最新刊期
卷 6 ， 期 3 ， 1985
- 摘要：Zinc sulfide and zinc-cadmium sulfide are widely used as host materials for the blue and green phosphors in kinescopes and other color display tubes.To achieve good luminescence yield and efficient deposition of the phosphor on the screen during tube manufacture it is essential to control the shape and the size distribution of the phosphor particles.For zinc sulfide and zinc-cadmium sulfide materials this can be done by carefully controlling the reaction conditions during the preparation.In this work,the requirements for growth of uniform particles have been investigated.The analysis and experimental results are presented below for zinc-cadmium sulfjde material of composition,Zn0.9Cd0.1S,grown under the prescribed conditions.112|59|0更新时间：2020-08-11
- 摘要：The purpose of this paper is to investigate infrared transtions of Er3+ and Tm3+ ions and energy transfer between them in LaOBr material.Jouart has studied energy transfer between Er3+ and Tm3+ ions in cadimium fluoride crystals[1].But there are no publishes about energy transfer between Er3+ and Tm3+ ions in rare earth material in the infrared region so far.Here we present the results for energy transfer between Er3+ and Tm3+ ions in the LaOBr material for the first time.We find that there are a number of luminescence lines of Er3+ and Tm3+ ions jn the infrared region from 0.8μ to 2.0μ by the excitation of 5145Åor 4880Åof argon laser.They come seperately from four energy levels of Er3+ and Tm3+ ions.The intensities of fluorescence of Er3+ and Tm3+ ions strongly depend on the concentration of Er3+ and Tm3+ ions.Coresponding to emission lines from different energy levels of ions,the laws of concentration quenching are different.This kind of self-quenching phenomenon may be related with the interactions of multipolar cross relaxation of Er3+ and Tm3+ ions energy levels.Our results provide an information to look for the best doping-con-centration of infrared transitions of this kind of material.140|39|0更新时间：2020-08-11
- 摘要：In the present paper,we report excitation spectra of the free exciton emission on high purity ZnSxSe1-x single crystals at x=0.02 and 0.125.Results indicate that the exciton migration is reduced by the excjton-localiza-tion induced by the atomic scale compositional-fluctuation of S and Se atoms within the exciton radius.Highly pure ZnSxSe1-x single crystals are grown by the sublimation method.Sample surfaces are carefully etched and cooled to 2 K by immersing it into liquid helium.Grating-monochromatized light beam from a 2 kW Xe-1amp(FWHM-1 meV)is utilized for the excitation source.The resulting excition luminescence lines are analyzed by a J.Y.U-1000 double mo-nochromator.105|42|0更新时间：2020-08-11
- 摘要：This paper first reports that the mechanism of electroluminescence(EL)excitation in ZnS:Tm thin film(TF)is different from that in ZnS:Er and ZnS:Tb TF.It appears that excitation energy transfers from some impure centers to Tm ions.The ZnS:Tm TF with ITO-Y2O3-ZnS:Tm-Y2O3-A1 structure is made by electron-beam evaporation.During the evaporation the vacuum pressure,the evaporation rate of ZnS:Tm layer,and the substrate temperature are 5×10-5 torr,200Å/min,and 160℃-200℃ respectively.The optimum Tm3+ ion concentration is approximately 2% by weight and the thickness of ZnS:Tm layer is in the range from 400nm to 600nm.119|90|0更新时间：2020-08-11
- 摘要：ZnS is one of the most popular luminescence material in the electroluminescence(EL)application,and it is the most promising material for the blue EL devices.Because of it's wide energy band gap(3.6eV)and directive transition characteristics,it can be used to fabricate different colour EL devices with whose visible region by doping various impurities.In this paper,ZnS single crystal with high quality grown by chemical vapour transportation with Iodine is described.First,powder ZnS precipitation is purified in Ar and H2S mixed gas at 1100℃ for 10-20 hrs.to improve the stoichiometry and increase the size of the ZnS particals.Then,both purified ZnS and lodjne powder are put jnto a vessel separately.148|129|0更新时间：2020-08-11
- 摘要：The gain coeff.and the spectra of gain coeff.are discussed in this paper.The gain coeff.,as one of the important parameters about the emission properties of semiconductor laser,is not only dependent on the transition probability but also dependent on the difference of the density of filled conduction band states and the density of empty valence band states.The transition probability is related to both the factor of energy gap and the factor of the spin orbjt splitting.The spectra of gain coeff.are measured under three different injection conditions:the direct current injection;the pulse current injection;and the direct and pulse current injection.Under the condition of pulse current injection,the thermal effect can be neglected as the width of pulse is shorter than 0.3μs.The peak of gain coeff.is moved