最新刊期
卷 35 ， 期 3 ， 2014
- 摘要：To extend the application of dye-doped polymer fibers, polymethyl methacrylate (PMMA) rods doped with Coumarin 540 and Rhodamine 6G laser dyes were synthesized with methyl methacrylate (MMA), and drawn to fibers with 1 000 μm diameters. The fluorescence and fluorescence transmission loss of the dyes and the spectral down-conversion properties of the dye-doped polymer fibers were studied under side illumination and front surface illumination conditions, where a commercial LED lamp was used as illumination source. The Stokes shifts of these two dyes doped in PMMA matrix were found to be 70 nm and 50 nm, respectively. Under side-illumination condition, 0.01 mg/g and 0.04 mg/g dopant concentrations, the transmission loss of the fibers for 520 nm and 577 nm fluorescence were determined to be 0.336 cm-1 and 0.343 cm-1, respectively. Under front surface illumination condition, the down-converted spectral outputs from the end of the fibers were observed with high conversion efficiency which was relative with dye concentration and fiber length. The dye-doped polymer fibers are possible coupled with silica fibers to modify the frequencies of the light transmitted by the silica fibers to better satisfy different application requirements.关键词：fluorescence;absorption;spectral down-conversion;dye-doped;polymer optical fiber108|169|0更新时间：2020-08-12
- 摘要：Coating the nanoparticles with a homogeneous shell is a feasible strategy to reduce energy losses on the nanoparticle surface. Eu3+ doped hexagonal LaF3 nanoparticles with a mean size of 7~8 nm were prepared by co-precipitation method. After coating the LaF3:Eu3+ core particles with the undoped LaF3, the enhancement of Eu3+ emission in LaF3:Eu3+/LaF3 core-shell nanoparticles was discovered. In comparison with the LaF3:Eu3+ core, the luminescence lifetime of Eu3+ emission in core-shell nanoparticles was increased. The decay curves of LaF3:Eu3+/LaF3 core/shell nanoparticles with different thickness had also been studied. The increase of the luminescence lifetime of Eu3+ emission resulted from the effective shielding of the luminescence center Eu3+ ions from LaF3:Eu3+ core, the quenching at or near the surface of the nanoparticles was reduced.关键词：LaF3：Eu3+;core-shell structure;homogeneous coating;nanoparticles93|96|1更新时间：2020-08-12
- 摘要：Al18B4O33:Cr3+ phosphor was prepared by solid-state reaction method. The samples were characterized by X-ray diffraction, FSEM, reflectance spectra, fluorescence emission and excitation spectra. The results show that the samples can be excited by UV light and green-orange light in the range of 530~630 nm and show deep red emission at 660~720 nm. Two emission peaks are observed at 683 nm and 694 nm, the maximum excitation wavelength is 590 nm. When the initial molar ratio is n(Al)/n(B)=3.5, the sample gives the strongest emission. The effect of H3BO3 on fluorescence of the phosphor is briefly discussed. The optimized sintered temperature is 1 150 ℃. The fluorescence intensity of the phosphor increases with the Cr3+-doping concentration, and the fluorescence efficiency decreases with Cr3+-doping concentration. The reflectance spectra show that the samples have strong absorption in both UV and yellow-orange region and have a promising prospect in the light conversion material for agricultural applications.关键词：solid-state reaction method;sunlight-conversion agent;Al18B4O33：Cr3+118|129|1更新时间：2020-08-12
- 摘要：Erbium (Ⅲ)/ytterbium (Ⅲ)-codoped tellurite glass has been widely studied due to its good quality of up-conversion emission. In this work, fluoride was introduced in the tellurite glass and a series of glasses 70TeO2-(30-x)ZnO-xZnF2-0.15Er2O3-1.5Yb2O3(x=0, 5, 10, 15, 20, molar ratio) were prepared via melting process. The thermal stabilities were tested by DTA-TG, and the Raman spectra and stimulated emission spectra were obtained. The results show that the up-conversion luminescence of 410, 555, 670 nm and mid-infrared emission in the range of 2~3 μm are enhanced with the increasing fluoride content, and the red light at 670 nm get more greatly enhanced. We analyzed the intrinsic impact mechanism of fluoride ions on the up-conversion and infrared luminescence and drew the following conclusions: fluoride in tellurite glass could promote the two-photon absorption process of erbium ions, thereby promoting the particles transition to appropriate high-energy level; on the other hand, the maximum phonon density of glass decreased with the introduction of fluoride, which reduced non-radiative transition probabilities and thus improved the conversion and mid-infrared emission intensity.关键词：Er3+/Yb3+ codoped;up-conversion;mid-infrared emission;oxyfluoride tellurite glass102|147|4更新时间：2020-08-12
