bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Blue-Green-Emitting Phosphor Gd4.67Si3O13:Tb3+
Authors: Jin Ye , Wang Qingping
Published: April 2016

A novel blue-green-emitting phosphor Gd4.67Si3O13:Tb3+ has been synthesized by a conventional high temperature solid-state method at 1350 °C for 6 h. X-ray diffraction and photoluminescence spectra were used to characterize the as-synthesized
phosphor. The excitation spectrum is composed of a broadband and two sharp peaks, at 274 nm, and 311 nm, respectively. The emission spectrum is composed of multiple sharp peaks, of which the strongest peak is at 544 nm (5D4 →7F5). The critical
doping content of Tb3+ is 5%, with the emission intensity increasing proportionally with Tb3+ concentration increase until it reaches 5%. As doping concentration from 5% to 7%, the luminescence intensity gradually reduces. Concentration quenching mechanism for Tb3+
is demonstrated to be dipole–dipole interaction. The Commission Internationale de L’Eclairage (CIE) coordinates are also investigated in this work. The CIE coordinates of the Gd4.67Si3O13:0.03Tb3+ phosphor upon 311 nm excitation are (0.242,
0.323). All the results indicate that the blue-green-emitting phosphor Gd4.67Si3O13:Tb3+ has potential research value.
Improved Near-Infrared Up-Conversion Emission of Tm3+ Sensitized by Yb3+ and Ho3+ in LuF3 Nanocrystals
Authors: Xu Xuhui , Wu Yumei , Bian Wenjuan , Yu Xue , Zhang Buhao , Li Qianyue , Qiu Jianbei , Liu BiTao
Published: April 2016

In the present work, mono-disperse and uniform orthorhombic lutetium fluoride (LuF3) nanocrystals with an average size of about 35 nm have been successfully synthesized by a simple ionothermal method without any template. The infrared (IR) to visible up-conversion (UC) photoluminescence
of LuF3 doped with Yb3+, Tm3+, and Ho3+ under 980 nm excitation was systemically studied. The intensity of near infrared (NIR) to visible up-conversion emission of Tm3+ was improved efficiently by adding Yb3+ and Ho3+ in LuF3,
especially for the broad NIR emission band located at 812 nm. Meanwhile, compared to the Yb3+ and Tm3+ co-doped LuF3, the ratio of red to green emission in the Yb3+, Tm3+, and Ho3+ co-doped LuF3 changed greatly, and
a bright yellowish-green emission was observed under 980 nm laser excitation. It shows that Yb3+, Tm3+ and Ho3+ co-doped LuF3 nanocrystals provided a potential application in vitro and in vivo bio-imaging, color displays and optical
storage.
Upconversion Luminescence Properties of NaYF4 Nanocrystals Precipitated Nd3+/Yb3+/Ho3+ Tri-Doped Oxyfluoride Glass Ceramics
Authors: Gao Yuan , Hu Yuebo , Zhou Dacheng , Qiu Jianbei
Published: April 2016

Transparent oxyflouride glass ceramics composed of SiO2–Al2O3–Na2O–NaF–YF3 tri-coped with Nd3+/Yb3+/Ho3+ were prepared by thermal treatment. Segregation of NaYF4
nanocrystals in the matrix was confirmed from structural analysis by means of X-ray diffraction and transmission electron microscopy. Compared with glass samples, very strong green upconversion (UC) luminescence due to the Ho3+:(4F5, 5S2)→5I8
transition was observed in the glass ceramics under 808 nm excitation. It was found that upconversion intensity of Ho3+ strongly depends on the Nd3+ concentration, and the energy transfer process from Nd3+ to Ho3+ via Yb3+ was proposed.
Synthesis and Luminescent Properties of CaSnO3:Eu Nanopowder Prepared by a Sol–Gel Route
Authors: Fu Xiaoyan , Zhao Tuyuan , Zhang Yan , Chen Yibin , Zhang Hongwu
Published: April 2016

Luminescent properties of nanocrystalline CaSnO3:1%Eu have been investigated in order to develop novel red phosphors. The results indicate that high-quality nanoparticles with controlled stoichiometry and microstructure were prepared by a sol–gel method using citric
acid and EDTA as complexes. There are two broad excitation bands located at 240 and 270 nm existing in the excitation spectrum in addition to the characteristic excitation peaks of Eu3+. Further investigations show that the excitation band located at 240 nm can be assigned to the
host absorption while the Eu–O charge transfer is responsible for the 270 nm excitation band. These results indicate that the host can efficiently transfer energy to the Eu3+ ions. The more important is that since the symmetry of Eu3+ ions is lower, the pure red
emission (5D0 → 7F2 transition located at 618 nm) is predominant over all the emission. This mean CaSnO3:Eu is a potential candidate for red luminescent materials.
Structure and Optical Thermometry Characterization of Er3+/Yb3+ Co-Doped BaGd2CuO5
Authors: Li Xiaodong , Song Yanjie , Yang Yanmin , Mi Chao , Liu Yanzhou , Yu Fang , Liu Linlin , Zhang Jiao , Li Zhiqiang
Published: April 2016

Er3+/Yb3+ co-doped BaGd2CuO5 upconversion luminescent materials are obtained by solid phase method. Rietveld refinement on X-ray diffraction data indicates that Er3+/Yb3+ ions are inclined to occupy the Gd(1) site in
the structure of BaGd2CuO5 (green phase). Two green emission peaks located at 523 nm and 547 nm have been produced by the excitation of 971 nm LD. The fluorescence intensity ratio (FIR) of the two green emission peaks have been investigated in the temperature range of
290 K–594 K. The maximum sensitivity derived from the FIR technique of the green upconversion emission is approximately 0.0038 K−1, and it has a high transmission power at low excitation density. This result implies that the Er3+/Yb3+ co-doped BaGd2CuO5
phosphors can play an important role in temperature measurements with a better sensitivity.
Effect of Ce3+ Concentration on the Luminescence Properties of Ce3+/Er3+/Yb3+ Tri-Doped NaYF4 Nanocrystals
Authors: Liu Xuee , Qiu Jianbei , Xu Xuhui , Zhou Dacheng
Published: April 2016

