[Spectral characteristics of Ce3+ in alkali-alkaline earth borate system].

Alkali-alkaline earth borate LiCaBO3 : Ce3+, LiSrBO3 : Ce3+ and LiBaBO3 : Ce3+ were investigated by solid-state method. CaCO3 (99.9%), SrCO3 (99.9%), BaCO3 (99.9%), Li2 CO3 (99.9%), Na2 CO3 (99.9%), K2 CO3 (99.9%), H3BO3 (99.9%) and CeO2 (99.9%) were used as starting materials, After these individual materials were blended and ground thoroughly in an agate mortar, the homogeneous mixture was heated at 700 degrees C for 2 h in a reduced atmosphere (5 : 95 (H2/N2)), and these three phosphors were obtained. The excitation and emission spectra of these phosphors were measured by a SHIMADZU RF-540 fluorescence spectrophotometer. The spectral characteristics of Ce3+ in alkali-alkaline earth borate LiCaBO3, LiSrBO3 and LiBaBO3 were investigated. The emission spectra of Ce3+ in these three phosphors all exhibited a dissymmetrical band, and the emission peaks were located at 428, 436 and 440 nm, respectively. The excitation spectra for 428, 436 and 440 nm emission of these three phosphors showed a dissymmetrical band at 364, 369 and 370 nm, respectively. The effects of Li+, Na+ and K+ on the emission intensities of these three phosphors were studied. The results show that the emission intensities of these phosphors were enhanced, and the maximal emission intensity of doping Li+ is higher than that of Na+ and K+.