Remarkable broadband NIR emission of BaCa2MgSi2O8:Cr3+ phosphors and Eu2+ co-doping modulation

Developing high-performance broadband NIR (near-infrared) phosphors remains a crucial pursuit for the next-generation smart NIR light source. This study demonstrates the successful synthesis of BaCaMgSiO:Cr phosphors exhibiting exceptional broadband NIR emission a high-temperature solid-state reaction. Notably, the 0.03Cr doped composition, under 485 nm excitation, shines with a remarkable broadband emission spanning 700 nm–1100 nm and boasts a full width at half maximum (FWHM) of 134 nm. This work meticulously explores the intricate interplay between Cr doping concentration, temperature, crystal field strength, and the Huang-Rhys parameter, shedding light on the underlying luminescence mechanisms. Moreover, the BaCaMgSiO:0.03Cr phosphor exhibits exceptional thermal stability, retaining approximately 70 % of its integrated emission intensity at 425 K compared to room temperature. To further expand the excitation range, Eu was introduced as a co-dopant, successfully broadening the excitation spectrum to encompass nearly the entire ultraviolet–visible region (ranging from 250 nm to 750 nm). The presence of Eu→Cr energy transfer was elucidated, and the impact of Eu doping was thoroughly investigated. Moreover, the synthesized phosphor has been successfully integrated into a NIR phosphor-converted light-emitting diode (pc-LED), showcasing their potential application in the realms of night vision and NIR vascular imaging. These findings offer invaluable insights into Cr luminescence behavior and pave the way for the development of novel NIR phosphors with enhanced functionalities, propelling us closer to the realization of next-generation smart lighting solutions.