最新刊期
卷 18 ， 期 2 ， 1997
- 摘要：CdS-ZnS strained layer multiple quantum wells have been fabricated on the(100)GaAs substrate by LP-MOCVD. The satellite peaks of X-ray diffraction indicate the existence of a good crystallinity MQWs. PL spectrum at 77 K shows the strong luminescence peaks at 365 nm and 385 nm respectively,which shift to high energy side about 0.8 eV compared to the CdS single crystal. It indicates the existence of the quantum confinement effect and large band shift caused by large strain.关键词：LP-MOCVD;CdS-ZnS strained layer multiple quantum wells;quantum confinement effect100|84|0更新时间：2020-08-11
- 摘要：In this paper,three-dimension display based on upconversion of ZBLANⅩⅣPr,Yb glass was-studied. Some-problems involved-were-discussed. Yb3+-ions-were used to sensitized-Pr3+-ions to-increase-efficiency of upconversion luminescence. Because that 960 nm laser can cause the monofrequency upconversion,in order to enhance the contrast of display,the intensity of 960 nm pumping laser was decreased.关键词：ZBLANⅩⅣPr;Yb;upconversion;three dimension display105|91|4更新时间：2020-08-11
- 摘要：The processes involved in the stimulated emission by photopumping in ZnCdTe-ZnTe multiple quantum wells have been investigated at 77 K. The energy differences(ΔE)between stimulated emission peak and exciton absorption peak at threshold(Jth)is about 19 meV. It is close to the exciton binding energy. The energy difference ΔE as a function of excitation intensities(J),in this experiments,can be express as ΔE∝J1/2.2,when excitation intensities are in 3Jth～4.8Jth. Considering the theoretical result ΔE∝J1/2.2,it is possible to think that the stimulated emission originated from exciton-exciton scattering processes when excitation intensities are in the above regions.关键词：multiple quantum wells;stimulated emission;exciton-exciton scattering131|85|1更新时间：2020-08-11
- 摘要：Light-emitting diodes(LEDs)having a ZnCdSe-ZnSe quantum well were grown by metal organic chemical vapour deposition(MOCVD)at a growth temperature of 430℃. Tert-butylamine(TBA)was used as a p-type dopant. ZnSe heterostructure diodes showed better voltage-current characteristics. The existence of ZnSe pn junction was showed by the electron beam induced current(EBIC)of a scanning electron microiscope. At 77K,blue-green light emission was observed at a wavelength of 465 nm at forward current.关键词：ZnSe pn junction;ZnCdSe-ZnSe QW;blue-green EL93|80|4更新时间：2020-08-11
- 摘要：There is a weak bulk coupling but a strong surface coupling between the electron and phonon for many polar crystals. In this paper,influences of the electron interaction with both the weak coupling bulk longitudinal optical phonons and the strong coupling surface optical phonons on the temperature characteristic of the surface magnetopolaron are discussed. The temperature dependences of the vibration frequency and the induced potential of the surface magnetopolaron are studied by using a linear combination operator method. Numerical calculation,for AgCl crystal as an example,illustrates that the vibration frequency and the induced potential will decrease with increasing temperature.关键词：surface magnetopolaron;vibration frequency;induced potential;temperature characteristic109|98|0更新时间：2020-08-11
- 摘要：The characterizations of exciton emission in ZnCdTe-ZnTe-MQWs under electric field have been reported in this paper. The changs of the exciton peaks in Zn0.67Cd0.33Te(6 nm)-ZnTe(6 nm)MQWs is very small,when electric field increases,peak position shifts about 1.5meV to the lower energy side,when voltage increases from 0 to 19V and peak intensity of this sample increases about 15%. In contrast,the n=1 heavy-hole exciton peaks of Zn0.8Cd0.2Te-ZnTe changed greatly as voltage increased from 6 to 8 V,exciton peak position shifts about 59%. The variation in exciton peak intensities between the two samples have been explained in exciton localization view point. The large shift of Zn0.8Cd0.2Te-ZnTe MQWs exciton peaks is due to the bigger quantum-confined Stark effect.关键词：multiple quantum wells;exciton localization;quantum-confined stark effect99|117|0更新时间：2020-08-11
- 摘要：Red and blue emitting porous silicon(PS)are obtained respectively through two kinds of air oxidization on the green luminescent PS. XPS investigation shows that the composition of red emitting PS are sillicon,SiOx(x=1～2)and some little fluoride and the blue emitting PS is mainly containing SiO2 and a little fluoride. IR transmition spectra show that the blue emitting PS almost only exists Si-O-Si peaks,but the red emitting PS not only mainly has Si-O-Si peaks and also has several obvious peaks of SiHx. It is suggested that the blue emission of PS comes from some defect centers in SiO2.关键词：porous silicon;luminescence;X-ray photoelectron spectrum123|297|1更新时间：2020-08-11
- 摘要：Solid solution semiconductor(ZnxCd1-xS)doped sillica glasses were prepared by sol-gel process and in-situ technique. The absorption edge of above materials shift to short wavelength direction with increasing of Zn contents. The increase of heat treatment temperature is benefit to format of perfect microcrystallite. The photoluminescence spectra excited by short laser pulse consist of two parts: the first at about 500 nm is produced by recombination of electrons and holes which are trapped in the acceptor or donor energy level,and second at about 600 nm is raised from recombination of surface state and defect,also the former is distributed over longer wavelength range which shift to short wavelength direction with increasing of Zn contents,and the intensity of later is reduced by increasing of heat treatment temperature.关键词：photoluminescence;solid solution semiconductor;absorption edge99|99|6更新时间：2020-08-11