- 摘要：The hexagonal β-NaYF4:Yb,Tm particles and core-shell structure β-NaYF4:Yb,Tm@β-NaYF4:Yb particles were prepared by solvothermal method. The as-prepared particles were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and photoluminescence (PL) spectra. With the increasing of Yb3+ concentration, the luminus intensity of β-NaYF4:Yb,Tm particle first increases, then decreases. When the mole fraction of Yb3+ is 30%, the intensities of 474, 645 nm reach the maximum, and when the mole fraction of Yb3+ is 50%, the intensities of 450, 692 nm reach the maximum. Then β-NaYF4:30% Yb,Tm particls were coated by β-NaYF4:Yb layer. When the mole fraction of Yb3+ in shell layer is 10%, the luminus intensity of β-NaYF4:Yb,Tm@β-NaYF4:Yb particle is the maximum. The luminus intensities of all the samples increase after heat treatment, and the blue luminus intensity decreases and red luminus intensity increases with the increasing of ambient temperature. The transparent composite materials of β-NaYF4:Yb,Tm and PMMA were synthesized by in situ polymerization, and showed good luminescence property.关键词：upconversion luminescence;doping concentration;core-shell;NaYF492|25|0更新时间：2020-08-12
- 摘要：A novel near-infrared afterglow material Zn3Al2Ge2O10:Cr3+ was synthesized by high-temperature solid-phase method, and analyzed by means of XRD, photoluminescence spectra, curve of afterglow decay, etc. The results indicate that the Zn3Al2Ge2O10:Cr3+ is in fact ZnAl2O4:Cr3+ spinel compound in which Al3+ is partly replaced by Ge4+. Under 397 nm excitation, the emission spectra at room temperature mainly consist of two obvious narrow peaks superposition on a broadband which belongs to the spin-allowed 4T2→4A2 emission of Cr3+. The concentration quenching and temperature quenching could be observed as the Cr3+ doping concentration and sintering temperature increasing. The optimized LLP performance and the strongest luminescence intensity could be obtained when the doping content of Cr3+(x) in Zn3Al2－xGe2O10:xCr3+ is 2% and the sintering temperature is 1 350 ℃. The persistence time of the material lasts more than 300 h. The strongest peaks of both emission spectrum and afterglow spectrum are at around 697 nm. The effect of sintering temperature on the LLP performance is analyzed and the mechanism of super long afterglow is researched.关键词：near-infrared long-lasting;Zn3Al2Ge2O10：Cr3+;concentration quenching;anti-site defect144|291|5更新时间：2020-08-12
- 摘要：By using a simple and mild two-step water-bath method, a large area of flower-like self-supporting Ag-doped ZnO nanoarrays were fabricated. Field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectrometer (EDS), X-ray diffraction (XRD), room temperature and temperature depend photoluminescence (PL) were used to characterize the morphology, crystalline quality and optical properties of the samples. The emission related to acceptor located at 3.360 eV and 3.315 eV can be observed at low temperature (85 K), and the theoretical calculated acceptor binding energy is 118 meV. In temperature depend PL spectra, the calculated values of FA emission agree well with the theoretical model.关键词：water-bath method;self-supporting;flower-like Ag-doped ZnO nanoarrays;optical properties135|191|1更新时间：2020-08-12
- 摘要：Up-conversion luminescence powders were synthesized by high-energy ball-milling (HEB) method and the conventional solid-state reaction (SSR) method. All the phosphors were sintered at 1 100 ℃ for 2 h. X-ray powder diffraction (XRD) shows that the HEB samples have higher phase purity and crystallinity compared with the SSR samples. Excited by 980 nm laser, the HEB samples show higher photoluminescence (PL) intensity. Tm3+, Yb3+co-doped sample emits yellow light,Er3+,Yb3+ co-doped sample emits green light, and the luminous intensity of Tm3+, Er3+, Yb3+ co-doped sample is weaken and the color is tunable.关键词：ball milling;solid-state reaction;up-conversion;luminescence136|210|0更新时间：2020-08-12
