最新刊期
卷 14 ， 期 4 ， 1993
- 摘要：Optical absorption, emission and excitation spectra, lifetime of 5S2 state from 10K to 660K for Ho3+ ions in fluoride glass and the Raman spectrum of fluoride glass were measured. The radiative transition probabilities of Ho3+ in fluoride glass were calculated from its absorption spectrum on the basis of Judd-Ofelt theory. The nonradiative transition probabilities of 5S2 state from 10K to 660K were determined by the calculated radiative transition probability and the mesured lifetimes of 5S2 state at different temperatrues. With phonon energy determined from Raman spectrum, it is found that if only one kind of phonon were considered there could be no way to conform with the experimental results, while if phonons with two different frequncies, as well as the influnce of Huang’s factor are taken into account, fairly good fitting could be obtained.The Huang’s factor is estimated from the fitting of the theory to the experimental results. The effect of Huang’s factor on nonradiative transition rates is discussed.关键词：multiphonon nonradiative transition;multi-frequency mo-del;Huang’s factor107|68|1更新时间：2020-08-11
- 摘要：ZnSe-ZnS superlattices(SLS) are grown by MOCVD on (100) GaAs substrstes, following the deposition of a 1μm-thick ZnS buffer layer. Each sample is composed of 50 ZnSe wells of thicknesses Lw=8nm and 50 ZnS barries of thicknesses Lb=8nm, respectively. The samples are stuck on clear glr.ss so that the GaAs substrate material is exposed. The GaAs substrate is mechanically lapped to a thickness of 200-300μm and then etched a light window with a selective chemical etch.Three light windows, on which the thicknesses of SLS and ZnS are 0.8 and 1μm,respectively, are obtained on the same sample after chemical etching hole and their absorption spectra are measured at room temperature. It is found that the excitonic absorption properties of three holes are the same although the qualities of surface of grown layer near to GaAs are not same because of effect of chemical etching on its growth layer. The one of three light windows is cleaved and the etching depth is measured by using SEM. It is found that the existence of ZnS buffer layer protects the excitonic properties of SLS layer because the etched depth is less than thickness of ZnS buffer layer.The light window area of 3×3mm2 with grown layer of l.8μm in thick have been obtained by anodization methode for the first time. Microscope observation (×120) shows the light window surface near to GaAs is very smooth. The 300×300μm2 multiple arraies on the ZnSe-ZnS SLS of 3×3mm2 have been carried out recently. This result shows it is possible to obtain the integration of optical switching and optical computing devieces in ZnSe-ZnS SLS.109|82|1更新时间：2020-08-11
- 摘要：The fabrication technology in quantity of GaAlAs single heterostructure red LED’s has been investigated in detail. A growth boat with new structure has been designed to carry out simultaneous LPE growth on many substrates. An effort has been made to obtain the optimum solution composition and the best growth parameters. A growth process for epitaxial wafers with excellent proformance and good reproducibility has been established. The LED’s dices fabricated by this process have emission wavelength of 660mm, mean brightness of 4.5mcd at 20mA and the highest value of 6.2mcd.关键词：red LED’s;GaAlAs single heterostructure106|89|0更新时间：2020-08-11
- 摘要：In the study of MIM (Metal-Insulator-Metal) LETJ (light-emission tunneling junction), we adopted SAW (Surface Acoustic Wave) instead of surface roughness and fabricated MIM LETJ in the field of SAW. As a result, the LETJ’s efficiency, intensity and stability have been advanced obviously.In this paper, we introduce the LETJ’s basic structure and technology, explain its light-emission theory, discuss its Ⅰ-Ⅴ characteristics curve and spectrum,devise a new type of switch on the basis of negative resistance phenomenon.关键词：MIM tunneling junction;SPP wave;SAW124|58|1更新时间：2020-08-11
- 摘要：3 Kinds of coal dust sample which were obtained from different region and rank were detected by chemiluminescence (CL) in the environmet of increasing oxygen. Except one group, the results showed that there are remarkable or very remarkable difference on the emission peak value and average value between groups of sample and group of control and so do groups of sample one another. The CL of coal dust samples were affected significantly by grinding on sample and density of oxygen. The mechanism of CL of coal dust was discussed.关键词：coal dust;chemiluminescence;free radical97|84|0更新时间：2020-08-11
- 摘要：Glasses doped with CdSxSe1-x microcrystallies, whose size is smaller than the exciton Bohr radius, were made. This kind of materials has obvious quantum confinement properties and large third-order nonlinear optical effects by studying their linear spectra and saturated absorption.关键词：semiconducter microcystallies;saturated absorption;nonlinear optics107|76|0更新时间：2020-08-11
