最新刊期
卷 17 ， 期 2 ， 1996
- 摘要：In this paper we present a model which accounts for the emission lineshapes observed in chromium doped disordered systems.The model takes into consideration both the site distribution and the admixture of the E and T states through spin-orbit coupling.The calculated lineshapes are in good agreement with those observed in Cr3+ doped mullit ceramics,Cr3+ doped silicate glass and Cr4+ doped MgCaBa aluminate glass.关键词：chromium ions;state admixture;lineshape105|65|1更新时间：2020-08-11
- 摘要：The investigation to energy transfer between Tm3+ and Er3+ ions in a ZBLAN glass has been made.The energy transfer under excitation of different pumping wavelengths is of difference.Effects of Tm3+ ions are to lower the fluorescence intensities of 2H11/2 and 4S3/2 of Er3+,and to enhance the fluorescences of 4F9/2 and 4I11/2,that is,the population of high-lying energy levels has been moved to the low-lying states.Under certain circumstances,the fluorescence of 4S3/2 is quenched completely.关键词：energy transfer;fluorescence of Er3+;fluoride glass92|60|1更新时间：2020-08-11
- 摘要：High temperature oxidized porous silicon has been investigated.Three peaks can be seen on the cathodeluminescent(CL)spectrum.The intensity of these peaks decreases fast with electron irradiation.For poor photoluminescent(PL)sample,the PL intensity enhances obviously after electron irradiation.The IR and Raman spectra of high temperature oxidized porous silicon show that whose strueture is mainly SiOx.Further analysis shows that three peaks may come from the luminescence of defect centers in SiOx.As electron irradiation,some other defects are generated in SiOx.This makes the CL intensity decrease and only through these defects the luminescent centers can be excited by UV light,therefore the sample’s PL intensity is increased.关键词：porous silicon;cathodeluminescence;high temperature oxidized;defect center102|78|0更新时间：2020-08-11
- 摘要：Some properties of a surface polaron both,strongly and weakly coupled with acoustic phonons via the deformation potential for 2D nonpolar crystals in magnetic field are studied.The ground state energy of the surface magnetopolaron is derived by the method of a linear combination operator and a Lagrange multiplier.The magnetic field dependence of vibration frequency, ground state energy and the effective mass of the surface magnetopolaron in 2D nonpolar crystals are discussed.关键词：2D nonpolar crystals;deformation potential;acoustic phonon;surface magnetopolaron119|67|0更新时间：2020-08-11
- 摘要：ZnS:Mn electroluminescent thin films were prepared by metal organic chemical vapour deposition(MOCVD)technology.ZnS:Mn thin films are cubic crystal phase.Crystal directions are identical and grains are bigger.The average size of ZnS:Mn grains is 150.7 nm.The micro-surface of the thin film is smooth.(100)main peak of hexagonal crystal phase has not been found on ZnS:Mn X-ray diffraction spectrum.So it is elimined that ZnS: Mn thin film prepared by MOCVD may be hexagonal crystal phase.Mn2+ ions are uniform distributed in the thin film except for the edges. In which the content of Zn2+ and Mn2+ ions are higher.Possible reason is that the ions are piled up on dislocation,which is produced on edge areas during the initial and the final growth stage.In addition,the amount of the piled Zn2+,Mn2+ ions on the initial growth stage are more than ones on the final growth stage as a result of effection of the substrates and variability of stoichiometry.The piled layers are not beneficial to electroluminescence of ZnS:Mn thin film.It should be diminished by optimum experimental conditions.关键词：MOCVD;thin film;crystallinity;Mn2+ distribution109|67|0更新时间：2020-08-11
- 摘要：Photoluminescence and electroluminescence were observed under low temperature from step graded index SiGe/Si quantum well grown by molecular beam epitaxy.The SiGe/Si step graded index quantum well structure is beneficial to enhance its light emitting efficiency. The optical and electrical properties of this structure were discussed in this paper.关键词：SiGe/Si quantum well;photoluminescence;electroluminescence114|78|0更新时间：2020-08-11
- 摘要：Several majority and minority peaks with apparent activation energy within a range of 0.6-0.7 eV appeared on the DLTS spectra of Ni+-implanted n-GaP annealed at different conditions.The band-bendings and space profilling changes of the concentrations of NiGa impurity in its different charge states within the doping layers during the zero-reverse bias process have been calculated for the samples.Combining an analysis of the thermal emission rate data of the levels,a discernment on which, among the DLTS peaks observed experimentally,could be caused by Nic. center has been made.100|62|0更新时间：2020-08-11
- 摘要：LEC grown GaP S doped single crystal samples were heated-treatment from room temperature to 1000℃ with interval of 50℃ and Ar was used as safeguarding gas.The defects in GaP samples were investigated with Positron Annililation Technology(PAT) and Scanning Electron Microscopy(SEM).The experimental results indicate,point defects and dislocations exist in GaP.The composition of defects changes with heat-treatment temperature.The results of PAT investigation express that positron annililation lifetime can decompose into two parts.As the heat treatment temperature were raised, its lifetime of capture component τ2 at first increases from 310 ps into 330 ps,then decreses into 280 ps.Intensity of capture component make corresponding change with temperature raised.It reflect that concentration of defects make relevant change with the temperature.关键词：GaP;defects;positron lifetime122|62|0更新时间：2020-08-11