- 摘要：The red phosphor Sr3B2O6:Eu3+,Li+ was prepared by high temperature solid-state method. The effects of the concentration of activating agent Eu3+and sensitizing agent Li+ on luminescent properties of Sr3B2O6:Eu3+,Li+ were investigated. The results show that there is not obvious structure transformation of Sr3B2O6 after appropriate amounts of Eu3+ and Li+ doping. The optimal doping content of Eu3+ and Li+ are 4% and 8%, respectively. The optimal temperature is 900 ℃ for 2 h. The phosphor Sr3B2O6:Eu3+,Li+ can be excited by 394 nm near-UV light and emits red light corresponding to the 4f-4f transition of Eu3+. Its strongest emission peak is attributed to the 5D0→ 7F2 transition of Eu3+ at about 614 nm. The phosphor could be a promising red phosphor for white LED.关键词：borate;high temperature solid-state method;phosphor;rare earths;luminescence116|92|10更新时间：2020-08-12
- 摘要：Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films were prepared by using spray coating technique. The morphology, transmittance and conductivity of the film were studied by using ethanol, deionized water, methanol and isopropanol to dilute the origin PEDOT:PSS, respectively. The solvent-diluted PEDOT:PSS films were employed to fabricated organic solar cells. The effect of solvents dilution on the solar cells performance was studied. The results indicate that the introduction of ethanol can effectively inhibit the agglomeration of PEDOT:PSS particles, reduce the film roughness, and improve the transmittance and conductivity of the PEDOT:PSS film. The organic solar cell based on the PEDOT:PSS film diluted with ethanol exhibits a power conversion efficiency of 2.66%, which is higher than those with other diluting solvents.关键词：PEDOT：PSS;spray coating;organic solar cell269|258|4更新时间：2020-08-12
- 摘要：Based on a new framework 7-(9H-carbazol-9-yl)-N,N-diphenyl-9,9'-spirobi[fluoren]-2-amine (CzFA) bipolar host material, the phosphorescent organic light-emitting diodes(PhOLEDs) were fabricated, and the electroluminescence properties of the devices were investigated. The red PhOLEDs doped with iridium (Ⅲ) bis [2-methyldibenzo-(f,h) quinoxaline](acetylacetonate) (Ir(MDQ)2(acac)) show excellent electroluminescence properties, the maximum current efficiency is 27.8 cd/A,and the maximum power efficiency is 21.8 lm/W, which is almost 1.6 times higher than the device with CBP as host material(13.7 lm/W). The bipolar host material composed of carbazole fluorene and 2-amine substituent plays an important role for the performances improvement of the phosphorescent device.关键词：organic light emitting diodes;phosphorescent device;red device112|24|4更新时间：2020-08-12
- 摘要：A laser diode (LD) end pumped acousto-optic Q-switched Nd:YVO4 solid state 355 nm ultraviolet laser is reported by using intra-cavity double frequency and extra-cavity sum frequency technique. Nd:YVO4 crystal bonded by YVO4 in its both sides is end-pumped by LD, and typeⅠphase matched LiB3O5 (LBO) as the second harmonic generation crystal is placed in the cavity. 1 064 nm and 532 nm dual wavelength output from the cavity are coupled into the typeⅡ phase matched LBO crystal through an achromatic lens. High efficiency, good beam quality and high repetition rate 355 nm ultraviolet laser is obtained by sum frequency mixing back and forth. The 4.2 W 355 nm laser is obtained at the pump power of 28.6 W and the repetition frequency of 20 kHz, with the pulse width as short as 20.6 ns. The optical to optical conversion efficiency is about 14.7%. The beam quality factor Mx2 and My2 of 355 nm ultraviolet laser are 1.29 and 1.23, respectively.关键词：diode pumped lasers;355 nm ultraviolet laser;end-pumped;acousto-optic Q-switched;sum frequency mixing114|249|5更新时间：2020-08-12
- 摘要：The all-solution method was employed as a vacuum-free technics to fabricate white light-emitting diodes. The performance of the device was optimized by adding a modified layer and optimizizing the thickness of each layer. ITO was used as the cathode, and PFN film was added to reduce the work function of the cathode. The polymer PFN was also used as the electron injection material and the blue emitter. The polymer MEH-PPV was used as orange emitting layer. By introducing Cs2CO3 as modified layer, the turn-on voltage was reduced and the electron injection ability was improved effectively. The highly conductivity PEDOT:PSS film was employed to replace metal electrode as the anode. The results show that the EL spectra of the device extend from 400 nm to 800 nm, covering the whole visible region, the device starts to glow at 4 V and exhibits a maximum luminance of 1 500 cd/m2 with a maximum current efficiency of 0.55 cd/A.关键词：all-solution method;white light-emitting;PFN;MEH-PPV85|174|0更新时间：2020-08-12
