A novel high color purity blue-emitting phosphor: CaBi_2B_2O_7:Tm~(3+)

摘要

A series of Tm~(3+)-doped CaBi_(2－x)B_2O_7:xTm~(3+) (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 453 nm) due to the ~1D_2 → ~3F_4 transition of Tm~(3+) excited by 357 nm light. Investigation of Tm~(3+) content dependent emission spectra indicates that x=0.04 is the optimum doping content of Tm~(3+) ions in the CaBi_2B_2O_7 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 CaBi_2B_2O_7:Tm~(3+) is higher than the commercial blue phosphor BaMgAl_(10)O_(17):Eu~(2+) (BAM:Eu~(2+)) and the latest reported Tm~(3+) doped blue phosphors. The present work suggests that the CaBi_2B_2O_7:Tm~(3+) phosphor is a potential blue-emitting candidate for the application in the near-UV WLEDs.