The bulk crystal growth and yellow–orange spectral performances of Pr³⁺: BaF₂ and Pr³⁺/RE³⁺(RE³⁺ = Gd³⁺, Y³⁺, Lu³⁺, Ce³⁺): BaF₂ crystals

In this study, we synthesized Pr³⁺:BaF₂ and Pr³⁺/RE³⁺ (RE = Gd, Y, Lu, Ce) co-doped BaF₂ crystals, exploring their novel spectral properties through co-doping with Gd, Y, Lu, and Ce ions. The research demonstrates that both singly doped and co-doped BaF₂ crystals have broader full width at half maximum (FWHM) values (24.82 nm) and longer fluorescence lifetimes (244 µs) than typical Pr³⁺-doped crystals, indicating their potential as gain media for Pr³⁺-based yellow–orange lasers. Notably, co-doping with Gd³⁺ enhances yellow–orange light emission up to 12 times, Y³⁺ up to 8 times, and Lu³⁺ up to 9 times. The effect is more pronounced with increased concentrations of co-dopants, while Ce³⁺ doping mainly expands the FWHM. Low-temperature spectral analysis confirms that co-doping alters the spectral performance by disrupting symmetric clusters in Pr: BaF₂ crystals, forming new clusters with lower symmetry, and enhancing lattice distortion, thus increasing the absorption cross-section to 1.69 × 10⁻²⁰ cm². Our findings highlight the significant potential of these crystals in biomedical, spectroscopic, information processing, atmospheric detection, and remote sensing applications.