- 摘要：Photoresponsive organic field-effect transistors (phOFETs) were fabricated by utilizing organic heterojunction based on pentacene and lead phthalocyanine (PbPc). Under a near-infrared light illumination (wavelength 808 nm and a power intensity of 124 mW/cm2), the heterojunction photoresponsive organic field-effect transistors (HJ-phOFETs) exhibited a maximum photosensitivity of 4.4×104, and a maximum photoresponsivity of 118 mA/W, which were 766 times and 785 times higher than that of PbPc single-layer phOFET, respectively. It was observed that the maximum photosensitivity and the maximum photoresponsivity stabilized around 5.4×104 and 326 mA/W after 120 h, respectively. The high performance of HJ-phOFET is attributed to the utilization of PbPc as photosensitive layer which has high absorbance in near infrared region (NIR) and pentacene as channel layer with high hole mobility. These results indicate that the HJ-phOFET based on pentacene and PbPc is proved to be a NIR photodetector with excellent photosensitivity and stability.关键词：heterojunction;pentacene;PbPc;near infrared;photoresponsive organic field effect transistor93|84|0更新时间：2020-08-12
- 摘要：N, N-Dipehnyl-N,N-di(m-Tolyl)benzidine (TPD) was used as buffer layer in the organic thin-film transistors (OTFTs) with bottom gate-top contact structure: ITO/PMMA (1 150 nm)/Pentacene (30 nm)/Pentacene:TPD (10 nm, 1:1)/Au. The corresponding hole mobility of the co-doped device increases from (0.1±0.01) cm2/(V·s) to (0.31±0.02) cm2/(V·s), which is nearly 3 times higher than that of the reference device. In addition, the threshold voltage decreases from (－34.6±1.3) V to (－30.1±1.2) V. Atomic force microscope characterization shows that the performance enhancement can be attributed to the roughness amelioration of the interface. The results indicate that TPD is an efficient buffer layer material for OTFTs.关键词：organic thin film transistor;surface morphology;mobility;TPD115|210|1更新时间：2020-08-12
- 摘要：Using Suzuki coupling reaction, a novel blue-emitting anthracene-based derivatives was designed and synthesized by introducing the electron transport branch of oxadiazole derivatives. The optical properties, thermal properties, electrochemical properties, and surface morphology of the compound were characterized. The maximum emission wavelength of this compound is 433 nm in tetrahydrofuran, and the fluorescence quantum yields is 0.94 which is 1.17 times than that of 9,10-di(2-naphthyl)anthracene. The film of this compound is continuous, compact, and smooth after annealing at 100 ℃ for 3 h, which is suitable to prepare long life and high efficiency OLED devices.关键词：OLED;blue-emitting materials;anthracene-based derivatives193|192|3更新时间：2020-08-12
- 摘要：V2O5/Ag/V2O5 (VAV) multi-layer transparent conductive film was prepared by the combination of sol-gel technique and electron beam evaporation at room temperature. The effects of each layer's thickness on photoelectrical properties and surface appearance of multi-layers were studied by atomic force microscope, UV-Vis spectrophotometer, four-point probe method and Kelvin probe. The experiments results reveal that the multi-layer transparent conductive film has desirable photo-electrical properties with average transmission of 75%(380~780 nm), mobility of 16.89 cm2/(V·s), carrier concentration of -1.043×1022 cm-3, the sheet resistance of 15.1 Ω/□, and work function of 5.17 eV. This method reduces the difficulty of fabricating V2O5/Ag/V2O5 multi-layer films, providing a kind of promising transparent electrode for solar cells.关键词：sol-gel technique;transparent conductive film;V2O5/Ag/V2O5 (VAV) multi-layers112|49|1更新时间：2020-08-12
- 摘要：A series of novel rare earth complexes were synthesized with salicylideneglycine schiff base (Sal-GlyK), l,10-phenanthroline (Phen) and 2,2'-bipyridine (Bipy). The complexes were characterized by elemental analysis, rare earth coordination titration, molar conductivity measurement, IR spectroscopy and UV-Vis absorption spectroscopy. They were confirmed to be RE(Sal-Gly)(NO3)·2H2O, RE(Sal-Gly)(Phen)(NO3)·H2O and RE(Sal-Gly)(Bipy)(NO3)·H2O (RE3+=Eu3+, La3+) as the results of those measurement. The interaction between the rare earth complexes and calf thymus DNA (CT-DNA) was investigated by UV-Vis spectrophotometry and fluorescence spectroscopy. Red shift and hypochromicity of the absorption peak from UV spectra of the complexes were founded in the presence of DNA, and fluorescence quench experiment was used to confirm that the complexes can quench the fluorescence of ethidium bromide-DNA (EB-DNA) system. All these results indicate that intercalation model exists between the complexes and DNA, and good planarity and large surface area of the ligand have a positive effect on the intercalative reaction, so the sequence of binding ability of the complexes to DNA is RE(Sal-Gly)(Phen)(NO3)·H2O>RE(Sal-Gly)(Bipy)(NO3)·H2O>RE(Sal-Gly)(NO3)·2H2O.关键词：rare earth complexes;salicylideneglycine schiff base;CT-DNA;intercalation model92|139|7更新时间：2020-08-12