towards the shorter wavelength with increasing of injection pulse current.This is due to the fillins of upper conduction band states and the empty of lower valence band states.Under the condition of direct and pulse current injection,the total injection current is kept constant,but the magnitude of components are changed.The peak of gain coeff.is moved towards longer wavelength with increasing of direct current component.That is due to the thermal effect on the active area.Under the direct current injection the peak of gain coeff.is kept constant because of the thermal effect and the filling effect introduce the movement of the peak of gain coeff.in contrary direction.This experimental result is in agreement with the theory.125|112|0更新时间：2020-08-11
- 摘要：This paper reports the results on the synthesis of LaOI and the study of the luminescence of several rare earth ions in this host.If cautions on oxidation were taken,LaOI could be prepared by usual flux method successufully.166|64|0更新时间：2020-08-11
- 摘要：Solvent effect on the absorption spectra,fluorescence spectra and fluorescence quantum yield were studied.In particular,the fluorescence quantum yields for Rh6G in hydrogen bond solvents were discussed.By using variation excited methods the fluorescence quantum yields were approximate.The linear variation between the fluorescence quantum yield of Rh6Gsolutions and the polarity(ε-1)/(2ε+1)of the solvents was found.It was alsofound that the same relationship between the fluorescence quantum yields,lifetimes and the polarity(ε-1)/(2ε+1)in ANS.Fluorescence quantum yields forRh6G and ANS in hydrogen bond solvents decreased with increase of solvent polarity(ε-1)/(2ε+1).The solvent effect on fluorescence quantum yield for Rh6G in hydrogen bond solvents could be interpreted by the energy dissipation.In the case of strong interaction between the molecules Rh6G and the hydrogenbond solvent molecules with high(ε-1)/(2ε+1),the energy dissipated quickly.Whereas in those low(ε-1)/(2ε+1)solvents,the energy dissipated less rapidly.This paper's results show that the η2/3(η-viscosity)dependence,which was first proposed by Forster and was experimentally verified for the quantum yield and fluorescence lifetimes of several triphenyl methane dyes,did not coincide with Rh6G in hydrogen bond solvents as well as ANS solution.131|86|0更新时间：2020-08-11
- 摘要：In this paper the effects of composition on the optical properties of the LnxRE1-xP5O14(Ln:Pr3+Nd3+,Er3+;RE:La-Lu,Y,Sc;x:0.1-0.9)have been studied.A mixed RE pentaphosphates with high RE concentration as new was explored.The spectra absorption,fluorescence and infrared were measured.The fluorescent lifetimes of LnxRE1-xP5O14 crystals and many regular results have been obtained.114|39|0更新时间：2020-08-11
- 摘要：Influence of stripe geometry on the properties of GaAs-GaAlAs edge emitting LED.'s is described in this paper.The output power,near field pattern,beam divergence,coupling efficency and frequency response can be improved as the stripe width is reduced.A calculation of the effect of stripe width about the lateral current spreading and optical field distribution has been made.The agreement obtained between calculation and experimental results is very good in our cases.Devices with very narrow stripe width tend to heat up the device and cause a rapid saturation of power as the current is too crowded.Since the lateral light intensity spreading increases as the stripe width is reduced,a preferable stripe width is about 10 to 15μm.Through a reasonable compromise,edge-emitting diodes with more than 100μW output power at the end of a standard GI fiber pigtail at low injection current of 100mA has been obtained.Optical bandwidth of more than 100MHz is also achieved at some current level.The highest emitting power obtained is 130μm with a bandwidth of 136MHz at 100mA driving current.94|60|0更新时间：2020-08-11
- 摘要：The heterojunction phototransistor(HPT)is a new type of optoelectronic device which has got rapidly development recent years.It can be used as a good detector in a longer wavelength range competing with Ge and Ⅲ-Ⅴ compound APD.Furthermore,there are several special functions,such as optical bistability,switching and amplification,by means of combination or integration of HPT and other semiconductor devices.For instance,DH laser etc.The operating mechanism and some properties of HPT are introduced in this paper.It is shown that HPT's can provide a much larger optical gain without the high bias voltage necessary as APD and without excess nois due to avalanching effects.This results from its heterostructure emitter and."window" effect.The interesting characteristics and some recent progress in GaAlAs/GaAs and InGaAsP/InP HPT are reviewed.It is believed that the characteristics of HPT could be improved by improving design and fabrication technique of devices.115|49|0更新时间：2020-08-11
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