A novel high color purity blue-emitting phosphor: CaBi2B2O7:Tm3

•A series of Tm3+-doped CaBi2B2O7 blue-emitting phosphors were prepared.•The optimum doping content of Tm3+ ions was found.•The critical distance and concentration quenching mechanism was discussed.•The color purity of as prepared sample was analyzed and compared. A series of Tm3+-doped CaBi2−xB2O7:xTm3+ (0.02≤x≤0.12) blue-emitting phosphors with high color purity were prepared by solid-state reaction method. The crystal structure and luminescence properties of the as-prepared phosphors were studied. This phosphor shows a satisfactory blue performance (peak at 453nm) due to the 1D2→3F4 transition of Tm3+ excited by 357nm light. Investigation of Tm3+ content dependent emission spectra indicates that x=0.04 is the optimum doping content of Tm3+ ions in the CaBi2B2O7 host. The critical distance and the concentration quenching mechanism were also investigated. In particular, the color purity of as prepared sample was analyzed and the result shows that the color purity of CaBi2B2O7:Tm3+ is higher than the commercial blue phosphor BaMgAl10O17:Eu2+ (BAM:Eu2+) and the latest reported Tm3+ doped blue phosphors. The present work suggests that the CaBi2B2O7:Tm3+ phosphor is a potential blue-emitting candidate for the application in the near-UV WLEDs.