Abstract:LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors were synthesized by solid state reaction. The starting materials CaCO3, SrCO3, BaCO3, H3BO3, Li2CO3, Na2CO3, K2CO3 and Tb4O7 (99.99% in mass) in appropriate stoichiometric ratio were mixed in the alumina crucible, then the mixed powders were calcined at 700 ℃ for 2 h, and LiCaBO3∶Tb3+, LiSrBO3∶Tb3+ and LiBaBO3∶Tb3+ phosphors were obtained. The emission and excitation spectra were measured by a Shimadzu RF-540 ultraviolet spectrophotometer. All the photoluminescence properties of these phosphors were measured at room temperature. The emission spectra of LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors show several bands, and the main emission peaks correspond to the 5D4→7F6(486, 486, 488 nm), 5D4→7F5(544, 544, 544 nm), 5D4→7F4(590, 595, 593 nm) and 5D4→7F3(620, 620, 616 nm) typical transitions of Tb3+, and the typical transitions of Tb3+ happens to split because of the effects of LiM(M=Ca, Sr, Ba)BO3 crystals field. The excitation spectra for the 544 nm green emission of LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors illuminate that these kinds of phosphors can be effectively excited by ultraviolet (350-410 nm) light, and emit green light, therefore, they are promising phosphors for white light emitting diodes. Effects of activation and charge compensation on the luminescence intensities of LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors were studied, and the results show that the intensities were obviously effected.
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