最新刊期
卷 19 ， 期 3 ， 1998
- 摘要：By introducing terms describing the random frequency modulation into optical Bloch equation, we have discussed spectral diffusion in such systems after a narrow band excitation. Especially, 1) if ω jumps to any other ω′ in the ensemble with equal probability, the time dependent lineshape would be a superposition of an exponentially decayed localized line and an exponentially grown background; 2) if the probability that ω jumps to ω′ depends on |ω′-ω|, the delocalized peak would be broadened with time. We have also discussed spectral diffusion in the system with frequency modulated by numbers of independent random telegraph processes as an example.关键词：spectral diffusion;random frequency modulation;optical Bloch equation106|76|0更新时间：2020-08-11
- 摘要：GaAs/AlGaAs quantum dots were made by Electron Beam Lithography (EBL) and Reactive Ion Etching(RIE) on GaAs/AlGaAs quantum well wafers. Their photoluminescence shows blue-shift, the amount of blue-shift increases with the decrease of quantum dot size.关键词：GaAs/AlGaAs;quantum dot;luminescence115|89|1更新时间：2020-08-11
- 摘要：The transitions from two groups superlattices was observed, by measuring its electro-modulated reflectance spectra, the transition energies obtained by the curve fitting are coincide with the results obtained by calculating from envelope functuin approximate including strain.关键词：ZnCdSe-ZnSe compound superlattices;electro-modulated reflectance spectra126|83|1更新时间：2020-08-11
- 摘要：Nonocrystalline Si (nc-Si) thin films were prepared by crystallization of the hydrogenaed amorphous Si (a-Si) films using the three-step Rapid Thermat Processing (RTP), i. e. evolution of the hydrogen, nucleation at high temperature and growth at low temperture. Green/Blue light emisson from the nc-Si thin films were observed under excitaion of Ar+ laser (457.9nm)at room temperature.关键词：green/blue photoluminescence;nc-Si thin film;RTP99|90|0更新时间：2020-08-11
- 摘要：Photoluminescence spectra of nanocrystallites X1-Y2SiO5:Eu were recorded at 15K using site selective excitation by a dye laser. The results show that there is a pronounced energy transfer from site 2→1 and the transfer rates increases with increasing of Eu3+ concentration. The fluorescent lifetimes of the two sites were also measured as a function of concentration. As expected, we found that the lifetimes of site 2 decreases with increasing concentration. Decay curve measurement of site 1 under exciting site 2 revealed the transfer process directly. The mechanism of the energy transfer is discussed.97|65|2更新时间：2020-08-11
- 摘要：The changes of excitation spectrum, emission spectrum, luminescence efficiency and the time resolved spectra of Mn2+ in nanometer-size ZnS clusters sticked to a chitosan medium were investigated. The causes of the changes of the luminescence properties have been discussed. Experiment shows that the decay time of Mn2+ in nanocrystals is shorter 2 orders than that of bulk ZnS:Mn. The oscillator strength of Mn ion radiative transition was disscussed according to these results of measurements.关键词：Mn doped ZnS nanocluster;quantum size effect;time resolved spectrum;oscillator strength99|97|0更新时间：2020-08-11
- 摘要：In this paper, the crystal structures and phase transition on Gd2O3:Eu nanophosphors have investigated for the first time. The crystal structures of Gd2O3:Eu nanophosphors by X-ray diffraction show a body-cubic and monoclinic. As observed in XRD analysis, the transition temperature from cubic to monoclinic phase in Gd2O3:Eu nanocrystal increased to 1300～1350℃ from 1250℃ for bulk material. The result is also confirmed by the changing of the Eu3+ emission spectra of Gd2O3:Eu nanophosphors.关键词：Gd2O3：Eu nanophosphor;nanocrystal;Gd2O3;phase transition;crystal structure99|99|10更新时间：2020-08-11
- 摘要：This paper proposed a new method to obtain EL from Si nanocrystallotes. Blue ACTFEL was observed from Si-rich SiO2 films prepared by if reactive magnetron sputtering technique. The blue bands were proved to relate to the Si nanocrystalline embedded in Si-rich SiO2 films by post annealing as well as Raman spectral analysis. The EL properties were consistent with the quantum size effect.关键词：Si quantum dots;Si-rich silicon dioxide;electroluminescence112|256|2更新时间：2020-08-11
- 摘要：Using AIN ceramic as substrate, we grow a series of diamond films under different CH4 to H2 volume ratio. Comparing their temperature-dependent PL from room temperature down to 100K and correlating the PL spectra with their Raman shift, we can get some of the structure and growth information. The intensity of diamond’s photoluminescence increases with the ratio of CH4 to H2 at first, and reaches its maximum when the CH4 ratio is 3%. Afert that, PL decrease when the CH4 growth rate continue to increase. We think the PL intensity might be caused by the recombination of defect states(such as stack fault). When the CH4 concentration increase, the graphite components also increase, which enhance the possibility of non-radiative transition.关键词：diamond films;HFVCD;photoluminescence101|90|0更新时间：2020-08-11
