Novel Red-Emitting BaBi2B4O10:Eu3+ Phosphors: Synthesis, Crystal Structure and Luminescence.

The novel red-emitting BaBi2-xEuxB4O10 (x = 0.05, 0.1, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6) phosphors were obtained by a crystallization from a glass. Distribution of the Eu3+ ions over cation sites were refined for x = 0.1, 0.3 and 0.4 from single-crystal X-ray diffraction data. Emission and excitation spectra of the Eu3+-doped BaBi2B4O10 phosphors were investigated for the first time, where it was shown that characteristic lines are attributed to the intraconfigurational 4f-4f transitions. The optimal concentration for the BaBi2-xEuxB4O10 phosphors is x = 0.4, after which a luminescence intensity decreases. The CIE chromaticity coordinates for the BaBi2B4O10:Eu3+ (x = 0.4) phosphor (0.65, 0.35) are close to the NTSC standard values (0.67, 0.33) for commercial red phosphor. The obtained results show that the BaBi2B4O10:Eu3+ phosphors are promising candidates for solid state lighting application.