Abstract: Y1.97-xTi0.03CdxO2S (0≤x≤0.06) phosphors with long afterglow were synthesized by solid-state
reaction. The photoluminescence spectra, decay curves, thermoluminescnece spectra and Chromaticity
coordinate curves were investigated. Results showed that the luminescence and afterglow intensity of
Y1.97-xTi0.03CdxO2S (0≤x≤0.06) reduced gradually with increasing Cd2+ ion content while the shape and
position of emission peak remain unchanged. The Chromaticity coordinate of present phosphor keeps at
(0.5497,0.4415). Furthermore, based on the results of thermoluminescence curves of Ti, Cd single doped
and co-doped Y2O2S phosphors, the doped Cd ion reduces the inherent trap depth of Ti single doped
Y2O2S:Ti, and induces simultaneously a new trap level in Y2O2S:Ti,Cd phosphor. Thus, it was proposed
that the introduced new structure defect by Cd2+ ions should be responsible for the reducing luminescence
and afterglow property.
Abstract: Green-emitting Y3Al5O12: Tb phosphor materials have been widely studied because of their
high luminescence efficiency and stability under the conditions of high irradiance with an electron beam.
In this paper, Green-emitting phosphor of yttrium aluminum garnet (Y3Al5O12 or YAG) doped with Tb3+,
Ce3+ and Gd3+ was synthesized by sol-gel method. By means of TG/DSC, XRD, and photoluminescence
(PL) performance, the sintering condition and its influence on the powder’s emitting performance were
studied. The experimental results showed that, Y2.8Tb0.12 Ce0.08-x GdxAl5O12 synthesized by sol-gel
method was a kind of phosphor of good performance. When the value of x was set at 0.04, the best
emitting performance was obtained. The Y3Al5O12: Tb, Ce, Gd particles had fine size, spherical shape,
filled morphology, high crystallinity, and good brightness.
Abstract: To gain nanometer SrAl2O4:Eu,Dy phosphors, uniform fine precursors of Eu and Dy ion
doping strontium aluminate were prepared by microemulsion technology. Using as-synthesized stuff,
long afterglow phosphors SrAl2O4:Eu,Dy were obtained after sintered at 1200°C. TEM characterization
showed the morphology of their grains is sphere-shaped with size less then 100nm. XRD analysis
illuminated the crystal structure of SrAl2O4:Eu2+, Dy3+ phosphors is monoclinic. Fluorometry
examination detected the peak in emitting spectrum is at 510nm, and at 310nm in exciting spectrum,
which both have little blue shift contrasting to the same kind of phosphors synthesized by solid-state
reaction method. Finally, the major parameters influencing the grain size of prepared phosphor powders
were made a discussion.
Abstract: A new red afterglow phosphor Sr3Al2O6: Eu2+, Dy3+ was synthesized by solid-state reaction and
sintered at 1150°C for 2h in reducing atmosphere. Red long lasting phosphorescence of the prepared
materials is observed in the dark with naked eye after the removal of the excitation light. From the
photoluminescence spectra, the broad emission band centered at 612 nm is confirmed. Excitation band
chiefly lies in visible range and its maximum peak is at 473nm. Luminescence mechanism is studied.
Abstract: Spherical SiO2 particles have been successfully coated with SrSiO3:Eu3+ phosphor layers
through a sol-gel process. The resulted core-shell phosphors were characterized by X-ray diffraction
(XRD), transmission electron microscopy (TEM), photoluminescence spectra as well as kinetic decays.
The XRD results demonstrate that the SrSiO3:Eu3+ layers begin to crystallize on the SiO2 particles after
annealing at 1000oC. The obtained core-shell phosphors have perfect spherical shape. The Eu3+ shows a
strong photoluminescence (PL) (dominated by 5D0-7F2 red emission at 612 nm).
Abstract: A series of phosphors of M2MgSi2O7: Eu2+ (M=Ba,Sr,Ca) have been synthesized and studied.
The excitation spectra measurement showed that the phosphors had absorption in long UV light, the
excitation spectra of the phosphors consisted of two broad bands: one in the range from 280nm to 330 nm
and the other from 360nm to 420 nm. The main excitation band centered at around 395nm was belong to
4f→5d transitions of Eu2+. Analysis of the spectra of Ce3+ and Tb3+ co-doped phosphor showed that
energy transfer from Ce3+ to Tb3+ in Ba2MgSi2O7 under UV excitation was efficient.
Abstract: Sr2B5O9Cl:Eu phosphor with high efficient luminescent material was synthesized by solid-state
reaction method in air. The result of X-ray diffraction showed that the pure Sr2B5O9Cl phase forms at
900°C. The emission spectrum of Sr2B5O9Cl:Eu under 254nm excitation contained two parts. One part
was constituted by a strong peak located at 417nm due to the d→f transition of Eu2+ ion, and the other part
contained five weak peaks between 580-660nm due to the 5D0→7FJ(J=1,2,3) of Eu3+ ion. The infrared
spectrum revealed that both BO3 unites and BO4 unites coexisted in the resultant product. The Eu2+ was
surrounded and protected from being oxidized by the BO4 unites. Both red and blue visible lights were
observed under ultraviolet excitation as a result of the coexistence of Eu2+ ion and Eu3+ ion.
Abstract: Ce3+-doped SrGa2O4 was synthesized by citrate-gel with citric acid as chelate agent and
sintered in a slightly reduced atmosphere of hydrogen and nitrogen mixture. It was found that the
phosphor synthesized by citrate-gel can be sintered at relatively lower temperature. The luminescent
properties of Ce3+-activated SrGa2O4 and the complex Sr(Ga-Al)2O4 were studied.
Abstract: The microstructure and surface micromorphology of ZnSe single crystals grown directly from
zinc and selenium have been investigated using rotation orientation x-ray diffraction (RO-XRD), atomic
force microscope (AFM) and field emission scanning electron microscope (FE-SEM). The ZnSe samples
exhibit only the surface leaning to (111) singular face by the angle of 3.13°, which is the buildup of
two-dimensional dendritic crystal layers. Numerous nuclei and cavities distribute unevenly across the
crystal surface, governing the formation of growth layer, while the dendritic crystal layers develop rapidly
by margining the smaller nuclei. The formation of these microstructure and micromorphology on the
surface of ZnSe crystals depends on the surface supersaturation and the growth parameters.