- 摘要：We have studied the emission and excitation spectra of PbWO4 and PbWO4:Dy3+ single crystals. The results showed that Dy3+ ion can enter into PbWO4 crystals which have complicated structure, luminescent centers in PbWO4 crystals can transfer the energy to Dy3+ ion, which leads to increase the luminescence intensity of Dy3+ ion. So PbWO4:Dy3+ single crystal is a potential, new rare earth scintillator with high density.关键词：PbWO4：Dy3+;rare earth scintillator;excitation;emisstion spectrum;energy transfer119|80|1更新时间：2020-08-11
- 摘要：The dependence of ultraviolet (～390nm) and green (～520nm) luminescent peaks of ZnO film prepared by direct curren sputtering under cathode-ray excitation on excitation electron beam current has been investigated. With the increase of the intensity of excitation electron beam current, green peak relatively decreases and ultraviolet peak relatively increases, so that the luminescent color or ZnO film changes from green to blue-violet. The green peak intensity increases sublinearly with the increase of the intensity of electron beam current and saturates under relatively low intensity of electron beam current. But the 390nm ultraviolet peak intensity increases superlinearly with the increase of the intensity of electron beam current. This is a sign of emitting ultraviolet laser from ZnO film under cathode-ray excitation under room temperature. This kind of ultraviolet laser from ZnO film may come from a super-radiation lasing luminescence under high density excitation.关键词：ZnO;cathodoluminescence;ultraviolet laser;super-radiation lasing luminescence116|86|11更新时间：2020-08-11
- 摘要：We study the luminescence brightness and spectrum of YAGG:Tb phosphors with different kind of rare earth. We found that with Gd3+ as co-dopant, the brightness will improved.关键词：rare earth;YAGG：Tb;cathodeluminescence phosphor122|105|1更新时间：2020-08-11
- 摘要：The Eu2+ halophosphates are studied in the time-resolved station(U10B) of the National Synchrotron Radiation Lab. The (Ca,Sr,Ba)5(PO4)3Cl:Eu2+ and (Ca,Sr,Ba)5(PO4)3Cl:Eu2+ samples are studied on the irradiation properties and the reflection spectra. Excited by the 185nm, the decrease of the emission intensity of (Ca,Sr,Ba)5(PO4)3Cl:Eu2+ is not observed in 60 minutes; on the other hand, the emission intensity of (Ca,Sr,Ba)5(PO4)3Cl:Eu2+ is observed to have a stronger decrease in 15 minutes. According to the reflection spectra of the two samples(from 100nm to 400nm), there is a large difference on 185nm between two samples. At the same time, in the absorption spectra got by the K-K relation, the absorption efficiency of two samples are different. We think:when the Ba2+ is added into the sample, the crystal symmetry is changed, then the (O)- energy level changed. The 185nm excitation efficiency of the electron from (O)- center decreased. So it can resist the 185nm radiation.关键词：halophosphate;ultraviolate-radiation;Eu2+;color center93|73|2更新时间：2020-08-11
- 摘要：The powder emitting phosphor CaS:Bi was prepared, whose crystallinity was analysed by X-ray diffraction. The excitation, emission and DCEL spectra of CaS:Bi were measured. The blue emitting peak is at 450nm.关键词：CaS：Bi;phosphor101|116|0更新时间：2020-08-11
- 摘要：A part of Ba ions is replaced by Ca ions in the BaMgAl10O17:Eu blue phosphor and the effect of this replacement is studied. After 4～12mol% of the BaO is replaced by CaO the emission above 500nm reduced as well as the chromaticty coordinate Y and the intensity of emission peak raised, so the performance of phosphor is improved.关键词：blue-emission phosphor;aluminate;Eu2+136|99|2更新时间：2020-08-11
- 摘要：To prepare the sample for concentration 0.05wt.% of BMPPV in PVK was used, a solution of 2g PPV and 1mg BMPPV in 2ml of trichloromethane, Polymers was spincoated on DBR with 99.5% reflectivity, 300nm of Ag film was formed by the thermal evaporation, surface emitting microcavity was formed.The samples were optically pumped with 10ns pulses at a 20Hz repetition rate by a Nitrogen Laser at λ=337.1nm, emission spectra are quite narrow, 7nm at 460nm emission wavelenth.关键词：surface emission microcavity;polymer122|99|0更新时间：2020-08-11
- 摘要：The spectrum narrowing of poly (9-butylfluorene)(PBF) was studied and conformed the stimulated emitting phenomenon in PBF films, named laser action. The energy threshold of emitting laser in PBF film with ～1μm thikness was at 8～15μJ/cm2.关键词：poly(9-butylfuorene);photoluminescence;spectrum narrowing107|87|0更新时间：2020-08-11
- 摘要：In accordance with the model of a symmetric metal-clad waveguide structure of five layers (metal-buffer-waveguide-buffer-metal) in devices of poled polymer waveguides, the propagation loss of the light propagating in the waveguide, due to the optical absorption by metal-clad layers, has been calculated and analyzed theoretically. The relation curves among the refractive indices and the thickness of the waveguide and the buffer layers has been presented under the condition of single mode. The optimal parameters for the metal-clad poled polymer waveguides can be determined on the basis of the calculating result.关键词：poled polymer;waveguide;optimal design108|133|1更新时间：2020-08-11
