intensity loss after 30 days, validating long-term operational stability for agricultural lighting.