Near-unity quantum efficiency and remarkable anti-thermal quenching of Cr3+-activated Gd3AlGa4O12 garnet emitter for advanced broadband NIR light source

Advances in broadband near-infrared (NIR) emitting materials represent a pivotal frontier for next-generation intelligent NIR phosphor-converted light-emitting diode (pc-LED) technologies. However, practical implementation of these materials has been constrained by challenges such as suboptimal quantum efficiency (QE) and pronounced thermal quenching (TQ). In this study, we report the synthesis and comprehensive characterization of broadband NIR-emitting phosphors, Gd 3 AlGa 4 O 12 :Cr 3+ , exhibiting anti-TQ properties without compromising QE. The material's inherent structural rigidity , wide bandgap, and the minimal electron-phonon coupling (EPC) effect provide a foundation for high-performance broadband NIR luminescence. Strategic optimization of Cr 3+ doping concentrations, combined with controlled excited-state electron migration, achieves an internal quantum efficiency (IQE) of 98.23 % and a remarkable anti-TQ capability (135.1 %@483 K). The practical potential is further demonstrated through prototype NIR pc-LED implementation, where integration with a commercial blue LED chip delivers an NIR output power of 285.38 mW at 1170 mA and a wall-plug efficiency (WPE) of 17.42 % at 30 mA, highlighting its potential for use in diverse applications such as plant growth, component analysis, night vision, nondestructive detection, and non-invasive imaging. Overall, this work addresses critical challenges in broadband NIR phosphors and advances the development of high-performance and energy-efficient miniatured broadband NIR light sources .