In order to investigate the effect of Ce3+ concentration on the emission properties of Er3+/Yb3+ codoped NaYF4 nanocrystals, Ce3+/Er3+/Yb3+ tri-doped NaYF4 nanocrystals were prepared through a facile
EDTA-assisted hydrothermal method. The upconversion (UC) and the near infrared (NIR) emission properties of Er3+ ions were systematically investigated in the NaYF4:Ce3+/Er3+/Yb3+ nanocrystals. Under 980 nm excitation, with the increasing
of Ce3+ concentration, the emission intensity of Er3+ at 1550 nm (4I13/2 → 4I15/2) band increases initially and then decreases. The increase of the fluorescence intensity of 1550 nm is due to the energy transfer between
Er3+ and Ce3+ ions: Er3+:4I11/2 +Ce3+:2F5/2 → Er3+:4I13/2 +Ce3+:2F7/2. But when Ce3+ doping concentration is 2.0%, the cross
relaxation:Er3+:4I13/2 +Ce3+:2F5/2 →Er3+:4I15/2 +Ce3+:2F7/2 happens, which depopulates the 4I13/2 level of Er3+ and results
in the decrease of the emission intensity of Er3+ at 1550 nm band. Meanwhile, incorporation of Ce3+ dramatically decreases the visible UC emission intensity. A possible emission mechanism was proposed.
Ag@SiO2/LaF3:Eu3+ Composite Nanostructure and Its Surface Enhanced Luminescence Effect
Authors: Han Qingyan , Zhang Yaqiong , Ren Zebin , Wang Zhaojin , Gao Wei , He Enjie , Zheng Hairong
Published: April 2016

Ag@SiO2/LaF3:Eu3+ core–shell nanostructure was synthesized with a wet chemical method in which the SiO2 layer functioned as a separation layer between Ag-core and LaF3:Eu3+ luminescence material. With this system,
surface enhanced luminescene of LaF3:Eu3+ with Ag substrate was investigated, and an obvious enhancement effect was observed. The dependence of the luminescence enhancement on the distance between the luminescence shell and the metallic core was studied too. It is believed
that the enhancement effect presented by the current hybrid nanostructure system has great potential in the development of photovoltaic cells.
Luminescence Properties of Sm3+/Eu3+ Co-Doped ZnO Quantum Dots
Authors: Liu Fengyi , Li Hong , Hu Yajing , Jin Na , Mou Yun , Yang Kun , Ye Zuhu , Li Mingyue , Xie Ya-Hong
Published: April 2016

In order to improve luminescence properties of semiconductor ZnO quantum dots (QDs), Sm3+/Eu3+ co-doped ZnO QDs have been controllably synthesized by sol–gel method in this paper. ZnO QDs have a spherical shape with mean diameter at about 5–6 nm, which
was characterized by high-resolution transmission electron microscopy (HRTEM). ZnO QDs have hexagonal wurtzite structure with parts of Sm3+ and Eu3+ incorporated into the lattice, which was demonstrated by X-ray Diffraction (XRD). Luminescence properties at room temperature
(RT) of different amount of Sm3+ and 2 mol% Eu3+ doped ZnO QDs were examined in-depth by optical spectra. In contrast to the Pr3+/Eu3+ co-doped fluorescent performance researched in our previous study, the photoluminescence (PL) spectra indicates
the unique luminescence properties of Sm3+/Eu3+ co-doped ZnO QDs. In addition, fluorescence lifetimes were obtained to illustrate the luminous mechanism.
A New Kind of Blue Hybrid Electroluminescent Device
Authors: Wang Junling , Li Zhuan , Liu Chunmei
Published: April 2016

Bright blue Electroluminescence come from a ITO/BBOT doped silica (6×10−3 M) made by a sol–gel method/Al driven by AC with 500 Hz at different voltages and Gaussian analysis under 55 V showed that blue emission coincidenced with typical triple emission from
BBOT. This kind of device take advantage of organics (BBOT) and inorganics (silica). Electroluminescence from a singlelayered sandwiched device consisting of blue fluorescent dye 2,5-bis (5-tert-butyl-2-benzoxazolyl) thiophene (BBOT) doped silica made by sol–gel method was investigated.
A number of concentrations of hybrid devices were prepared and the maxium concentration was 6×10−3 M. Blue electroluminescent (EL) always occurred above a threshold field 8.57×105 V/cm (30 V) at alternating voltage at 500 HZ. The luminance of the devices
increased with the concentration of doped BBOT, but electroluminescence characteristics were different from a single molecule’s photoluminescence properties of triple peaks. When analyzing in detail direct-current electroluminescence devices of pure BBOT, a single peak centered at 2.82
eV appeared with the driven voltage increase, which is similar to the hybrid devices. Comparing Gaussian decomposition date between two kinds of devices, the triple peak characteristic of BBOT was consistent. It is inferred that BBOT contributed EL of the hybrid devices mainly and silica may
account for a very small part. Meanwhile the thermal stability of matrix silica was measured by Thermal Gravity-Mass Spectroscopy (TG-MS). There is 12 percent weight loss from room temperature to 1000 °C and silica has about 95% transmittance. So the matric silica played an important role
in thermal stability and optical stability for BBOT. In addition, this kind of blue electroluminescence device can take advantages of organic materials BBOT and inorganic materials silica. This is a promising way to enrich EL devices, especially enriching inorganic EL color at a low cost.
Synthesis and Near-Infrared Luminescent Properties of NaGdF4:Nd3+@NaGdF4 Core/Shell Nanocrystals with Different Shell Thickness
Authors: Li Xinke , You Fangtian , Peng Hongshang , Huang Shihua
Published: April 2016