- 摘要：GaN crystalline have been grown by low pressure MOCVD. The optical properties and its relationship with the densities of dislocation have been studied. It has been investigated that the photoluminescence spectrum of GaN near interface showed as a broaden emission band and some narrow peaks. The broaden band emission may derive from the transition between shallow donor and dislocation related valance band tail. The excitation power and temperature dependence of photoluminescence intensities have been studied. The experimental results indicate that the narrow emission peaks origin from the deep-bound exciton and the dislocation may act as the bounding center.关键词：band tail;photoluminescence;exciton104|161|0更新时间：2020-08-11
- 摘要：Diamond films with various surface morphologies were obtained, which were deposited on pretreated molybdenum by microwave plasma-assisted chemical vapor deposition system. The films were characterised by X-ray diffraction (XRD), Raman spectrum, optical microscopy and scanning electron microscopy(SEM). The result of expe riment indicates that diamond films with ball-like graphitic surface morohologis, which consisted of diamond nulei, were obtained. By investigating electron emission of the diamond-amorphous carbon films, we found that the lower of the size of the ball-like graphitics in diamond-amorphous carbon thin films the most efficient of electron emission.关键词：diamond-amorphous carbon thin film;field electron emission;negative electron affinit106|82|0更新时间：2020-08-11
- 摘要：We fabricated Si-tips by dry etching 〈100〉 Si-substrate and by one step wet chemical etching 〈111〉 Si-substrate in solution of HF:HNO3:H2O=1.5:15:5. The radii of Si-tips’top about 10～20nm were gotten after experiment.关键词：Si-tip;cold cathode;dry etching;wet etching96|192|0更新时间：2020-08-11
- 摘要：With the rapid development of display technique, as a new digital image display device, LED display’s color is being more and more opulent. Now there is the full color LED display which displaying color is as good as CRT, but this display’s image data increases much. The increasing of data gives more pressure on the circuit of LED display, especially on the data transfer. Common solution is parallel transfer or increasing the transfer frequency. In this paper the application of data compression technoique in different LED displays was studied. Basde on the development of date compression technique and the features of LED display.关键词：LED display;data compression;transfer95|100|0更新时间：2020-08-11
- 摘要：This paper elecribes the structure, operating principle and operation insturction of a temperature-controlled intelligent annealing furnace whith high precision. The experimental results show that the temperature-control precision is±0.1℃. The intelligent anneling furnace has the following characteristics, such as without super regulating high precision, simple in determing parameter, etc. through using AI atrificial intelligence algorithmic approach, in which PID algorithmic approach is improved and retained in certain degree and the rules of fuzzy regulating algorithmic approach is added.关键词：annealing furnace;temperature-controlled;AI artificial intelligent103|91|1更新时间：2020-08-11
- 摘要：Energy transfer between phycoerythrin and chlorophyll A were studied by photoluminescences of laver, phycoerythr in and chlorophyll A, and calculated critical distance of energy transfer, or R0=3.45nm.关键词：laver;phycoerythrin;chlorophyll A;energy transfer94|129|0更新时间：2020-08-11
- 摘要：A new desighn consideration of the connection of semiconductor laser diode array and fiber array was reported. It can adjust and fix many laser diodes and fibers at the same time.关键词：semiconductor laser;fiber;array;connection91|119|0更新时间：2020-08-11
- 摘要：In this paper, ZnS:Cu, Br green ACEL powder phosphors were prepared on small scale. Effect of the atmosphere was investigated. The phosphors of different particle size were obtained. The brightness and lifetime of the ACEL were measured. The lifetime was improved with increasing the particle size.115|121|0更新时间：2020-08-11
- 摘要：In this paper, the soluble poly(2-methoxy-5-nonyloxy-1,4 phenylene vinylene) [MN-PPV] was synthesized by dehydrochlorination reaction. The eletroluminescence (EL) and photoluminescence (PL) of this sample were studied. The results showed that the eletroluminescence devices were stable. This indicated that the route of synthesis was available, too. The research of EL and PL for a series of soluble PPV derivatives are been doing.关键词：electroluminescence;solubility;PPV derivatives117|97|2更新时间：2020-08-11
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