“In response to the urgent demand for compact light sources in portable near-infrared spectrometers, phosphor conversion light-emitting diodes (pc LEDs) have shown great potential. Among them, Cr3+activated near-infrared phosphors are considered highly competitive material systems due to their high efficiency and wavelength tunable properties. However, the reported near-infrared phosphors activated by Cr3+have issues with narrow FWHM (FWHM<150 nm) and short emission wavelength (λ em<750 nm). This study designed and synthesized a novel garnet structured near-infrared fluorescent powder Na2Lu2Ga4GeO12: Cr3+(NLGG: Cr3+) using the [Na+- Ge4+] co substitution strategy. Under 468 nm blue light excitation, the optimized NLGG: 0.08Cr3+sample exhibits broadband emission with a peak at 780 nm covering 600-1100 nm. Its FWHM reaches 196 nm, and the internal and external quantum efficiencies (IQE, EQE) are 56% and 22%, respectively. Spectral analysis and crystal field calculations confirm that its broadband emission originates from Cr3+occupying a single Ga3+site with moderate crystal field intensity. By adjusting the Cr3+concentration, continuous tuning of the emission peak from 742 nm to 790 nm and FWHM from 182 nm to 196 nm can be achieved. NIR pc LED devices were prepared using the fluorescent powder and blue LED chips, and their potential applications in biomedical imaging, night vision, and non-destructive testing were demonstrated. #Rewriting #, researchers have explored a Cr3+activated near-infrared fluorescent powder system in response to the demand for compact light sources in portable near-infrared spectrometers. Through innovative strategies, new fluorescent powders have been synthesized to solve the limitations of existing materials and provide new solutions for related field applications.”