The near-infrared to near-infrared (NIR-to-NIR) photoluminescence of nanocrystals has outstanding advantages in biological imaging. NaGdF4:Nd3+ core nanocrystals and NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals with different shell
thicknesses were synthesized by a simple solvothermal method. The obtained nanocrystals were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The phase of all nanocrystals is hexagonal. NaGdF4:Nd3+ core nanocrystals have an
average size of 6 nm. By controlling core–shell ratio for 1:2 and 1:3, we obtained NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals with average sizes of 10 nm and 11 nm, respectively. When excited at 808 nm, strong NIR emission was observed. The emission peaks
at ∼860 nm, ∼1060 nm and ∼1330 nm correspond to the transitions from the 4F3/2 statetothe 4I9/2, 4I11/2 and 4I13/2 state of Nd3+ ions, respectively. The emission intensity of NaGdF4:Nd3+@NaGdF4
core/shell nanocrystals is stronger than that of the core. The intensity increases with the increase of shell thickness. The shell improves the luminous efficiency by reducing surface defects. The decay time of Nd3+ emission in NaGdF4:Nd3+@NaGdF4
core/shell nanocrystal is longer than that in NaGdF4:Nd3+ core, indicating that the shell isolates effectively the emitting ions (Nd3+)from the quenching defects. With the increase of shell thickness, the decay time becomes longer. Within a certain range of
shell thickness, thicker shell can protect the emitting Nd3+ ions on the surface of core nanocrystals more effectively.
Intracellular Temperature Imaging in Gold Nanorod-Assisted Photothermal Therapy with Luminescent Eu(III) Chelate Nanoparticles
Authors: Ding He , Yang Lin , Peng Hongshang , Wang Xiaohui , You Fangtian , Hou Lingling
Published: April 2016

Eu-tris(dinaphthoylmethane)-bis-(trioctylphosphine oxide) (Eu-DT) molecules encapsulated by Polystyrene and bis(trimethoxysilyl)decane nanoparticles were prepared via a modified encapsulation-reprecipitation method and show a high sensitivity to sense temperature. After surface modification
with poly-L-lysine, the fluorescent nanoparticles obtained a well biocompatibility and low toxicity at a certain concentration. In the physiological temperature range (25–45 °C), the fluorescence of the nanoparticles is rather sensitive to temperature with a sensitivity of
−2.6%/°C. The temperature nanosensors and gold nanorods were internalized into living HepG2 cells. The fluorescence intensity of phagocytic nanoparticles decreased with the irradiation of 808-nm laser, which were captured by Epi-fluorescence microscope.
Growth and Properties of Cl− Incorporated ZnO Nanofilms Grown by Ultrasonic Spray-Assisted Chemical Vapor Deposition
Authors: Chen Tingfang , Wang Aiji , Kong Lingrui , Li Yongliang , Wang Yinshu
Published: April 2016

Pure and Cl− incorporated ZnO nanofilms were grown by the ultrasonic spray-assisted chemical vapor deposition (CVD) method. The properties of the nanofilms were investigated. The effects of growth temperature and Cl− concentration on the crystal structure,
morphology, and optical properties of the nanofilms were studied. Temperature plays an important role in the growth mode and morphology of the pure nanofilms. Preferential growth along the c-axis occurs only at modulating temperature. Lower temperature suppresses the preferential growth,
and higher temperature suppresses the growth of the nanofilms. The morphologies of the nanofilms change from lamellar and spherical structures into hexagonal platelets, then into separated nanoparticles with an increase in the temperature. Incorporating Cl− results in the
lattice contracting gradually along with c-axis. Grains composing the nanofilms refine, and the optical gap broadens with increasing of Cl− concentration in growth precursor. Incorporating Cl− could reduce oxygen vacancies and passivate the non-irradiated
centers, thus enhancing the UV emission and suppressing the visible emission of ZnO nanofilms.
An Electrostatically Self-Assembled Thin Film Made of Zn-Substituted Tungstoborate and Rhodamine B with Photoelectrochemical Properties
Authors: Mao Xu , Zhang Jia-Ning , Gao Li-Hua , Su Yu , Chen Peng-Xia , Wang Ke-Zhi
Published: April 2016

An electrostatically self-assembled multilayer thin film consisting of alternating layers of Keggin polyoxometalate of Zn-substituted tungstoborate (BW11Zn) and Rhodamine B (RhB) has successfully been prepared on a quartz and indium-tin oxide (ITO) glass substrate. The ultraviolet-visible
(UV-vis) absorption spectra demonstrated that the electrostatically self-assembled film of (BW11Zn/RhB)n was uniformly deposited layer by layer, and the RhB molecules in the film formed the J-aggregation. The photoelectrochemical investigations showed that
the films generated stable cathodic photocurrents that originated from RhB, and the maximal cathodic photocurrent density generated by an eight-layer film was 4.9 μA/cm2 while the film was irradiated with 100 mW/cm2 polychromatic light of 730 nm > λ
> 325 nm at an applied potential of 0 V versus a saturated calomel electrode.
Near-Infrared Quantum Cutting for Solar Cells in Ce3+-Yb3+ Co-Doped CaF2 Nanoparticles
Authors: Li Suwen , Huang Qingqing , Jiang Yi , Hu Min
Published: April 2016

A series of Ce3+-Yb3+ co-doped CaF2 nanoparticles were prepared by a hydrothermal synthesis method. The structure, morphology, photoluminescence properties, and fluorescence dynamics were studied systemically. Under the excitation of the 5d level of
Ce3+, an efficient energy transfer from Ce3+ to Yb3+ occurred, and the efficient near-infrared emission at 900–1050 nm matching to the energy of Si band gap of Si-based solar cells was observed. The lifetime of Ce3+ decreased, and the inner
quantum efficiency increased with increasing Yb3+ concentration. The quantum efficiency dependent on Yb3+ concentration was calculated, and the maximum efficiency approached 186%. As a down-conversion luminescent convertor, this kind of material can be used in front of
Si-based solar cells to reduce thermalization loss and enhance conversion efficiency of solar cells.
Improved Upconversion Luminescence in Water-Soluble Yb3+/Er3+ Codoped LaF3 Nanoparticles Through Ca2+ Doping
Authors: Liu Shihu , Zhang Peng , Li Daguang , Lan Min , Wang Zhe , Qin Weiping , Zhao Dan , Wang Lili
Published: April 2016

