LEI Fang, XU Chong-fu, YANG Min-li, FANG Jun-zhuo, CHEN Hao-ping. Preparation of Blue Phosphor SrAl<sub>2</sub>Si<sub>2</sub>O<sub>8</sub>:Eu<sup>2+</sup> with Sol-gel Method[J]. Chinese Journal of Luminescence, 2006,27(4): 479-483
LEI Fang, XU Chong-fu, YANG Min-li, FANG Jun-zhuo, CHEN Hao-ping. Preparation of Blue Phosphor SrAl<sub>2</sub>Si<sub>2</sub>O<sub>8</sub>:Eu<sup>2+</sup> with Sol-gel Method[J]. Chinese Journal of Luminescence, 2006,27(4): 479-483DOI:
Preparation of Blue Phosphor SrAl2Si2O8:Eu2+ with Sol-gel Method
Much attention has been paid to search for high-efficient phosphor with the development of displaying device.Some commercial blue phosphors
such as BaMgAl
10
O
17
:Eu
2+
do not meet the ever demanding requirements
they suffer decreasing performance of brightness and color quality because of the serious deterioration.New blue phosphor with stable hosts was belived to be a better way to solve this problem.In the(silicate) host series
Eu
2+
appeared to be a feasible candidate for the blue emitting vehicle originating from(5d-4f)(around 420 nm) transition.SrAl
2
Si
2
O
8
:Eu
2+
a potential excellent blue phosphors suitable for making PDP device and other luminescent apparatus
are conventionally prepared using solid-state reaction at high temperature.However
it is(difficult) to control over particles size and crystal structure at this condition
meanwhile the reaction temperature is so high
serious challenging problems arise to the equipment.Sol-gel method is one of the "soft" chemical methods
which have been employed successfully to prepare phosphor particles with better morphology and(operate) in a lower temperature
compared with solid-state reaction
in recent years.We reported the synthesis of the blue rare earth phosphor SrAl
2
Si
2
O
8
:Eu
2+
by sol-gel method.The sol-gel method was adopted by reacting corresponding nitrate and tetraethylothosilicate(TEOS) at a 85℃ water bath to form a gel
from which the dried precursor was reduced at relatively low temperature of 921℃ to(generate) a blue fluorescence material SrAl
2
Si
2
O
8
:Eu
2+
.The product synthesized was characterized by thermogravimetry(TG)
differential scanning calorimetry(DSC)
X-ray diffraction analysis(XRD)
and fluorescence spectrophotometry.Influential factors in the process of the sol-gel preparation
such as pH value
(ethanol) content
(amount) of citric acid
were studied in depth
and the optimal conditions for synthesizing SrAl
2
Si
2
O
8
:Eu
2+
were determined.XRD analysis indicates that when the mole ratio between citric acid and metal ion was 1:1
the minimal amount of anhydrous ethanol sufficient to secure a total dissolution of tetraethylothosilicate was used
and the pH value between 1.0~2.0 was maintained
the pure SrAl
2
Si
2
O
8
with hexagonal crystal phase could be obtained.The light emitting analysis showed that with the monitoring wavelength 463 nm emission the product gave an exited peak at 327 nm
and an incident light with wavelength 394 nm could generate a fluorescent light with emitting wavelength 468 nm from this phosphor.