最新刊期
卷 33 ， 期 4 ， 2012
- 摘要：At present, the commercial tri-color phosphors for PDP application are (Y, Gd)BO3: Eu3+ (red phosphor), Zn2SiO4:Mn2+,BaAl12O19:Mn2+ or (Gd, Y)BO3:Tb3+ (green phosphors) and BaMgAl10O17:Eu2+ (blue phosphor). However, there exists a common problem in the above tri-color phosphors, that is, their luminescence efficiency is low. Moreover, they also present the disadvantages as follows which restrict their luminescence properties: the color purity of (Y, Gd)BO3:Eu3+ is poor; the decay lifetimes of Zn2SiO4:Mn2+ and BaAl12O19:Mn2+ are long; the luminescence intensity of (Gd, Y)BO3:Tb3+ is insufficiency, while BaMgAl10O17:Eu2+ presents poor stability when treated by heating or VUV irradiation. Aiming at these problems, this paper summarizes the recent research progresses on the VUV luminescence mechanism and the improvement of luminescence properties for the tri-color phosphors. Meanwhile, the research progress on the exploring of novel VUV phosphors is also involved.关键词：plasma display;phosphor;luminescence property;synthesis method125|292|4更新时间：2020-08-12
- 摘要：La3PO7:Eu3+ nanocrystals were successfully prepared by combustion method. The structure and morphology of the prepared samples were obtained by X-ray diffraction, scanning of electron microscopy, high resolution transmission electron microscope, respectively. It was found that the average size of the particles was about 80 nm. In La3PO7:Eu3+ samples, the major emission peak is derived from the 5D0→7F2 radiation transition and has a strong red emission and better color purity. The results of emission spectra, laser selective excitation spectra and time-resolved spectra indicate that symmetry of the local environment of Eu3+ is lower and Eu3+ ions occupy at least two types of site in the La3PO7 nanocrystal.关键词：LaP3O7：Eu3+;colorimetric purity;nanocrystal;laser selective excitation94|82|1更新时间：2020-08-12
- 摘要：A series of transparent Ce3+/Sm3+ co-doped glass ceramics were prepared by high temperature melting, and their luminescence properties were studied. In the glass ceramics, Ce3+ ions have shown efficient broadband blue emission due to the 4f-5d transition, and Sm3+ ions have shown bright orange-red luminescence resulting from the 4G5/2→6HJ (J=5/2,7/2,9/2,11/2) transitions. By adjusting the doped concentration of Ce3+ and Sm3+ ions, the chroma of the samples varied gradually. When the mole fraction of CeO2 and Sm2O3 was 1:1, the white light luminescence glass ceramic with the chromaticity coordinate (0.315, 0.296) was prepared. The energy transfer from Ce3+ to Sm3+ ions were investigated by spectra properties and fluorescence decay curves, energy transfer efficiency is about 20% in the SAZKNGC0.6S0.6 glass ceramics. The results indicate that Ce3+/Sm3+ co-doped glass ceramics containing β-Zn2SiO4 are potential matrix materials for white LEDs.关键词：Ce3+/Sm3+ ions;luminescence;energy transfer;glass ceramics;white LED142|67|6更新时间：2020-08-12
- 摘要：Tm3+-doped CdWO4 single crystal with a size of φ25 mm×90 mm was grown by the Bridgman method. The raw mole fraction of Tm2O3 in crystal was 0.5%.The upper part of crystal grown at the final stage appears blood-red color, while the lower at the initial stage brown-blackness. The absorption and IR spectra of various parts of crystal before and after O2-annealing were characterized. The color of the crystal becomes weak after the crystal is treated at O2 atmosphere due to the reducing of oxygen vacant defect. The peaks of 421,684 and 805 nm were observed in the absorption spectra. The peak of 421 nm becomes weak gradually with the increase of annealing tempearture, and almost disappears after 800 ℃. The emission spectra of single crystal were also investigated under the excitation of 808 nm at room temperature. A strong emission band at 1.50 μm and a weak band at 1.80 μm were observed, which corresponding to the 3H4→3F4 and 3F4→3H6 transitions of Tm3+, respectively.关键词：CdWO4 single-crystal;Brigdman method;optical spectra;Tm3+ -doped105|115|1更新时间：2020-08-12