Monodisperse water-soluble LaF3: Yb3+/Er3+ nanocrystals (NCs) have been successfully fabricated via a fast, facile, and environmentally-friendly polyol process with polyvinylpyrrolidone (PVP) as an amphiphilic surfactant. The obtained NCs with a small
size of 18 nm can be well dispersed in hydrophilic solutions. Meanwhile, their upconversion (UC) luminescence intensity was increased through Ca2+ doping due to the decrease of symmetry around rare earth ions.
Luminescence Properties of Self-Activated M3(VO4)2 (M = Mg, Ca, Sr, and Ba) Phosphors Synthesized by Solid-State Reaction Method
Authors: Min Xin , Huang Zhaohui , Fang Minghao , Liu Yan’gai , Tang Chao , Wu Xiaowen
Published: April 2016

In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy.
The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm
and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence
lifetimes and quantum yield decrease with the increasing unit cell volume and V–V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the
increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs).
Near-Infrared Downconversion in LuPO4: Tm3+, Yb3+ Phosphors
Authors: Li Li , Wang Yongjie , Shen Jun , Chang Wenxuan , Jin Tianting , Wei Xiantao , Tian Ya
Published: April 2016

Tm3+ and Yb3+ codoped LuPO4 phosphors were synthesized by the reverse-strike co-precipitation method. The obtained LuPO4:Tm3+, Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra,
photoluminescence (PL) spectra, and decay lifetime to understand the observed near-infrared downconversion (DC) phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of LuPO4 and exhibit good crystallinity. The experimental
results showed that the strong visible emission around 649 nm from Tm3+(1G4 → 3F4) and near-infrared (NIR) emission around 1003 nm from Yb3+(2F5/2 → 2F7/2) of LuPO4:Tm3+,
Yb3+ phosphors were observed under 468 nm excitation, respectively. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches
30 mol%. The DC mechanism is also discussed in detail.
Preparation and Optical Properties of Y2O3:Tb3+ Nanoballs
Authors: Yu Hongquan , Qi Ye , Wu Yanbo , Zhang Jinsu , Chen Baojiu
Published: April 2016

Y2O3:Tb3+ nanoballs were synthesized via the urea homogeneous precipitation method (UPM). The resulting Y2O3:Tb3+ phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy, ultraviolet-visible
(UV-vis) absorption spectra, and general photoluminescence spectra. The particle sizes estimated using X-ray diffractometry and scanning electron microcopy were about 50–200 nm. The emission intensity of the Y2O3:Tb3+ was low when the doping concentrations
of Tb3+ were higher. The optimum concentration of Tb3+ for synthesis of Y2O3:Tb3+ nanocrystals is 1%.
Upconversion Luminescence Properties of Y2Mo4O15: Yb3+, Er3+ by Solid State Combustion Method
Authors: Jiang Tao , Xing Mingming , Fu Yao , Tian Ying , Luo Xixian
Published: April 2016

The Yb3+ and Er3+ co-doped yttrium molybdenum oxide upconversion phosphors were prepared by the solid state combustion method using urea as fuel at ignition temperature of 550 °C. The upconversion phosphors were characterized by X-ray diffraction (XRD), scanning
electronic microscope (SEM), and photoluminescence spectra. XRD results revealed the samples were pure monoclinic Y2Mo4O15 phases when the sintering temperature was 700 °C. SEM micrographs illustrated particle size distribution was almost uniform with an
average particle diameter of about 0.5–1.0 m. The obtained Y2Mo4O15:Yb3+, Er3+ presents bright and pure green upconversion luminescence during daylight pumping under 980 nm LD. According to the analysis of upconversion luminescent
mechanism, the cross relaxation processes of Er3+ ions restrained the electron population of red emission energy level, which not only increased the green light upconversion emissions fluorescent branching ratio (IG:IR = 153:1) but
also enhanced the efficiency and purity of green light emissions.
Upconversion Luminescence Properties of Er3+ Doped Yb2Ti2O7 Nanophosphor by Gd3+ Codoping
Authors: Cao B. S , Wu J. L , Wang X. H , Feng Z. Q , Dong B
Published: April 2016

Er3+ doped Yb2Ti2O7 nanophosphors by Gd3+ codoping with nominal composition of (Er0.05Yb0.95−xGdx)2Ti2O7 (x = 0, 0.2, 0.4, 0.6, 0.8, and 0.95)
have been prepared by sol–gel method. −Er3+–Gd3+ codoped Yb2Ti2O7 was characteristic of a typical face-centered cubic crystal phase, and the unit cell parameter increased linearly with the increase of Gd3+
concentration. Under a 976 nm laser diode excitation, both green and red upconversion emissions were observed and the upconversion emissions were enhanced significantly by Gd3+ codoping, showing the strongest green and red emissions at 80 mol% Gd3+ codoping. The intensity
ratio of green to red emissions (Igreen/Ired) increased monotonously with the increase of Gd3+ concentration. The energy transfer between Yb3+ and Er3+ and the variation of local crystal field symmetry of Er3+ by the substitution of Yb3+
by Gd3+ ions led to the improvement of upconversion properties of Er3+–Gd3+ codoped Yb2Ti2O7 nanophosphors.
Optical Temperature Sensing Behavior Through Stark Sublevels Transitions of Green and Red Upconversion Emissions for Er3+–Yb3+–Li+ Codoped TiO2 Phosphors
Authors: He Y. Y , Wu J. L , Wang X. H , Feng Z. Q , Dong B
Published: April 2016

