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.