最新刊期
卷 33 ， 期 12 ， 2012
- 摘要：A new neutral dinuclear copper(Ⅰ) complex bearing N-ligands 2,9-di-n-butyl-1,10-phenanthroline (dnbp), [CuI(dnbp)]2, was synthesized by the reaction of CuI and dnbp in tetrahydrofuran solution. The complex was characterized by single crystal X-ray diffraction, 1H NMR, UV-Vis spectra, and photoluminescence spectra. The results show that the complex consists of a distorted tetrahedral Cu2I2 core, in which two copper(Ⅰ) ions are linked by two iodo-bridges, and two dnbps chelated with copper(Ⅰ) ions, respectively. The complex shows small angle of I—Cu—I (106.08°), and long Cu…Cu distance (0.314 9 nm) which suggests a negligible interaction between two copper ions. These features can be attributed to the bulk steric hindrance of dnbp ligands. The complex belongs to trigonal system with space group of R-3 and cell dimensions a= 4.404 14(11) nm, b= 4.404 14(11) nm, c=1.085 92(4) nm, γ= 120°, V=18.241 1(9) nm3. The complex has a low-energy absorption band ranging from 350 nm to 500 nm in dichloromethane solution, which can be assigned to the metal-to-ligand charge transfer (MLCT) transitions. At room temperature, the complex in the solid state exhibits red photoluminescence with a broad emission band from 550 nm to 800 nm and the maximum peak at 653 nm under excitation at 365 nm. The emission lifetime of the complex is 3.1 μs, and photoluminescence quantum yield is 0.013. The luminescence mechanism of the complex belongs to the phosphorescent emission at the exited state, which is formed by electron charge transition from cuprous ion and halogen to ligand dnbps. At 10 K, the maximum emission peak shifts to 645 nm with narrow spectral band width.关键词：copper(Ⅰ) complex;2;9-di-n-butyl-1;10-phenanthroline;crystal structure;phosphorescence98|108|0更新时间：2020-08-12
- 摘要：ZnMoO4 microcrystals with diffrent morphologies and structures have been successfully prepared via hydrothermal method using Zn(Ac)2 and (NH4)6Mo7O24?4H2O. In the synthesis process, cetyltrimethyla-mmonium bromide (CTAB), sodium dodecyl sulfate(SDS) , polyvinyl pyrrolidone-K30 (PVP-K30) and ethylene diamine tetraacetic acid(EDTA) were added, respectively. XRD, SEM, photoluminescence (PL) were used to characterize the as-obtained ZnMoO4 microcrystals. The results suggest that the morphologies and structures of ZnMoO4 microcrystal can be controlled by changing the type and dosage of the adjuvant or varying the reaction time, the luminous intensity of the samples are different and the luminous center are all around 565 nm.关键词：ZnMoO4 microcrystal;hydrothermal method;photoluminescence94|190|1更新时间：2020-08-12
- 摘要：A new copper(I) complex of [(POP)CuI]2 [POP∶bis-[2-(diphenyl phosphino)phenyl]ether] with blue emission was designed and synthesized. The molecular structure and photophysical properties of [(POP)CuI]2 were investigated by FT-IR spectra, X-ray single crystal diffraction, UV-Vis absorption, emission spectra and cyclic voltammetry. The results indicate that the UV-Vis absorption peaks of [(POP)CuI]2 are located at 227, 268 and 291 nm. The blue light can be observed with a peak at 475 nm in the solid state. The HOMO, LUMO energy levels and optical gap are -6.40, -3.47 and 2.93 eV, respectively. The devices of ITO/NPB(30 nm)/CBP∶[(POP)CuI]2(30 nm, 8%)/BAlq(10 nm)/Alq3(30 nm)/LiF(1 nm) /Al (200 nm) were fabricated by doping [(POP)CuI]2 into CBP as emitting layer with emission peak at 476 nm and maximum luminance, current efficiency of 9 539 cd/m2, 1.9 cd/A.关键词：copper(Ⅰ) complex;bis-[2-(diphenylphosphino)phenyl] ether;blue phosphorescence93|166|0更新时间：2020-08-12
- 摘要：ErF3 doped indium oxide (IEFO) transparent conductive film was fabricated by electron beam evaporation. The optical, electrical characteristics and crystal structure of the IEFO film were studied. The IEFO film is polycrystalline structure, the introduction of Er changes the preferred orientation of lattice and makes the growth tendency of the (211), (222), (444) similar. The IEFO film shows a resistivity of 1.265×10-3 Ω·cm, a carrier mobility of 45.76 cm2·V-1·s-1, a carrier concentration of 1.197×1020 cm-3, and the optical transmittance of 81% at the range of 380~780 nm. The surface morphology of IEFO film in different thickness was tested by atomic force microscope and the growth process was discussed.关键词：transparent conductive film;morphology;In2O389|123|1更新时间：2020-08-12