- 摘要：The Bragg reflective characteristics of light propagating in ZnS/ZnSe periodic stratified structure have been analysed and calculated on the basis of light propagating theory in multilayer media.From the curves of relation between Bragg reflectivity and wavelength,it is found that the peak values of the Bragg reflective curves will deviate from the original positions with the ZnS/ZnSe refractive index increasing or decreasing.The deviative direction is related to the index change sign. It shows that a new "optical control switch" or "optical logical devices" can be achieved and applicated in the opticalintreconnection or opticalcomputer logical devices. The corresponding experiments will be reported later.关键词：period stratified media;stratified grating.109|139|0更新时间：2020-08-11
- 摘要：In this paper,the basic constructure and working theory of IOAOSA were given. We presented the fabrication technology of integrated optical components and guided wave acousto-optical modulator on integrated chip and we also presented the technological main points of making an organic whole sample.关键词：spectrum analyze;acousto-optic modulate115|131|0更新时间：2020-08-11
- 摘要：The complex Eu(p-PBA)3phen1/2H2O(pPBA:p-phenylbenzoate,phen: 1,10-phenanthroline)strongly fluoresces under the ultraviolet laser excitation. Excitation and luminescence spectra were recorded at 77 K. Two distinct sets of 5D0→7FJ luminescence spectra show that there are two Eu(Ⅲ)sites in the complex. Raman bands of asymmetric and symmetric stretching vibrations of the coordinated carboxylate groups are split and broadened,that indicates the carboxylates are coordinated to the europium ion in more than one modes.关键词：europium complex;high-resolved spectrum(HRS);Raman spectrum125|127|0更新时间：2020-08-11
- 摘要：A single layer structure electroluminescence devices-based on poly(p-phenylene vinylene)with two kinds of electron injection electrodes of aluminum and calcium were fabricated,of which electroluminescence emission can be observed in normal lit room. An interesting experiment phenomenon was observed. EL spectrum band depends on metal electrode. The ratio of intensity of the peak at 550 nm to that of the peak at 510 nm is changed as a work function of metal electrode. The reason to the different ratio was analyzed as compared the precesses of electroluminescence with photoluminescence. It is more clear of physical processes of the linear relationship of current density and brightness by an analysis in mathematics.关键词：metal electrode;poly(p-phenylene vinylene);electroluminescence130|191|1更新时间：2020-08-11
- 摘要：The photophysical properties of PyTS have been studied by steady-state absorption,fluorescence emission and time-resolved transient absorption spectroscopies. PyTS has a high fluorescence quantum yield in water,Φ-=0.54. The PyTS triplet state lifetime we obtained is 3.5 ms from nanosecond transient absorption spectra,its long lifetime is much favourable for excited energy transfer to other molecules as a sensited molecule. It maybe occurs a two photon absorption process which leads to PyTS cation transient absorption at 460 nm and 505 nm when PyTS-was excited. Here we also proposed the dynamic scheme of PyTS from the experimental results.关键词：pyrenetetrasulfonid acid tetrasodium salt;transient absorption spectrum;two photon absorption process;dynamic scheme191|183|2更新时间：2020-08-11
- 摘要：The fluorescence-of Cu+ and Eu2+ coactivated CaS is reported. The emission bands of Cu+and Eu2+ peaking at 430 nm and 630 nm were originated from Cu+ transition of Cu'Ca-Vs2+ centers and 5d-4f transition of Eu2+,respectively. The dependence of luminescence properties of Cu+nd Eu2+ on their concentration was investigatad. The emission of Eu2+ is sensitized by Cu+ and the peak wavelength and intensity of Cu+-emission band are affected by Eu2+. The experimental results indicate that there exists effective energy transfer from Cu+ to Eu2+ in CaS host. CaS·Cu+ and CaS·Eu2+ are good red-light transition agent and blue-light trasition agent for farm film,respectively. The absorption spectrum of chlorophyll photosynthesis can be imitated-by light transition film for farm using CaS·Cu+,Eu2+ phosphor as additive,Which can make the crops growth in the environment of function spectrum of the best growth of plants,and promote its growth or increase yield.关键词：CaS·Cu++Eu2+;photoluminescence;lmitation;chlorophyll;photosynthesis180|321|29更新时间：2020-08-11
- 摘要：In the study of extra-large LED video image display,the image quality depends on many factors,such as luminance,colors,image contrast,visual angle,etc. This paper emphasizes the increase of the image contrast and presants a method for improving the visual quality of video image.关键词：contrast sensitive;random reflection;transparence125|165|2更新时间：2020-08-11
- 摘要：In this paper,we first presented the third-order optical nonlinearity and excited state relaxation process of phycocyanin using degenerated four-wave mixing(DFWM)and time-resolved degenerated four-wave mixing. The χ(3) value of phycocyanin is 1.2×10-11 esu. By fitting its response curve of time-resolved DFWM,we obtained its relaxation lifetime is 308 ps. The third-order optical nonlinearity and excited state relaxation of phycocyanin come from the reaction among its submolecules or pyrrole molecules.关键词：phycocyanin;χ(3) value;excited state relaxation120|128|0更新时间：2020-08-11
- 摘要：The CdS nanocrystals were grown in the SiO2 molecular sieve by physics vapour transport for the first time. The PL spectra were measured at 77 K. The position the width and-the intensity of the emission band changed with increasing the growth time. These phenomena showed the formation process of CdS nanocrystal in SiO2 molecular sieve. The emission band narrowing and confinement effect were observed.关键词：SiO2 molecular sieve;CdS nanocrystal;topotaxy129|119|3更新时间：2020-08-11
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