- 摘要：Low loss surface strip wave guide fabricated by Ag+-Na+ ion exchange technology on highqualityf BK7 glass is reported in this paper.The mode field distributed curves of strip waveguide were measured by near-field method.It is shown that dismatch loss of coupling between fibre and waveguide is 0.54 dB,the transmission loss of the waveguide is 0.21 dB/cm. And 1×2 and 1×4 single mode waveguide splitter used for large capacity coherent optical communication were produced.关键词：strip waveguide;ion-exchange;couple100|86|0更新时间：2020-08-11
- 摘要：In this paper properties of InAsPSb epitaxy grown using both lowering and constant temperature LPE methods are studied.The solid composition of epitaxial layer was determined by EPMA analysis.The experimental result indicates,that the P and Sb content have almost a contant value for the epilayer grown by the constant temperature LPE method.The diodes were driven by current pulses with 10μs duration and 1 kHz.The laser emission with wavelength 3.09 μm was observed from single heterojunction made of p-InAs0.82P0.12Sb0.06,and n-InAs substrate at 12 K.104|72|0更新时间：2020-08-11
- 摘要：Lead-tin-fluorophosphate glasses doped with fluorescein and acridine red are reported,and compared with sol-gel glasses doped with fluorescein and acrieine red.It is found that the lead-tin-fluorophosphate glasses are better than sol-gel glass,in the former,there are some new phenomena which can be explained by heavy atom effects.关键词：lead-tin-fluorophosphate glasses;sol-gel-glass;fluorescein;Acridine red115|90|4更新时间：2020-08-11
- 摘要：Four 2-arylbenzothiazole compounds have been synthesised.All the compounds show fluorescence. From the fluorescence excitation spectra of compounds of Ⅰ、Ⅱ、Ⅲ and Ⅳ, it is seen that each spectrum has three excitation bands,two shorter wavelength excitation peaks are always at 310 urn and 360 nm respectively; nother longest excitation band is located at different positions for different compounds. The longest excitation bands and emission spectra of compounds Ⅱ,Ⅲ and Ⅳ occur red shift in comparison with the longest excitation band and emission spectrum of Ⅰ because of the interaction between donor and acceptor in compounds Ⅱ and Ⅲ or the enhancement of conjugated degree in Ⅳ.关键词：2-arylbenzothiazole;conjugated degree;luminescent property107|86|1更新时间：2020-08-11
- 摘要：The synthesis and optical properties of ZnS:Mn nanocrystallites were investigated.By measuring absorption spectra,we analyze the size and size distribution changing with time duration. The emission from Mn2+ was detected and analyzed.112|61|1更新时间：2020-08-11
- 摘要：The excitonic optical bistability in ZnSe-CdZnSe MQWs optical bistable device has been studied on reflection at room temperature for the first time.The research result indicates that the threshold and contrast ratio for the optical bistability in ZnSe-CdZnSe MQWs optical bistable device are about 180 kW/cm2 and 6:1,respectively.The major nonlinear mechanism for the optical bistability is due to the phase space filling of excitonic states and excitonic band broadening.112|67|0更新时间：2020-08-11
- 摘要：GaN has been grown on(0001) Al2O3 substrates by APMOCVD.Carrier concetration of GaN is 2.3×1019cm-3.Hall mobility of GaN is 320 cm2/V·s.The minimum FWHM of (0001) peak of double crystal X-ray diffraction is 12’.The photoluminescennce of GaN has been observed.111|56|0更新时间：2020-08-11
- 摘要：A thin film electroluminescence device,using 4,4’ -bis(3-methylphnelphenylamino)biphynel(TPD)as a hole transporting layer,tris (8-quinolinolato)aluminum(Alq3)as an electron transporting layer and Mg·Ag metal as a back electrode,gives a good duribility.The half-life period of initial luminance 106 cd/m2 is 120 hours under a continuous driving,and it still maintain the luminance 38 cd/m2 even at operation time beyond 500 hours.101|83|3更新时间：2020-08-11
- 摘要：Abstract R. F. chemical vapour deposition(CVD)polycrystal diamond films have been observed to emit electrons, current density of 1 mA/cm2 with an intensity sufficient to form an image,at an applied electrical field of 25 V/μm.106|72|0更新时间：2020-08-11
- 摘要：Abstract The characteristics of current-voltage and electroluminescence of C-phycocyanin (αβ)3 from spirulina platensis have been investigated in air. It is found that C-PC is of strong electroluminescence,and the positions of the electroluminescence peaks shift a little to red upon the increased applied voltages.111|77|1更新时间：2020-08-11
- 摘要：Abstract Poly-phenylquinoxaline(PPQ)was firstly used as electroluminescent material and the polymer thin film electroluminescent devices were fabricated by means of spin coated method.After mixing with 1,3,5-triphenyl-2-pyrazoline(TPL),the color of devices was changed (blue shift).The optical and electrical properties of PPQ thin film were measured.The devices can be driven by both positive and negative voltage(or alterna ting voltage) even though the current-voltage curve approximately possesses diode property.93|62|2更新时间：2020-08-11
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