- 摘要：ZnO films with and without nanorods on the surfaces were prepared by a chemical vapor deposition technique. Au nanoparticles were deposited on the surfaces of ZnO films with and without nanorods by the direct circuit sputtering method. Photoluminescence of the ZnO film with nanorods is tuned by the surface modification of the surface plasmons. Comparing with the ZnO film without nanorods, the near band gap emission from the ZnO film with nanorods is greatly enhanced and visible emission from defects is significantly suppressed. This phenomenon is attributed to the efficient coupling of surface plasmon resonance of Au nanoparticle with ZnO nanorods and the transfer of high energy electrons in Au nanoparticles to conduction band of ZnO.关键词：ZnO;photoluminescence;surface plasmons101|124|0更新时间：2020-08-12
- 摘要：It is critical to achieve high quality and stability SiO2 barrier in making high-power semiconductor lasers, SiO2 barrier layer was grown on GaAs substrates using high efficiency LaB6 ion assisted in low current. The stress effects were tested and analyzed after annealing. The stress conditions of different thickness and different growth rates were experimentally investigated and the deposition process was analyzed. The results show that the stress of SiO2 film under the conditions of ion-assisted deposition is far less than the conventional deposition conditions. The stress of SiO2 film under the conditions of ion-assisted deposition changes smaller after annealing.关键词：ion-assisted deposition;SiO2 film;stress;annealing128|189|4更新时间：2020-08-12
- 摘要：Mercaptopropionic acid (MPA) modified high quality CdTe quantum dots (QDs) were prepared by hydrothermal synthesis method in a high temperature. The influences of different reaction time and different pH value of the reactive precursor solution on the optical properties of CdTe QDs were studied. The results indicate that the fluorescence emission wavelength of the as-prepared CdTe QDs can be adjusted continuously at a range of 510~661 nm, and the optical properties of CdTe QDs strongly depend on the pH value of the reactive precursor solution(the optimum pH value is 9). The samples were characterized by transmission electron microscopy and X-ray diffraction. The results show that the shape of the as-prepared CdTe QDs is closed to sphere, and the particle size distribution is uniform. Comparing with the reflux method for preparing water-soluble QDs, the hydrothermal synthesis method at a high temperature is relatively simple, and the reaction time is shorter, the growth of CdTe QDs is faster, the particle size can be grown to 3.5 nm within 100 min. The as-prepared CdTe QDs possess higher fluorescence intensity, good stability and higher fluorescence quantum yield (up to 44.6%).关键词：CdTe;mercaptopropionic acid;hydrothermal;fluorescence92|117|3更新时间：2020-08-12
- 摘要：The afterglow materials CaAl2O4∶Eu2+, Gd3+ were synthesized by high-temperature solid- phase method. The structure and luminescent properties of the samples were characterized by X-ray diffraction (XRD) and fluorescence spectra at room temperature. The effects of luminescent properties for 3.5% Eu2+(mole fraction) and 0.5% boric acid (mass fraction) doped CaAl2O4∶Eu2+, Gd3+ with different mole fraction of Gd3+ (2%, 3%, 4%, 5%) were investigated in detail. The results showed that CaAl2O4∶Eu2+,Gd3+ were successfully synthesized and the structure was not changed even introducing Eu2+ and Gd3+ into the samples. The photoluminescence excitation and emission spectra were both broad bands. The dominanted emission band centre located at about 444 nm which was the blue emission of the transition of 4f65d→4f7. The luminescence intensity of blue phosphors CaAl2O4∶3.5%Eu2+,3%Gd3+ is the best among all samples.关键词：high-temperature solid-phase method;luminescent materials;CaAl2O4∶Eu2+;Gd3+107|140|2更新时间：2020-08-12
- 摘要：BaGd2ZnO5 phosphors with different doping concentrations of Yb3+, Er3+ were prepared by using the sol-gel method. Up-conversion fluorescence powers and efficiencies were measured under different excitation density. The obtained data show that each sample has a maximum value in emission power. Among those sample, the sample of doping Yb3+ (4%), Er3+ (1%) has the highest power of 20 mW. Each sample had a maximum value of up-conversion absolute fluorescence efficiency. This value shifts to the lower exciting density with the increasing content of Yb3+ and Er3+. The highest efficiency is 3.2% for Yb3+ (9%) and Er3+ (3%) sample, and the highest fluorescence efficiency is 6.9%。关键词：BaGd2ZnO5;up-conversion;oxidate;Yb3+;Er3+100|88|4更新时间：2020-08-12