- 摘要：The interaction machanism of moxifloxacin (MXFX) and ctDNA was investigated by fluorescence spectroscopy. In Tris-HCl buffer solution of pH=7.40, the excitation and emission wavelengths of MXFX are 291 nm and 462 nm, respectively. The fluorescence of MXFX can be quenched by adding ctDNA, which is initiated by conjugation reaction between ctDNA and MXFX. The binding constant of this binary system is 1.28×105 L/mol (25 ℃), and hydrogen bond or Van der Waals force play an important role on the conjugation reaction between ctDNA and MXFX. In addition, three experiments (effect of ionic strength, quenching experiment of I－, and the competition of EB) results indicate that the conjugation mechanism can be considered as MXFX embedding into two adjacent base-pairs of ctDNA.关键词：moxifloxacin;ctDNA;fluorescence spectroscopy;interaction mechanism96|161|3更新时间：2020-08-12
- 摘要：The single layered Ni-Cr metal-dielectric composite spectral selective absorbing films were prepared by bipolar pulsed magnetron sputtering in a gas mixture of oxygen and argon at different oxygen content. The X-ray diffractometer (XRD), Raman spectrometer, ellipsometer, and UV-Visible-NIR spectrometer were used to characterize the phase structure and optical properties of the thin films. The results show that the films composed of Ni, NiO and Cr2O3 exhibit good solar spectrum selective absorption, which have higher absorption in the range of 300~1 200 nm and lower absorption for the wavelength over 1 200 nm.关键词：selective absorption;Ni-Cr metal-dielectric composite films;pulsed magnetron sputtering;phase structure;optical characterization96|122|1更新时间：2020-08-12
- 摘要：The paper proposed a new determination method to meet practical needs of trace detection of dissolved oxygen (DO), which is based on fluorescence quenching and using holy optical fiber (HOF). A DO optical probe was fabricated by modifying the sensitive film doped with fluorophore in the array microholes of HOF, and the sensing character was characterized. The microholes throughout the whole fiber could be used as the substrate of sensing materials and minor reaction pools. Compared with the conventional DO probe, the arrays microholes had huge sensing surfaces and the fluorophore can interact directly with the oxygen molecules, so the sensitivity was improved and also has the potential application in microanalysis detection. From the experimental results, we find the Stern-Volmer plots are linear in the full concentration range of 0~20 mg/L. The ratio of I0/I as a sensitivity of the probe is 3.6, and the probe can make a quick response within 200 ms. The probe has important applications in the dissolved oxygen trace detection.关键词：holy optical fiber;optical sensing;dissolved oxygen;sol-gel137|327|2更新时间：2020-08-12
- 摘要：A novel method for detecting Cu2+ ion was developed based on the fluorescence quenching effect of copper ion on carbon dots (CDs). The fluorescent probe was prepared by grafting reduced carbon dots (rCDs) in calcium alginate to form a calcium alginate film (CA-rCDs). Fluorescence characteristics of the probe and interaction between the probe and metal ions were studied using fluorescence spectrophotometer and UV-Vis spectrophotometer. The results show that the fluorescence intensity of the novel probe is strong and varied with the concentration of Cu2+. Moreover, the quenched fluorescence intensity of probe is linearly proportional to the concentration of Cu2+ in the range from 5×10-6 to 100×10-6 mol·L-1. In addition, it is found that the probe can detect Cu2+ repeatedly by using EDTA. This method is not only suitable for the detection of Cu2+, but also can realize the immobilization of CDs, ensuring the probe to be recycled and reused.关键词：carbon dots;fluorescence characteristics;calcium alginate;fluorescent sensor;copper ion135|87|4更新时间：2020-08-12
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