The Er3+–Yb3+–Li+ codoped TiO2 phosphors have been prepared by sol–gel method. The green and red upconversion emissions were observed under a 976 nm laser diode excitation, which were ascribed to 2H11/2→4I15/2,
4S3/2(I)/4S3/2(II)→4I15/2, and 4F9/2(I)/4F9/(2II)→4I15/2 transitions of Er3+ Stark sublevels. The fluorescence intensity ratios (FIR), which
are corresponding to the transitions of 2H11/2/(4S3/2(I)+4S3/2(II)→4I15/2, 4S3/2(I)/4S3/(2II)→4I15/2, and 4F9/2(I)/4F9/2(II)→4I15/2,
have been studied as a function of temperature in the range of 303 ∼ 673 K. The temperature sensitivities have been calculated at the maximum value of 0.0020 K-1, 0.0015 K-1, and 0.0011 K-1 at the temperatures of 427 K, 350 K, and 273 K for the three coupled
energy level transitions, respectively. The Er3+–Yb3+–Li+ codoped TiO2 phosphor with different temperature sensitivities by Stark sublevels indicated that it is a promising material for application in optical temperature sensing at a
wide range of temperature.
Synthesis and Luminescence Studies of Sm3+ Doped Ca9Y(PO4)7 Orange-Red-Emitting Phosphor
Authors: Huang Jun , Yi Shuangping , Deng Yaomin , Zhao Weiren , Xian Jieqiang
Published: April 2016

Ca9Y(PO4)7:Sm3+ phosphor was prepared via solid state reaction. The crystal structure of the phosphor was characterized by X-ray powder diffraction (XRD). The photoluminescence (PL) properties of Ca9Y(PO4)7:Sm3+
were investigated. The emission of the Ca9Y(PO4)7:Sm3+ phosphor consisted of some sharp emission peaks of Sm3+ centered at 563 nm, 600 nm, and 647 nm. The strongest one is located at 600 nm due to the 4G5/2–6H7/2
transition of Sm3+. The critical distance was calculated to be 10.5 Å. The chromatic properties of the sample Ca9Y(PO4)7:Sm3+ phosphor were located in the orange reddish region. The Ca9Y(PO4)7:Sm3+
phosphor may be potentially used as red phosphor for white light-emitting diodes (WLED).
The Size Confinement Effect for Eu3+ Concentration Quenching and Energy Transfer in YVO4 Nanocrystal
Authors: Meng Qingyu , Dai Jiaqi , Sun Wenjun , Wang Changwen
Published: April 2016

YVO4:Eu3+ nanocrystal powders (∼30 nm) with different doping concentrations were prepared using a precipitation method. Bulky powders (∼500 nm) were obtained by annealing the nanopowders at high temperature. The concentration quenching of luminescent centers and energy
transfer in YVO4: Eu3+ powders were investigated. It was found that quenching concentration for Eu3+ 5D0→7F2 transition emission in nanopowders is distinctly higher than that in bulk powders. The type of energy
transfer that caused concentration quenching was identified to be electric dipole–dipole interaction in bulk powders and exchange interaction in nanopowders. The electric dipole–dipole interaction is a long-range interaction (operating range of several nanometers). The size confinement
effect of boundary in nanoparticles has obvious inhibitory effect on electric dipole–dipole interaction, and hardly affect the exchange interaction which is a short-range interaction (operating range several angstroms). The electric dipole–dipole interaction is restrained by particle
boundary in nanopowders. So energy transfer of Eu3+ ions in nanomaterials is dominated by exchange interaction, and quenching concentration of nanomaterials is higher than in bulky materials.
Study on Nonlinear Absorption Effect of Nanosecond Pulse Laser Irradiation for GaAs
Authors: Sun Wenjun , Liu Zhongyang , Zhou Haijiao
Published: April 2016

In order to research nonlinear absorption effect of pulse laser irradiation for GaAs, a physical model of Gaussian distribution pulse laser irradiation for semiconductor material was established by software COMSOL Multiphysics. The thermal effects of semiconductor material GaAs was
analyzed under irradiation of nanosecond pulse laser with wavelength of 1064 nm. The radial and transverse temperature distribution of semiconductor material GaAs was calculated under irradiation of nanosecond pulse laser with different power density by solving the thermal conduction equations.
The contribution of one-photon absorption, two-photon absorption and free carrier absorption to temperature of GaAs material were discussed. The results show that when the pulse laser power density rises to 1010 W/cm2, free carrier absorption played a leading role and
it was more than that of one-photon absorption of material. The temperature contribution of two-photon absorption and free carrier absorption could be ignored at laser power density lower than 108 W/cm2.The result is basically consistent with relevant experiments, which
shows that physical model constructed is valid.
Effect of Tourmaline-Doped on the Far Infrared Emission of Iron Ore Tailings Ceramics
Authors: Liu Jie , Meng Junping , Liang Jinsheng , Zhang Hongchen , Gu Xiaoyang
Published: April 2016

Iron ore tailings as secondary resources have been of great importance to many countries in the world. Their compositions are similar to that of infrared emission ceramics, but there are few reports about it. In addition, tourmaline has high infrared emission properties due to its unique
structure. With the purpose of expanding functional utilization of iron ore tailings, as well as reducing the production cost of far infrared ceramics, a new kind of far infrared emission ceramics was prepared by using iron ore tailings, calcium carbonate, silica, and natural tourmaline. The
ceramics powders were characterized by Fourier transform infrared spectroscope, X-ray diffraction and scanning electron microscopy, respectively. The results show that after being sintered at 1065 °C, the percentage of pseudobrookite and lattice strain of samples increased with increasing
the elbaite content. Furthermore, the added tourmaline was conducive to the densification sintering of ceramics. The appearance of Li–O vibration at 734.73 cm−1, as well as the strengthened Fe–O vibration at 987.68 cm−1 were attributed to the formation
of Li0.375Fe1.23Ti1.4O5 solid solution, which led the average far infrared emissivity of ceramics increase from 0.861 to 0.906 within 8–14 μm.
Synthesis and Luminescent Properties of Eu2+ Doped Sr5SiO4Cl6 Phosphor by Sol–Gel Method
Authors: Li Xu , Zhang Huaye , Tang Aiwei , Guan Li , Guo Zhen , Yuan Kunsheng , Tie Licheng , Dong Guoyi , Yang Zhiping , Teng Feng
Published: April 2016