- 摘要：The improvement of the performance for CdSe quantum dot light emitting diodes (QD-LEDs) was studied by using the inverted device structure and localized surface plasmon resonant (LSPR) coupling of Au nanoparticles with the QDs. We fabricated inverted QD-LEDs with TiO2 as the electron injection/transport layer. The current density-voltage characteristics of electron-only device were studied. The electron-injection current from the top Al electrode with the forward-bias voltage (Al was used as the cathode) was symmetrical with that of the bottom ITO electrode with reverse-bias voltage (ITO was used as the cathode), indicating the electron injection from ITO to TiO2 is facilitated like the case from Al cathode. It was noticed that the efficiency of QD-LEDs with Au nanoparticles was enhanced while the drop rate of the efficiency was clearly reduced with increasing the current density. A significant enhancement of 42% for current efficiency of the LEDs was achieved under high current density of 200 mA/cm2.关键词：quantum dot;electroluminescence;inverted quantum dot LED;metal nanoparticle99|123|2更新时间：2020-08-12
- 摘要：The effects of band structure and optical properties of TiO2 doped Ag+, Fe3+, Pt4+, La3+ ions were analyzed by using Materials Studio. The molecular simulation shows that metallic ion doping can make the forbidden bandwidth of TiO2 narrow, the absorption wavelength of TiO2 red-shift, and the optical absorption coefficient increase in the same light condition. The changes affect the photocatalytic ability of TiO2. Under 254 nm UV light, TiO2 shows the best photocatalytic ability when the forbidden bandwidth is 1.09 eV, and the higher optical absorption coefficient.关键词：TiO2;molecular simulation;forbidden bandwidth;optical absorption coefficient;metallic ion doping121|90|8更新时间：2020-08-12
- 摘要：Two 915 nm diode laser short bars were used as sub-module to manufacture high brightness fiber coupled module with continuous wave(CW) output power. Firstly, beam shaping technology was employed for each sub-module to enhance its beam quality. Secondly, the two beams were stacked in direction of lower beam parameter product by means of spatial multiplexing technology. Finally, the laser was focusing into a multimode fiber with 200 μm core diameter and NA=0.22 by optimized lens by focusing lens. Experiment results show that the beam waist diameter at focal plane is 105.4 μm when driving current is 52.5 A, the optical power output from fiber can reach to 72.6 W with a brightness of 6.08 MW/(cm2·sr), and the wallplug efficiency is 42.2% when driving current is 52.5 A. The character of heat dissipation was studied by means of measuring spectrum with different current, and the results prove that the module has favorable heat dissipation.关键词：high brightness;diode laser short bars;fiber coupling;aspherical focusing lens;high efficiency82|252|5更新时间：2020-08-12
- 摘要：To enlarge the energy of the pico-second laser pulse and to gain the higher laser amplifying efficiency and the higher ratio of the signal to noise in the pulse amplification, we should oscillate the CW mode-locked laser in the lower repetition frequency while the laser outputs the high average power. By designing and optimizing the five-mirror-folded laser resonator, we controlled the light loss increasing with the resonator length and the unstable running of the long cavity in CW laser mode-locked. We observed that the relevant or corresponding path of the resonator increase with the decrease of another arm path because of the energy requirements for the saturation working and stability state of the SESAM in the laser. We realized an SESAM CW mode-locked laser with the pulse energy of 10.7 nJ, the output power of 1.2 W.关键词：SESAM;CW mode-locked;end pumping;low pulse frequency103|185|2更新时间：2020-08-12
- 摘要：The optical transmission of one dimensional photonic crystal (PC) containing TiO2 and SiO2 material with triply-periodical heterostructures was investigated by transfer matrix method. The results show that there are seven photonic band gap (PBG) in the range of 200~2 000 nm in PC, and the band gap width increases with the wavelength. The authors put emphasis on the relationship between the optical transmissionof this kind PCs and incident angle, layers of dielectric, as well as dielectric layer thickness. It is found that the width and position of band gap are sensitive to incident angle and dielectric layer thickness, but not periodic numbers.关键词：triply periodic heterostructures;photonic crystal;transmission matrix;PBG;filter84|182|0更新时间：2020-08-12