- 摘要：Bi3+ doped,Yb3+ doped and Bi3+,Yb3+codoped Gd2O3 phosphors were prepared by sol-gel method. The preparation conditions of Gd2-x-yO3:Bix3+,Yby3+ phosphors were investigated. The phases of the phosphors were characterized,and the fluorescent properties of Gd2-x-yO3:Bix3+,Yby3+ were studied. Under the excitation of 338 nm, which is the characteristic excitation of Bi3+, NIR emissions of Yb3+ characteristic emission from 900 to 1 100 nm and the characteristic emission of Bi3+ from 500 to 700 nm have been obtained. That suggests a very efficient energy transfer from Bi3+ ions to Yb3+ ions in Gd2O3:Bi3+,Yb3+.The results indicate that the Gd2O3:Bi3+,Yb3+material has potential application in the silicon based solar cells by converting 300~400 nm photon which is almost useless in the silicon solar cell into 400~700 nm and 1 000 nm photons which are absorbed strongly by the Si-solar cell. And the photovoltaic efficiency of the Si-solar cell will be improved.关键词：near-infrared phosphors;sol-gel method;rare-earth doped;energy transfer103|143|0更新时间：2020-08-12
- 摘要：MgO-doped Sr2SiO4:Eu2+ phosphors were synthesized. The introduction of MgO strongly enhances the blue and yellow emission intensity of Sr2SiO4:Eu2+ phosphors. The luminescence properties as a function of MgO and Eu2+ concentrations were studied. White light emission phosphors were obtained when the molar ratio of Mg and Si is around 1.0 under excitation of 400 nm. White light-emitting diode through the integration of InGaN near-UV chip and Sr2SiO4:Eu2+,MgO phosphor was fabricated and exhibited better characteristic parameters than that of the α'-Sr2SiO4:Eu2+ and β-Sr2SiO4:Eu2+ phosphors.关键词：Sr2SiO4：Eu2+;phosphor;luminescence;white light emitting diode114|73|2更新时间：2020-08-12
- 摘要：A new tris-cyclometalated iridium(Ⅲ) complex tris(1-(2, 6-dimethylphenoxy) -4-(4-phenoxyphenyl)phthalazine)iridium(Ⅲ) [Ir(mppppz)3] was synthesized by the direct reaction of a phenylphthalazine derivative with phenolic groups and IrCl3. Under the excitation of 480 nm,complex Ir(mppppz)3 emitted a strong phosphorescence centered at 608 nm in a CH2Cl2 solution and 640 nm in solid. Its lifetime is 268 ns and quantum yield is approximately 0.31 in a CH2Cl2 solution. The HOMO energy level is 5.14 eV and LUMO is 2.91 eV. The organic light-emitting device based on Ir(mppppz)3 (2%) exhibits red electrophosphorescence which peaks at 616 nm. The maximum external quantum efficiency is 1.48%, the luminance is 1 030 cd/m2 and the corresponding efficiency is 0.81 cd/A. The turn-on voltage is 3.9 V with the Commission Internationale de L’Eclairage (CIE) coordinates of (0.64, 0.35).关键词：tris-cyclometalated iridium(Ⅲ) complex;phthalazine;red electroluminescence material84|88|0更新时间：2020-08-12
- 摘要：ndium-gallium-zinc oxide thin film transistor(IGZO-TFT) was fabricated using N2O plasma treated SiNx film as gate insulator and room-temperature deposited IGZO film as active layer. Comparing with the conventional IGZO-TFT, the saturation mobility increased from 4.5 to 8.1 cm2·V-1·s-1, threshold voltage reduced from 11.5 to 3.2 V, threshold swing varied from 1.25 to 0.9 V/dec. The trap states in the N2O plasma treated IGZO-TFT is obviously smaller than that in the conventional IGZO-TFT. Our results indicate that using N2O plasma treated SiNx film as gate insulator is an effective approach for improving IGZO-TFT performance.关键词：thin-film transistor;InGaZnO;plasma treatment;N2O122|57|0更新时间：2020-08-12
- 摘要：We fabricated zinc oxide(ZnO) nanorods using the hydrothermal method and investigated their ethanol gas sensing characteristics under the excitation of light emitting diodes (LEDs) with various wavelengths. The results indicate that the ethanol gas-sensing characteristics of ZnO nanorods strongly depend on the excitation wavelength and intensity of the LEDs. The light-activated gas-sensing mechanism is also discussed.关键词：as sensor;nano zinc oxide;UV light90|135|2更新时间：2020-08-12
- 摘要：The multilayer organic light-emitting diodes (OLEDs) using potassium citrate (C6H5K3O7) as the electron-injection material have been fabricated. The electroluminescence (EL) efficiency of 3.6 cd/A was obtained by inserting 0.5-nm-thick C6H5K3O7 as electron injecting layer, which is higher than that of 2.5 cd/A in reference device with 0.5-nm-thick LiF. The turn-on voltage was decreased 0.5 V compared with the reference device with 0.5-nm-thick LiF. The results demonstrated that C6H5K3O7 is a promising electron injection material.关键词：organic light-emitting diodes;potassium citrate;electron injection layer88|103|0更新时间：2020-08-12