The paper discusses preparation and luminescent properties of Sr5SiO4Cl6:Eu2+ blue phosphor, which was synthesized by sol–gel method. The emission and excitation spectra, SEM, XRD and diffuse reflection of the fluorescent powder were
measured. It was shown that the samples were single phase of Sr5SiO4Cl6 by the XRD patterns. The photoluminescence and excitation spectra of this phosphor were investigated. The phosphor excited by 278 nm light showed an asymmetric spectrum. The emission spectra
can be separated into three distinct peaks located at 450, 480 and 540 nm, respectively. The influences of Eu2+ ions concentration on the emission intensity of Sr5SiO4Cl6:Eu2+ phosphors were studied in detail. The influences of different
sintering temperature on the emission intensity were also investigated. The optimal sintering temperature was 750 °C. Effects of the amount of complexing agent were studied and a ratio of 1∼1.1 to that of the cation was the best. The particle diameter of the phosphor was studied by
SEM. The potential applications were also discussed.
Hydrothermal Synthesis and Luminescent Properties of Eu3+ Doped Sr3Al2O6 Phosphor for White LED
Authors: Li Xu , Pan Heng , Tang Aiwei , Zhang Jinping , Guan Li , Su Hongxin , Dong Guoyi , Yang Zhiping , Wang Huike , Teng Feng
Published: April 2016

Eu3+ ions doped Sr3Al2O6 phosphors were successfully synthesized via a hydrothermal method. The precursor was prepared by low temperature hydrothermal method using ammonia as both alkaline source and precipitator. Then the final product was
obtained by high temperature sintering. In addition, the structures, morphologies, and luminescent properties of as-prepared products were thoroughly characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fluorescence spectroscopy (PL). XRD shown a single phase
Sr3Al2O6 prepared by a facile hydrothermal method at 250 °C for 10 h. In the PL spectra of as-prepared samples, the optimal value of Eu3+ concentration is 2 mol%. From the fluorescent spectra, the emission peaks of Sr3Al2O6:
Eu3+ phosphors are centered at around 591 nm, and the excitation peaks are centered at around 233 nm, 323 nm, 394 nm, and 468 nm, respectively, which were assigned to the characteristic transition of Eu3+ ions. The influence of ammonia, and the synthesis temperature on
the luminescent properties of Sr3Al2O6: Eu3+ phosphors were studied in detail. The alkaline earth aluminates luminescent materials activated by rare earth ions have good prospects in the field of new-generation light sources.
Synthesis, Characterization and Novel Photoluminescence of SrWO4:Ln3+ Nanocrystals
Authors: Xu Bingyu , Li Mingxia , Pan Kai , Li Rong , Fan Naiying , Wang Guofeng
Published: April 2016

SrWO4:Ln3+ (Ln = Eu, Ce, and Tb) nanocrystals were successfully synthesized by a hydrothermal method, and were characterized by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The results indicated that the crystalline size
of nanocrystals decreases with increasing Eu3+ concentrations and increases with increasing annealing temperature, gradually. The photoluminescence properties of SrWO4:Ln3+ were investigated in detail. In the emission spectra of SrWO4:Eu3+,
the luminescence was dominated by 5D0 → 7F2 transition, indicating that Eu3+ occupied a site lacking inversion symmetry. The concentration quenching effect hardly occurs. In the excitation spectra of SrWO4:Eu3+
nanocrystals monitored at 619 nm, the most intense peak is centered at 467 nm when the Eu3+ concentration was less than 10%, while the most intense peak is centered at 396 nm when the Eu3+ concentration was 15%. In the normalized emission spectra of SrWO4:Ce3+/Tb3+
nanocrystals excited at 254 nm, the intensity ratio of the sharp emission peaks from Tb3+ ions to the broad emission band from Ce3+ ions increased with increasing Tb3+ concentration.
PbS Quantum Dots Sensitized TiO2 Solar Cells Prepared by Successive Ionic Layer Absorption and Reaction with Different Adsorption Layers
Authors: Yi Jie , Duan Yanfang , Liu Chunxia , Gao Shaohong , Han Xueting , An Limin
Published: April 2016

Lead sulfide (PbS) quantum dots (QDs) have been synthesized via successive ionic layer adsorption and reaction (SILAR) on a titanium dioxide (TiO2 nanoporous film for the fabrication of quantum dot-sensitized solar cells (QDSCs). The reaction is environmental friendly and
energy saving. The green synthesized PbS QDs match the maximum remittance region of the solar spectrum and are suitable as sensitizers for TiO2 electrodes for cell devices application. PbS QDs were adsorbed in different adsorption layers in order to improve the solar cell performance.
The optical properties of PbS sensitized TiO2 films were studied by scanning electron microscopy and UV-Vis absorbance spectroscopy. The photovoltaic characteristics of the PbS QDSCs were analyzed by I–V characteristics and electrochemical impedance spectroscopy. As
a result, the light harvesting was enhanced with increasing SILAR adsorption layers. The maximum photovoltaic conversion efficiency of the PbS QDSCs (3.14%) was obtained at the 12 adsorption layers with the highest short circuit current density and lowest charge transfer resistance.
Photoluminescence and Photocatalytic Activity of Bi2MoO6:Ln3+ Nanocrystals
Authors: Feng Li , Li Mingxia , Pan Kai , Li Rong , Fan Naiying , Wang Guofeng
Published: April 2016