- 摘要：Light-emitting diodes containing multilayer laminated structure are fabricated by spin-coating CdSe/ZnS quantum dots (QD) films as emitting layer. The dependences of process conditions and parameters on the electroluminescence and the QD film morphology are researched by using atomic force microscopy. The results show that with the increased thickness of QD, the multi-layer nano-particle films are formed, which leads to the QD nano-particles agglomerate and the brightness of device decrease. In addition, the annealing temperature of the QD layer has an important impact on the device brightness. When annealing temperature is low, the device shows poor performance due to the solvent volatized incompletely. When annealing temperature is above 150 ℃, the heat generated from annealing will cause the agglomeration of the QD nano-particles and then the performances of devices decline.关键词：quantum dot;light-emitting diode;agglomeration112|238|1更新时间：2020-08-12
- 摘要：The black silicon has been successfully produced by Au particle-assisted chemical etching. The microstructure, reflectance, surface morphology and photoluminescence properties of black silicon have been investigated by atomic force microscope, spectrophotometer, infrared spectrometer and photoluminescence spectrometer, respectively. The results show that the obtained black silicon exhibits a mountain-like structure with the average reflectance of 3.31%. The mechanism of black silicon produced by Au particle-assisted chemical etching is the combination of etching effect and passivation effect. The photoluminescence spectrum can be separated into three peaks which results from quantum confinement effect, siloxene, impurity and defect, respectively.关键词：black silicon;microstructure;reflectivity;infrared spectroscopy;photoluminescence spectroscopy89|404|2更新时间：2020-08-12
- 摘要：A novel method that without aluminum substrate high-power LED encapsulation is proposed. The thermal properties of traditional structure and this new structure is simulated by using finite element analysis software. The simulation results show that the maximum temperatures appear in the LED chips. Comparing with the traditional structure, the maximum temperatures of the new structure respectively lower 6.436, 9.468 and 19.309 ℃ when the input power is 1×1 W, 3×1 W and 1×3 W. Even if the thermal conductivity of substrate reaches as high as 200 W/(m·K), the heat dissipation effect is still better than the structure with aluminum substrate. The heat dissipation effect of the new structure is obviously superior to that of aluminum substrate structure. With the increase of input power, the advantage of the new structure is more remarkable. It provides a new way to solve the heat dissipation problem of high power LED.关键词：thermal resistance;high-power LED;aluminum substrate;ANSYS finite element analysis;thermal analysis100|177|6更新时间：2020-08-12
- 摘要：The optical properties of the InGaN/AlGaN light-emitting diodes (LEDs) with varied quantum well(QW) numbers are studied numerically. The simulated results show that the single quantum-well (SQW) structure has the best optical performance with small current less than 100 mA. However, the 9-QWs structure obtains higher output power and IQE than other structures when the current is larger than 700 mA, and the efficiency droop is dropped markedly from 14.10% to 5.15% at 700 mA comparing with that of the SQW structure. Therefore, 9-QWs is the optimized structure for high-power LEDs. It can be explained as follows: (1) The 9-QWs structure acquires higher capacity of carrier confinement due to the smaller band bending effect and the effective hole potential barrier heights formed by the electron block layer (EBL). (2) When the QW number is less than 9, the lower capacity of carrier confinement and lower radiative recombination rate in the active region reduce the performance of the device, though the turn-on voltage is lower. (3) When the QW number is more than 9, the structure shows higher peak internal quantum efficiency (IQE) and less serious efficiency droop compared with 9-QW structure. However, the smaller IQE and larger band bending effect make it worse for a high power structure.关键词：number of quantum well;numerical simulate;InGaN/AlGaN LED;high power112|286|0更新时间：2020-08-12
