Enhanced blue emission of Ba₃Ga₂O₆: Bi³⁺ phosphor co-doped with alkali metal ions

A novel Bi³⁺ doped Ba₃Ga₂O₆ phosphor was successfully synthesized by high-temperature solid-state method in this work. The results of X-ray diffraction (XRD) characterization, scanning electron microscope (SEM) characterization and energy dispersive spectrometer (EDS) characterization indicate that Bi³⁺ ions were doped successfully into the lattice_. The phosphor has a broad emission band covering the 350-580 nm spectral region peaked at 416 nm under the excitation at 340 nm, due to the ³P₁ → ¹S₀ transition of Bi³⁺ ions. Furthermore, when Na⁺ ions and K⁺ ions were co-doped, the emission intensity increased by 1.53 times and 1.55 times, respectively. By combining Ba₃Ga₂O₆: Bi³⁺, K⁺, the commercial green phosphor (Ba, Sr)₂SiO₄: Eu²⁺ and the commercial red phosphor CaAlSiN₃: Eu²⁺ with a 340 nm UV chip, a pc-white LED was fabricated successfully. And the chromaticity coordinates of the WLED is (0.3647, 0.3329), the value of Correlated Color Temperature (CCT) is 4136 K and the Color Rendering Index (CRI) = 88.4. All results indicate that Ba₃Ga₂O₆: Bi³⁺ phosphor can make a great contribution to the field of NUV-based WLEDs.