- 摘要：The red shift of the green emission band of ZnS:Cu, Br phosphors has been observed in (Zn,Cd)S:Cu,Br phosphors with different concentration of CdS.The green ACEL phosphors were made by general way. CdS was diffused into the green ACEL phosphors at temperature 600-700℃ for 1/2 hour-one hour. Five yellow ACEL phosphors have been obtained.The brightness of these five phosphors 706-2、 706-3、 706-4、 706-5 and 706-6、 are 16, 21.4, 18.5, 9.8, 2.5cd/m2 respectively, when a sinusoidal electric field 50Hz and 220V is applied. The concentration of CdS in these phospors are 0, 3, 10, 17, 23, mol% respectively.The lattice stucture of all ZnS and (Zn, Cd)S phosphors were determined by X-ray analysis. It show that hexagonal strucure is increased with the concentration of CdS being increased.Electroluminescent properties including bringhtness, emission spectra, deterioration and the dependent of frequency for the luminance have been studied also.关键词：phosphors;electroluminescence;low temperature diffusion93|71|0更新时间：2020-08-11
- 摘要：The near-infrared electroluminescence spectra of GaP pure green (PG) light-emitting diodes (LEDs) were studied at room temperature (300K) and liquid nitrogen temperature (77K). Many overlapping broad emission bands were observed in the luminescence spectra. The spectra were fitted with Gaussian lineshapes and can be decomposed into six Gaussian peaks. Finally the origins of the deep level luminescence bands in the GaP PG LEDs and the influence of deep levels on the luminescence intensities of the LEDs were discussed.关键词：near-infrared electroluminescence;deep level;light-emitting diode111|92|0更新时间：2020-08-11
- 摘要：In this paper, the optical properties of BiI3 semiconductor colloids were investigated. The absorption spectra of BiI3 colloids and I2-alcohol solution were compared. It is verified that the absorption of BiI3 ultra-fine particles is covered by the strong absorption of I3- ion. In the emission spectra of BiI3 colloids, the luminescence due to hexadecyl-pyridine was observed. Because of energy transfer between surface of BiI3 micro-crystals and hexadecyl-pyridine, we observed the absorption of BiI3 microcrystals by measuring the excitation spectra. The size distribution calculated by measured data is in good agreement with theoretical one. The experimental results indicate that there exist profound quantum size effects in BiI3 colloids.关键词：ultrafine particles;quantum size effect;photoluminescence98|70|0更新时间：2020-08-11
- 摘要：A series of TiO2 ultrafine particles (UFP) coated with a layer of stearic acid radicals were synthesized. It is found that the apparent optical band gap decreased and the red shift of optical absorption band edge increased as the diameter of TiO2 UFP coated decreased.关键词：particle diameter;TiO2 UFP coated with stearic acid radicals;apparent optical band gap;red shift of optical absorption band edge127|53|2更新时间：2020-08-11
- 摘要：The fluorescent conditions of fluorescein, the effect of concentration, temperature and pH value on the hydrolysis of four fluorescein esters (diacetate, dipropanoate, dibutyrate and dihexanoate)are studied in this article. The mechanism of hydrolysis of the four esters in the presence of lipase is also discussed and the optimum conditions is ascertaired. The experimental results obtained show that fluorescein dipropanoate possesses highest lipase hydrolysis efficiency and latent application in future.关键词：fluorescein;fluorescein esters;lipase;hydrolysis121|92|0更新时间：2020-08-11
- 摘要：Fluorescein monopyhosphate was synthesized with fluorescein and phosphorus oxychloride. The monophosphate was applied to the fluoro-metric analysis of acidic phosphatase. The reaction conditions of phos-phatase with fluorescein monophosphate, linear range for determination of the phosphatase, detection limitation and Michaelis constant were studied.关键词：fluorescein monophosphate;acidic phosphatase;fluoro-metric method105|67|0更新时间：2020-08-11
- 摘要：Release of ATP/ADP from platelets causes enhanced oxygen radical species responses in polymorphonuclear leukocytes stimulated by FMLP or zymosan. The effect of platelets and adenosine nucleotides on production of oxygen radical species of polymorphonuclear leukocytes is concentration dependent. Platelets exert a priming effect on the generation of oxygen radical species at low platelet-to-PMN ratios but also have an inhibitory of effect on oxygen radical species production from PMN when higher platelet-to-PMN ratio are used. Identical biphasic effect were also observed when ATP or ADP was substituted for platelets.关键词：polymorphonuclear leukocytes;platelet;oxygen radical species;chemiluminescerce;respiratory burst149|80|0更新时间：2020-08-11
- 摘要：GaAs rib waveguide interferometric modulator with Schottky-barrier electrodes have been fabricated in n-/n+ GaAs by reactive ion etching and lift off mask techniques. The device total losses was 11.2 dB. An extinction ratio of-24.2 dB, and half wave voltage of Vz=21V was obtained for single-mode optical systems operationg at 1.3 μm. The device principle, fabracation and character are introduced.99|75|0更新时间：2020-08-11
- 摘要：InGaAs matched to InP substrate was grown epitaxially By Low Pressure Metalorganic Chemical Vapour Deposition (LP-MOCVD) using TMGa, TMIn and AsH3. The effect of growth temperature on the composition, growth rate, the photoluminescence (PL) intensity and Full Width at Half Maxium (FWHM) have been studied by PL (at 15K), Xray double diffraction and scaning electron microscopy (SME). At an optimum temperature 635-640℃, InGaAs of very good properties can be grown.109|114|2更新时间：2020-08-11
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