- 摘要：The benzylporphyrin (PP)-functionalized polyglyceryl methacrylate (PGMA) and the hydroxylbenzylporphyrin (HPP)-functionalized PGMA, i.e. PP-PGMA and HPP-PGMA, were coordinated with Zn2+ ion respectively, resulting in the Zn porphyrin-functionalized PGMA, i.e. ZnPP-PGMA and ZnHPP-PGMA. The chemical structures of ZnPP-PGMA and ZnHPP-PGMA were characterized by nuclear magnetic resonance (1H-NMR) spectroscopy. The spectroscopic properties of ZnPP-PGMA and ZnHPP-PGMA were studied by means of UV-Vis spectroscopy and fluorescence spectroscopy. The axial coordination reaction between two kinds of Zn porphyrin-functionalized PGMA and terbuthylazines was studied by using the fluorescence spectrum titration method. The affective factors for fluorescence character of axial coordination reaction were investigated. The results show that both ZnPP-PGMA and ZnHPP-PGMA have possessed strong spectral characteristics. Comparing with PP-PGMA and HPP-PGMA, the Soret absorption bands of ZnPP-PGMA and ZnHPP-PGMA exhibited obvious red shift, and the blue shift occurred for Q emission bands of them. In addition, both the Soret and Q absorption bands of ZnPP-PGMA exhibited red shift in the electronic absorption spectra. The fluorescence quenching occurred in the product of terbuthylazine. The fluorescence quenching for ZnHPP-PGMA was a little less than ZnPP-PGMA. It is because the hydrogen bonding between ZnHPP-PGMA and terbuthylazine led to the weaker axial coordination. Moreover, the fluorescence quenching of ZnHPP-PGMA was strengthed with the increasing concentration of terbuthylazine.关键词：Zn porphyrin;polyglyceryl methacrylate;terbuthylazine;axial coordination reaction;fluorescence quenching94|146|2更新时间：2020-08-12
- 摘要：To apply the chemiluminescence immunoassay method in clinical applications, some key technologies were investigated based on deeply analyzing the chemiluminescence immunoassay process. Firstly, three key steps about the immunoassay were indicated: filling-up, washing and measuring. Accordingly, three key technologies were summarized: accurate filling-up of microcontent liquid, quick and effective separation of immune complex, and accurate measurement of weak optical signal. In the aspect of filling-up, based on the analysis and simulation of milliliter level liquid filling-up process, the principle for optimizing relative sampling parameter was obtained. In the aspect of washing, the principle for designing the magnetic field was then obtained based on the analysis of separating immune complex process. In the aspect of measuring, the principles for designing measuring room and processing optical signal were given. After investigating the above-mentioned key technologies, chemiluminescence immunoassay analyzer Autolumis 3000 has been developed and applied in hospital. The results show that the coefficient of variance (CV) is 5% and the maximum speed is 180 time/h. This analyzer can achieve similar performance comparing with the current high-end equipment in abroad, which validates our investigation of the key technologies.关键词：chemiluminescence;immunoassay;medical instrument106|327|3更新时间：2020-08-12
- 摘要：The optimum molecular geometry of phenanthrene (PHE) was calculated by the B3LYP method of density functional theory (DFT) using 6-311++G(d,p) basis sets, and data source of vibration frequency, polarizability, and thermo-dynamical parameters were set up. By contrast with the experimental spectra, the vibrational assignment of PHE was discussed. In addition, part of significant parameters such as HOMO-LUMO energy gap, molecular electrostatic potentials and atomic charge were calculated based on the frontier molecular orbital, molecular electrostatic potentials and Mulliken population analyses. This study provides a theoretical support for the spectral detection technology, especially for the analysis of the electronic structure and spectra of PAHs.关键词：density functional theory (DFT);phenanthrene;vibrational spectra;frontier molecular orbital;molecular electrostatic potentials106|237|3更新时间：2020-08-12
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