Sheet-like Bi2MoO6:Ln3+ nanocrystals were synthesized by a hydrothermal method. The crystalline size of Bi2MoO6:Ln3+ (Ln = Eu and Gd) nanocrystals changes gradually with the increasing of Ln3+ content in the
reaction solutions. The photoluminescence properties of Bi2MoO6:Ln3+ nanocrystals were investigated in detail. In the emission spectra of Bi2MoO6:Eu3+ nanocrystals the 5D0 →7F2
is much stronger than the 5D0 →7F1 and is the strongest when the excitation is performed at 467 nm. The relative intensity of the transitions from Eu3+ increased with increasing Eu3+ concentrations, up to about 50 mol%,
and then decreased abruptly. In the excitation spectra of Bi2MoO6:Eu3+ (30%)/Gd3+ monitored at 618 nm, the 7F0 → 5D2 (∼467 nm) transition is dominating when the Gd3+ concentrations were
10% or 20%. When the Gd3+ concentration was 30%, the 7F0 → 5D1 (∼538 nm) transition is dominating. In addition, the photocatalytic activity of Bi2MoO6:Eu3+ was evaluated by the degradation of rhodamine
B (RhB) aqueous solution under simulated solar light. The best photocatalytic performance was observed when the Eu3+ concentration was 1%.
Synthesis and Photoluminescence of Rhombic NaLa(MoO4)2:Ln3+ Nanocrystals
Authors: Wang Yuping , Li Mingxia , Pan Kai , Li Rong , Fan Naiying , Wang Guofeng
Published: April 2016

Rhombic NaLa(MoO4)2:Ln3+ (Ln = Eu and Tb) nanocrystals were synthesized by a hydrothermal method. The structures and morphologies of the nanocrystals were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results
indicated that the crystalline size increased with increasing Na2MoO4 content. The photoluminescence properties of NaLa(MoO4)2:Ln3+ nanocrystals were investigated in detail. In the emission spectra of NaLa(MoO4)2:Eu3+
nanocrystals, the 5D0 → 7F2 is dominant, and the peak positions and spectral shapes of emissions were independent of Eu3+ concentration. The luminescence intensity increased with increasing Eu3+ concentration, up to about
10 mol%, and then decreased. In the emission spectra of NaLa(MoO4)2:Tb3+ nanocrystals, the 5D4 → 7F5 is dominant. The sample with a dopant concentration of 20 mol% showed the highest emission intensity.
Activities of Combined TiO2 Semiconductor Nanocatalysts Under Solar Light on the Reduction of CO2
Authors: Liu Hongfang , Dao Anh Quang , Fu Chaoyang
Published: April 2016

The materials based on TiO2 semiconductors are a promising option for electro-photocatalytic systems working as solar energy low-carbon fuels exchanger. These materials’ structures are modified by doping metals and metal oxides, by metal sulfides sensitization, or
by graphene supported membrane, enhancing their catalytic activity. The basic phenomenon of CO2 reduction to CH4 on Pd modified TiO2 under UV irradiation could be enhanced by Pd, or RuO2 co-doped TiO2. Sensitization with metal sulfide
QDs is effective by moving of photo-excited electron from QDs to TiO2 particles. Based on characteristics of the catalysts various combinations of catalysts are proposed in order to creat catalyst systems with good CO2 reduction efficiency. From this critical review of
the CO2 reduction to organic compounds by converting solar light and CO2 to storable fuels it is clear that more studies are still attractive and needed.
Preparation and Photovoltaic Properties of Dye Sensitized Solar Cells Using ZnO Nanorods Stacking Films on AZO Substrate as Photoanode
Authors: Xu Yang , Wang Xina , Liu Rong , Wang Hao
Published: April 2016

Three-dimensional stacking of ZnO nanorods on conducting aluminum-doped ZnO (AZO) glass were studied as efficient photoanodes of dye sensitized solar cells (DSSCs). By changing hydrothermal growth time and cycle times, the thickness of ZnO nanorods stacking films varied from 30 μm
to 64 μm, and its influence on the energetic conversion efficiency of the DSSCs based on the stacking films photoanodes was investigated. The loading density of N719 on the surface of ZnO nanorods was studied to increase the efficiency of the cells. Annealing experiments showed that
the AZO substrates remained good conductors until heated above 350 °C. A photoelectric conversion efficiency as high as ∼2.0% together with Isc of ∼9.5 mA/cm2, Voc of ∼0.5 V and FF of ∼41.4% was achieved for the DSSC using 50 μm-thick
film stacking by ZnO nanorods as photoanode and N719 as sensitizer under illumination of AM1.5G solar light (power density of 100 mW/cm2). A charge separation and transfer mechanism was proposed for the ZnO nanorods stacking electrode-based DSSCs.
Synthesis and Characteristic of the NaYF4/Fe3O4@SiO2@Tb(DBM)3 · 2H2O/SiO2 Luminomagnetic Microspheres with Core–Shell Structure
Authors: Yu Shiyong , Zhang Renfei , Zhao Jing , Gao Xuechuan , Li Zhao , Tan Zhibing , Su Haiquan
Published: April 2016

The structure and properties of the multifunctional nanoparticles were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Photoluminescence spectra and Vibrating sample magnetometer (VSM). The experimental
results show that the microsphere has the magnetic core and silica shell bonded with terbium complex. These multifunctional nanoparticles exhibit strong visible emission and up-conversion emission, which is based on the use of up-converting nanoparticles (UCNPs) of the NaYF4:Yb3+,
Er3+/Tm3+ type that can be excited with 980 nm laser light to give a green and red luminescence, moreover, nanoparticles possess magnetism with a saturation magnetization of 18.48 emu/g and paramagnetism at room temperature.
Self-Assembled NaTb1−x Eux(MoO4)2: Synthesis and Luminescence Properties
Authors: Liu Xiaoqing , Qu Lingnan , Wang Shuo , Li Lv , Su Yiguo , Wang Xiaojing
Published: April 2016

Novel 3D Eu3+ doped NaTb(MoO4)2 composites were successfully self-assembled by a facile hydrothermal treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectra were
used to characterize the structures, morphologies and the luminescent properties of as-prepared products. Emission and excitation spectra showed that the phosphor exhibits a dominant red emission at 615 nm with excitation wavelength of 465 nm at room temperature. The emission intensity increased
with the increase of Eu3+ concentrations for the investigated range of 2–10 mol% Eu3+ doping in NaTb(MoO4)2. The doping of Eu3+ results in a distorted Eu–O8 cluster and enhanced luminescence intensity.
Gain Characteristics of Polymer Waveguide Amplifiers Based on NaYF4:Yb3+, Er3+ Nanocrystals at 0.54 μm Wavelength
Authors: Zhang Meiling , Yin Jiao , Jia Zhixu , Song Weiye , Wang Xibin , Qin Guanshi , Zhao Dan , Qin Weiping , Wang Fei , Zhang Daming
Published: April 2016

