Preparation and photoluminescence characterization of LuBO3:Bi3+, Cr3+ fluorescent materials for non-visual lighting applications

Firstly, ellipsoidal LuBO3: Bi3+/Cr3+ fluorescent materials with a particle size of approximately 2 μm were successfully synthesized using the high-temperature solid-phase method. Under excitation at 327 nm, LuBO3: Bi3+ emits blue light due to the 3P1 → 1S0 transitions of Bi3+, while LuBO3: Cr3+ emits broadband near-infrared light upon excitation at 475 nm, attributed to the 4T2 → 4A2 transitions of Cr3+. Secondly, following the determination of the optimal doping concentrations, co-doped LuBO3 fluorescent materials with Bi3+ and Cr3+ were prepared. This co-doping facilitated energy transfer from Bi3+ to Cr3+, resulting in the emission of near-infrared light from Cr3+ when exposed to ultraviolet excitation. The underlying energy transfer mechanism in this process is dipole–dipole interaction. The quantum efficiency of the LuBO3: 0.02Bi3+, 0.01Cr3+ fluorescent material was measured to be 67.8 %. Concurrently, the material's thermal stability was assessed and analyzed. At 423 K, the light intensity reached 80.4 % of the initial intensity, and a water stability test revealed that after 5 h, the light intensity remained at 76.2 % of the initial intensity. These findings underscore the potential for the fluorescent material in non-visual lighting applications.