LI Qi-hua, LIU Li-min, ZENG Li-hua, LEI Chun-hua, CAO Xiao-mei, PENG Yi-an, LIAN Shi-xun. Synthesis and Luminescent Properties of Ca<sub>3</sub>La(BO<sub>3</sub>)<sub>3</sub>:Tb<sup>3+</sup>Phosphor[J]. Chinese Journal of Luminescence, 2006,27(2): 183-186
LI Qi-hua, LIU Li-min, ZENG Li-hua, LEI Chun-hua, CAO Xiao-mei, PENG Yi-an, LIAN Shi-xun. Synthesis and Luminescent Properties of Ca<sub>3</sub>La(BO<sub>3</sub>)<sub>3</sub>:Tb<sup>3+</sup>Phosphor[J]. Chinese Journal of Luminescence, 2006,27(2): 183-186DOI:
the borate luminescence materials have been paid much attention owing to their properties of low preparation temperature and high luminescent efficiency.In order to search for the new green-photoluminescence material
Ca
3
La(BO
3
)
3
:Tb
3+
was synthesized by high temperature solid state reaction at a weak reductive atmosphere which was made by the active carbon powder.The samples had been characterized by scanning electron microscopy(SEM)
laser-diffraction size analyzer and fluorospectrophotometer.The results showed that most of the crystals were cylindric and the(average) size of the crystals was about 41 m.Excitation and emission spectrum of the Ca
3
La(BO
3
)
3
:Tb
3+
and Ca
3
La(BO
3
)
3
:Tb
3+
Ce
3+
phosphors were measured by the fluorospectrophotometer at room temperature.In analysis of the emission spectrum for Ca
3
La(BO
3
)
3
:Tb
3+
under 254 nm excitation at room temperature
there are four main emission peaks at 496
549
594
628 nm
among which the intensity of the 549 nm line is the highest.They belonged to the characteristic emission of Tb
3+
ions.Besides
the luminescent intensity of the Ca
3
La(BO
3
)
3
:Tb
3+
powder changed along with different concentrations of Tb
3+
ions
and the optimum concentration of Tb
3+
in Ca
3
La(BO
3
)
3
is x(Tb)=0.25.According to the dependence of the concentration of Tb
3+
in Ca
3
La(BO
3
)
3
under the excitation of 251 nm
it was confirmed that the mechanism of concentration selfquenching of Tb
3+
5
D
4
7
F
5
transition is electric dipole-dipole interaction.The influence of Ce
3+
on the emission intensity of Tb
3+
was also investigated
after adding low concentration of Ce
3+
to the system of Ca
3
La-(BO
3
)
3
:Tb
3+
the luminescence intensity increased only slightly
so Ce
3+
may not be a good sensitizer to Tb
3+
in Ca
3
La(BO
3
)
3
.In addition
it has been confirmed that when a flux
Li
2
CO
3
was added
the 549nm emission corresponding to
5
D
4
7
F
5
transition was intensified greatly.Ca
3
La(BO
3
)
3
:Tb
3+
phosphor could absorb ultraviolet radiation and emit green light.Compared with the former results of other borate luminescent materials
when Ca
3
La(BO
3
)
3
:Tb
3+
phosphor was excited by 254 nm UV light
stable and much stronger green light could be emitted
so it is promising to apply in the production of green fluorescent lamp.