中国物理B ›› 2010, Vol. 19 ›› Issue (12): 127807-127807.doi: 10.1088/1674-1056/19/12/127807
胡龙, 徐学文, 卢遵铭, 范英, 李养贤, 唐成春
Hu Long(胡龙),Xu Xue-Wen(徐学文),Lu Zun-Ming(卢遵铭),Fan Ying(范英), Li Yang-Xian(李养贤), and Tang Cheng-Chun(唐成春)†
摘要: The luminescence properties of lanthanum silicon oxynitride (La-Si-O-N) series doped by trivalent Ce ions have been investigated to seek for tunable wavelength-conversion phosphor for white light emitting diode applications. Four compound hosts of LaSiO2N, La4Si2O7N2, La5Si3O12N, and La2Si6O3N8 were synthesized and examined in this work. Crystallographic examination for the equal amount of Ce3+ substitution indicated that the covalency degree decreased in a sequence LaSiO2N > La2Si6O3N8 > La4Si2O7N2 > La5Si3O12N, not simply in correlation to the ratio of N3/O2. Excitation and emission spectrum measurements showed the main features of Ce3+ luminescence in the series: the centre of gravity of 5d bands depends on crystal-field splitting more strongly than that on covalency of Ce–N bonding; nephelauxetic effect could not be observed clearly for the investigated series; to some extent Stokes shift was dominated by crystal-field splitting rather than Ce–N covalency degree.
中图分类号: (Impurities in crystals)