- 摘要：Considering the good conductivity and anti-electromigration and low price, Cu films were prepared as electrodes of ZnO-based devices via pulsed laser deposition method on Si(111) substrates. The XRD and SEM images of ZnO/Cu films were examined and the current-voltage characteristics were measured. The results exhibit that ZnO films are highly c-axis oriented, and Cu films are highly (111) oriented. Ohmic contact can be obtained when the ZnO:Cu layer was involved between the ZnO film and the Cu film, and the Ohmic contact properties can be improved after annealing. Study on how to improve the properties of Ohmic contact of the ZnO/Cu films is still continued. The results indicate that Cu may be used as Ohmic contact electrodes for ZnO-based devices.关键词：ZnO thin films;Cu electrode;MSM structure;ohmic contact88|137|0更新时间：2020-08-12
- 摘要：H:ZCO thin films were prepared with different qv(H2):qv(Ar+H2) by using submolecule doping technique, where the magnetic sputtering of Co and ZnO were alternatively performed onto silicon substrates. The effect of qv(H2):qv(Ar+H2) on the structural and magnetic properties in films was investigated. All the prepared thin films have a c-axis preferential orientation, and the intensity of (002) diffraction peak decreases with the increase of qv(H2):qv(Ar+H2) in films because the doping hydrogen can passivate the dangling bonds at the surfaces and grain boundaries. Magnetic measurement shows that the ferromagnetism is enhanced with the qv(H2):qv(Ar+H2) increasing. XPS results exhibit that the relative content of Co metal clusters gradually increases, and the relative content of oxidized Co ions gradually decreases with the increase of H2 ratio. According to the above results, it is suggested that the ferromagnetism in H:ZCO thin film originates from Co metal clusters, and more oxidized Co ions is reduced to Co metal clusters with H2 doping, therefore the ferromagnetism is enhanced.关键词：magnetron sputtering method;ZnCoO diluted magnetic semiconductor;H doping;Co metal clusters87|184|0更新时间：2020-08-12
- 摘要：A double layer NPB/Alq3 heterojunction organic light emitting device using Ag/4-FTP(SAM)/m-MTDATA as combined hole-injecting layer was fabricated. The device performance was studied and compared with the control device. The effect of the Ag layer thickness on the device performance is also investigated. The variation of the spectral narrowing and intensity enhancement can be explained with microcavity effects. The results revealed that indium tin oxide (ITO) anode modified with Ag(5 nm)/ 4-FTP(SAM) demonstrated good transparency, enhanced hole injection ability and smooth interface morphology, which result in an improved device performance. The highest luminance of 34 680 cd/m2 at 12 V and a luminous efficiency of 6.9 cd/A were achieved for the device with the structure of ITO/Ag/4-FTP(SAM)/m-MTDATA/NPB/Alq3/LiF/Al. However, the control device showed 25 300 cd/m2 at the same bias.关键词：self-assembled monolayer;anode;organic light-emitting devices;microcavity effects;current efficiency95|107|2更新时间：2020-08-12
- 摘要：A write-once-read-many-times (WORM) bistable device was prepared, in which ZnS quantum dots doped poly-4-vinyl-phenol (PVP) layer was sandwiched between ITO anode and Al cathode. Current-voltage (I-V) curves showed a switching characteristic with a large ON/OFF ratio of 104. The electrical bistability properties and charge-transport mechanisms were discussed in detail based on I-V characteristics. The conduction mechanisms in both ON- and OFF-states were discussed in terms of different theoretical models. The data-retention characteristics of the current-time (I-t) curve exhibited permanent retention ability at ambient conditions.关键词：OBD;ZnS quantum dots;charge-transport mechanism;poly-4-vinyl-phenol84|103|1更新时间：2020-08-12
- 摘要：We examine the absorption and dispersion properties of a weak probe field in a three-level lambda system closed by a microwave field. We find that, due to quantum interference in this closed-loop atomic system, the absorption and dispersion properties of a weak probe field depend on the relative phase of the applied fields. A large inversionless gain and a large index of refraction with zero absorption can be obtained by tuning the relative phase into proper values. In the case of three-photon off-resonance, the probe gain (absorption) exhibits periodically oscillatory behavior versus time.关键词：quantum interference;phase-dependent effect;inversionless gain;large index of refraction with zero absorption118|89|0更新时间：2020-08-12
