Effect of R+ (R = Li, Na and K) codoping on the luminescence enhancement of broadband NIR BaZrGe3O9:Cr3+ phosphors for NIR LED

Broadband near-infrared (NIR) phosphors have aroused wide attention due to its extensive application in diverse fields. Therefore, it is vitally important to discover highly efficient and stable broadband NIR phosphor. In this study, we report a novel broadband Cr3+-activated BaZrGe3O9 phosphor. A series of properties including phase purity, crystal structure, spectroscopic properties, fluorescence decay lifetime, and thermal quenching behavior are investigated in detail. The obtained phosphor shows a broad absorption in the near ultraviolet and visible region and a broadband emission with full width at half maximum of ~160 nm. In addition, there exists charge imbalance due to the unequal substitution of Zr4+ and Cr3+ ions. The effect of charge compensation (codoping of Li+, Na+, and K+ ions) on the luminescent properties of Cr3+-activated samples was also investigated. Hence, the obtain NIR phosphors have a potential application for the NIR pc-LED.