ZHAO Jian-jun, LI Cheng-yu, WANG Shu-bin, SU Qiang. Long Lasting Phosphorescence of Tb<sup>3+</sup>-doped Alkaline Earth Borosilicate Glasses[J]. Chinese Journal of Luminescence, 2004,25(6): 655-660
ZHAO Jian-jun, LI Cheng-yu, WANG Shu-bin, SU Qiang. Long Lasting Phosphorescence of Tb<sup>3+</sup>-doped Alkaline Earth Borosilicate Glasses[J]. Chinese Journal of Luminescence, 2004,25(6): 655-660DOI:
The glasses have some advantages over polycrystalline forms because it is easier to be fabricated into products with various shapes such as bulk plates and fibers. The glasses with long lasting phosphorescence phenomenon are worth investigating thoroughly not only for its conventional use as indicator or craftwork in darkness
but also on account of searching new optoelectronic materials or optical storage devices. In this article
a new long afterglow luminescent glass material was synthesized and reported. The long lasting phosphorescent glass with the composition (in mol%) of 40BaO-10B
2
O
3
-50SiO
2
:0.2Tb
2
O
3
(BBST) was synthesized by the high temperature solid-state reaction at atmosphere ambient. The glass sample was characterized by the IR
UV-Vis absorption
fluorescence and thermoluminescence spectra
respectively. Bright green long lasting phosphorescence was observed in Tb
3+
-doped barium borosilicate glasses after the irradiation with a UV lamp (
max
=254 nm) for 30 min at room temperature. This green phosphorescence can be observed with naked eyes in the dark for up to 8 h after removing the UV lamp. The afterglow phosphorescence spectrum with dominant peak at 543 nm is almost identical with the emission spectrum of BBST glass sample in peak-position and shape. This indicates that the green phosphorescence originates from the characteristic emission of Tb
3+
. The peak at 543 nm of the phosphorescence spectrum is associated with
5
D
4
7
F
5
transition of Tb
3+
. The decay curve of the afterglow does not obey a simple exponential rule. The phosphorescence decays quickly at former 200 s and then decreases slowly in latter stage. The themoluminescence curve of BBST glass sample consists of five Gaussian-fitted components
which suggests that many kinds of traps exist in the glass matrix. The possible mechanism of the long lasting phosphorescence is suggested to be due to the recombination of electrons and holes at shallow traps in the glass matrix that can be thermally released at room temperature
and energy transfer between the recombination centers and Tb