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Properties Improvement of Polymer White Organic Light Emitting Devices by Phosphorescence Sensitizer
摘要：Based on a new polymer of PF-DTFO, the novel polymer white light-emitting diode (PWOLED) was introduced with the structure of ITO/PEDOT:PSS/PF-DTFO/LiF/Al. Because of its excess blue emission, the modified PWOLEDs were developed by doping phosphorescence dye of FIrpic in emission layer. In the PWOLEDs, triplet excitons’ energy can transfer from FIrpic to long-wave emissive groups of PF-DTFO, which lead to an increased long-wave emission intensity. By using this phosphorescence sensitizer layer, both singlet and triplet excitons can be effectively employed, and the performance of the PWOLED was improved. The PWOLED shows a little change of CIE coordinate,which ranges from (0.33, 0.38) to (0.32, 0.38) as the driving voltage increased from 8 V to 16 V. Meanwhile, the device shows about 38% enhanced efficiency compared to that of unoptimized PWOLED.关键词：polymer;OLED;phosphorescence sensitizer99|128|1更新时间：2020-08-12 - 摘要：This paper demonstrates a novel carrier-injection-type silicon based light emitting device (LED) with three terminals and high light emission intensity. The device was designed and fabricated in the commercial standard 0.5 μm CMOS process offered by Central Semiconductor Manufacturing Corporation (CSMC) without any modification. Two shallow diagonal n+p junctions were embedded on the p type substrate. One junction biased in forward mode emits infrared light, and the other is also forward biased to inject carriers into the light emitting region. Experiment results show that, at 10 mA biased current and 3 V modulation voltage, 1 nW optical power can be obtained and it’s approximately two orders of magnitude higher than the single junction. Due to the low operating voltage, the device can be monolithic integrated with the current mainstream silicon CMOS technology and shows a great potential in optoelectronic integration field.关键词：Si-LED;standard CMOS;light emitting device;carrier injection;OEIC96|102|2更新时间：2020-08-12
- 摘要：The characteristics of a ZnO/ZnMgO heterostructure field-effect transistor (HFET) were reported in this paper. The HFET was grown on α-plane sapphire substrate by metal-organic vapor phase epitaxy (MOVPE) technology, and was fabricated by a conventional photolithography technique combined with wet etching. The experiment results indicated that the HFET was an n-channel depletion type with a transconductance of 180 μS·mm-1 and mobility of 182 cm2·V-1·s-1 at room temperature. The property was limited by leakage current through the SiO2 gate insulator. At low temperature, the performance was improved due to the reduced leakage current.关键词：ZnO/ZnMgO;heterostructure field-effect transistor(HFET);mobility86|208|0更新时间：2020-08-12
- 摘要：In the ammonia-ammonium chloride buffer solution of pH=7.4, europiumion(Eu3+) and norfloxacin(NFLX) react and combine as steady complex under room temperature. The complex shows its sensitized fluorescence of rare earth. The maximum excitation wavelength and maximum emission wavelength are 340 nm and 612 nm, respectively. The fluorescence intensity has a further increase in sodium dodecyl sulfate(SDS). When neomycin sulfate solution is added, the fluorescence intensity of the system of Eu3+-NFLX-SDS diminishes, while the locations of the excitation and emission wavelengths stay the same. According to this result, a new way to determine the concentration of neomycin sulfate is established. The concentration range that neomycin sulfate can detect is 0.909~22.7 mg/L. The detection limit is up to 0.4 mg/L. This measurement has been applied to determine neomycin sulfate in tablet and drops. The relative standard deviation is 1.4%~3.5% for 6 parallel determination of neomycin sulfate samples and the recovery is 90.5%~102.3%.关键词：neomycin sulfate;europiumion;norfloxacin;sodium dodecyl sulfate;fluorescence quenching112|187|4更新时间：2020-08-12
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