Gain characteristics of polymer waveguide amplifiers based on NaYF4:Yb3+, Er3+ nanocrystals (NCs) at 0.54 μm wavelength were investigated through numerical simulations. NaYF4:18%Yb3+, 10%Er3+ NCs were doped
into SU-8 2005 polymer matrix as the core of a polymer waveguide. The absorption spectrum and photoluminescence spectrum of the NCs were recorded and analyzed. The Judd-Ofelt parameters were achieved by means of Judd-Ofelt theory: Ω2 = 6.302×10−20 cm2,
Ω4 = 0.69×10−20 cm2, Ω6 = 7.572×10−20 cm2. We simulated the gain characteristics of the waveguide amplifier at 0.54 μm wavelength by combining the atomic rate equations with power
propagation equations. The gain curves had the saturation effects. A maximum gain ∼4.3 dB for the 5 cm waveguide with the Er3+ concentration of ∼7.5×1025 m−3 was obtained.
Optical Limiting Properties of Graphene/Polymer Composites
Authors: Pan Ruiyi , Guo Jin , Wang Tingfeng , Shao Junfeng , Wang Dong , Zhang Qiuping , Wang Yan , Tang Jun
Published: April 2016

Graphene oxide (GO) was doped into four polymers films: Poly(methyl methacrylate) (PMMA), polystyrene (PS), polycarbonate (PC), and polyacrylonitrile (PAN). Following that, their optical limiting properties were investigated at 532 nm. In order to make GO hydrophobic, the lipophilic
alkyl chains were connected to GO. The results showed that GO/PAN composite possesses better non-linear response than the other three composites at the same transmission (T ≈ 59%). The reason were attributed to the thermal effect coming from high input fluence of laser, which
improved the cross link density of PAN and further enhanced the interaction between the GO-ODA and PAN. Meanwhile, GO/PC and GO/PS had similar optical limiting property and GO/PMMA film gave the weakest optical limiting effect in our experiment.
Hydrothermal Synthesis and Multicolor Upconversion Fluorescence of Novel LiLuF4:Yb3+, Tm3+ Microcrystals
Authors: Chuai Xiaohong , Zhang Xiang , Bi Xueqing , He Chunfeng , Qin Weiping
Published: April 2016

LiLuF4:Yb3+, Tm3+ upconversion luminescence materials were synthesized by a hydrothermal method, in which NaF and NaBF4 were used as fluorine sources (labeled as sample A and B, respectively). Their morphologies, XRD patterns and UC emission
properties were compared. The synthesized crystallites consist of regular octahedrons of several micrometers and aggregates. The XRD patterns indicate that they belong to tetragonal crystal system with I41/a space group. These microcrystals emit strong UC violet, visible and near
infrared light under the excitation of 980 nm laser diode. The multicolor UC emissions from sample B are much stronger than those from sample A. The strong emission intensity is ascribed to good crystal quality of sample B.
Morphology Controllable Synthesis of ScF3:Er3+, Yb3+ Nano/Sub-Microncrystals by Hydrothermal/Solvothermal Process
Authors: Han Lili , Li Hua , Ci Zhipeng , Wang Yuhua
Published: April 2016

In this paper, red phosphors Yb3+–Er3+ co-doped ScF3 nano/microcrystals were successfully prepared by a facile hydrothermal/solvothermal route using the sodium dodecyl benzene sulfonate (SDBS) as the surfactant. The structure, morphologies and
up-conversion (UC) photoluminescence properties of the as-prepared products were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectra, respectively. The SEM images show that the obtained samples are the uniform cubic and cuboid
crystals. With the increase of the surfactant SDBS or the change in the solvent types, the sample change their size from nanometer to submicron. Upon the 980 nm laser diode excitation, the ScF3:Er3+, Yb3+ nanocrystals exhibit red emission which can be assigned
to the characteristic 4F9/2/4I15/2 transition of Er3+. In order to understand the emission mechanisms of ScF3:Er3+, Yb3+ nanocrystals, the dependence of UC luminescence intensity on the 980 nm excitation
power was measured, suggesting that the UC phenomenon results from a two-photon process. Meanwhile, the emission intensities of the Yb3+–Er3+ codoped ScF3 nano/sub-micro crystals with different solution composition show an obvious change under the 980
nm laser excitation. Therefore, the phosphors Yb3+–Er3+ co-doped ScF3 possibly have a potential application in the biological applications.
Influence of Pt and Pd Modification on the Visible Light Photocatalytic Activity of N-Doped Titania Photocatalysts
Authors: Hu Yulong , Dong Fu , Liu Hongfang , Guo Xingpeng
Published: April 2016

Pd and Pt modified N-doped titania nanoparticle powders were prepared by a facile sol–gel method. Nitrogen doping and metal modification were carried out simultaneously during the preparation process. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission
electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and X-ray photoelectron spectroscopy (XPS). The visible light photocatalytic activities of the asprepared samples were evaluated by analyzing their effect on the photocatalytic decomposition
of methyl orange (MO). The chemical state of the metal is the key factor determining the performance of metal modified N-doped titania. The Pd used to modify the N-doped titania (Pd-NT) in our study was of the PdOx(x≤2) species, which increased the absorbance in the visible light
region, decreased the recombination of photo-generated electron–hole pairs, and resulted in a significant enhancement in the visible light photocatalytic activity. The Pt species used to modify the N-doped titania (Pt-NT) was mainly in the metallic state, which resulted in a decrease
in the absorbance in the visible light region, and an increase in the recombination of photo-generated electron–hole pairs. Pt modification led to a deterioration in the visible light photocatalytic activity of the material.