最新刊期
卷 10 ， 期 3 ， 1989
- 摘要：Calcium metasilicate is a kind of practicable luminescence host.A new phosphor which is Ce3+ activated CaSiO3 was prepared by a solid state reaction at high temperature. The emission and excitation spectra of CaSiO3:Ce3+ were investigated at liquid nitrogen temperature and at room temperature. Under ultraviolet or cathode-ray excitation CaSiO3:Ce3+ phosphors show a considerably strong bluish-purple emission consisting of two overlapping bands with peaks at about 396nm and 430nm,respectively.With a energy separation of about 2000cm-1, these two bands correspond with the transition of the lowest-5d state to the 2F5/2 and 2F7/2 terminal levels.The excitation spectrum of Ce3+ in CaSiO3 distributes in the region from 230nm to 380nm, which is a broad band at least consisting of three overlapping subbands. These bands rise from the ground state to different 5d levels splited by the crystal field and from different Ce3+ ions positioned at distinct Ca2+ sites.This Ce3+-activated phosphor shows a very fast fluorescence decay. The fluorescence lifetime of Ce3+ in CaSiO3 rs approximately 30ns with' excitationof a 337.1nm laser pulse with a width of 6ns at room temperature.In the paper, the influence of preparing condition, Ce3+ concent ration, crystal structure as well as charge compensator on the luminescence properties of Ce3+ are discussed.107|60|4更新时间：2020-08-11
- 摘要：Annealing and quenching are the most efficient ways for electroluminescent materials to improve their maitenance. The reason why annealed and quenched phosphor has a long lifetime is not yet clear.By making the investigations on the emission spectrum, thermoluminescence and ion probe, it is found for the first time that the distribution of copper in a phosphor particle is changed by annealing and quenching. The copper is concentrated in a small region near the surface during quenching, And these regions correspond to copper sulfide segregation. Therefore, the reason why the annealed and quenched phosphor has a long lifetime may be considered to be that the copper sulfide segregation is stabilized by annealing and quenching, and the ZnS-Cu2S junction is formed. The distribution of electric field in a particle must be stringly deformed and concentrated near the surface. The field strength and potential barrier are increased and the condition of initial electron injection is improved, Thus the degradation of ACEL phosphor is alleviated,96|77|0更新时间：2020-08-11
- 摘要：ZnSe has the potential to be used to make blue LED because it has wide band gap, and its strong blue exciton luminescence is observed even at the room temperature[1]. The main obstruction in practice is that the p-type ZnSe with low resistivity is difficult to produce due to self-compensation. It seems that the self-compensation effect is related to the native defects originating in nonstoich-iometry during crystal growth[1]. The two electron traps which are located at 0.30 and 0.33eV (labeled as A and B thereafter) below conduction band are commonly observed in ZnSe. Some authors suggested that these traps be associated with Se vacancies[3,4].98|63|0更新时间：2020-08-11
- 摘要：The interdiffusion of the P-InP with TiPdAu and Au-Zn at interface has been investigated by Auger electron spectroscopy. The results incidate that Ti -and Pd layer as a diffusion barrier plays and important role. The TiPdAu layer is used as the P-electrode of InGaAsP/InP double heterojunction light emitting diodes. The InGaAsP/InP DH wafers were grown by LPE technique. It consisted of three or four layers. The first layer of n-InP was the buffer layer doped with Sn or Te 5-8μm;the second one was an undoped active layer (1-2μm); the third was confining layer of p-InP doped with Zn (2~3μm), and the last was Zn doped contact layer, with the plated Au as heat sink. The InGaAsP/InP DH LED's were soldered with In onto Au-plated heat sink. The reliability of devices were investigated at the room temperature, 70℃ and 85℃ with and without inject current respectively. The experiment was carried out in air. The I-V characteristics of the devices were measured during the aging test. The dark defect in the LED's were observed with an infrared line scanner.The results show that no change of the I-V characteristics is observed. It indicates that the InGaAsP/InP DH LED's made of the TiPdAu as p-electrode have high reliability. The devices made cf the Au-Zn as p-electrode or deep Zn diffusion are different from the devices made of TiPdAu as p-electrode. In the former the large DSD's are generated in the emitting area during aging.105|43|0更新时间：2020-08-11
- 摘要：Crystal field parameters for SmP5O14 crystals in the approximation of C2v point group symmetry and the reduced matrix elements(f5a SLJ//Uk//f5 a'S'L'J') were calculated.The crystal field parameters were fitted and the values of energy levels of Sm3+ ions were calculated. Beside these, calculated values of energy levels were compared with the experimental values which were measured from spectra.101|46|0更新时间：2020-08-11
- 摘要：In this paper, the luminescence properties of Dy3+, Sm3+ and Ce3+ in M3La2(BO3)<(M=Ca, Sr, Ba) are reported.106|27|4更新时间：2020-08-11
- 摘要：This paper reports that the long persistence phosphor pf MgF2:Mn2+ is synthesized successfully at 900C. Authors suggest the use of magnesium carbonate basic and ammouium fluoride as starting materials, and the relationship expressed by the reaction equation:Mg(OH)2·4MgCO3·6H2O+10NH4F-MgF2+12H2O+4CO2+10NH3 is studied as a function of preparation temperature. The optimum conditions for preparating the samples have been examined. It shows that the concentration of Mn2+ ion is about 0.5mole%.Emission spectra of MgF2:Mn2+ phosphor are measured from 400nm to 700 nm and that of a typical sample is shown in Fig.2. The emission color of the phosphor is orange-red with chromaticity x=0.599, y=0.438. The emission peaks for these samples occur at 590nm. The luminance varies with the voltage or current density (Fig.3 and Fig.4). The cathode luminescence characteristics of the samples are studied. Luminescence brightness and persistence of MgF2:Mn2+ phosphors are superior to P33 phosphors.124|50|0更新时间：2020-08-11
- 摘要：The physical characteristics of the light polarization and the fluorescence in human cerebrospinal fluid for the normal and un-normal cranial nerve centre system are shown in this paper. There is a very strong Raman band at Raman shift 3392cm-1 in the spectrum of human cerebrospinal fluid, originating from the vibration of O-H bond, with polarizing rate POH = 0. It is given that the vibration of O-H bond in human cerebrospinal fluid is completely symmetrical, and its polarizint intensity is isotropic.The polarizing rate of the fluorescence in normal and un-normal human cerebrospinal fluid are 0.69 and 0.74, respectively, thus it is proved that the molecule symmetry would be reduced when haman cranial neive centre system is out of order. Included angle10°31'10'' is estimated from the polarizing rate of the fluorescence measured.We have measured the lifetime of the fluorescence 5450Å in the normal and non normal human cerebrospinal fluid, they are both 8ns.Besides, the relation of the intensity-time of the fluorescence 5450Å are measured at 4880Å radiation for the samples of the normal and un-normal human cerebrospinal fluid. The curves(see Fig.2), will gradually approach a constant with time. We can obtain some good enlightements from those results -human vertebra end radiated by suitable wavelength of laser for curing some diseases of human cranical nerve centre system.105|76|0更新时间：2020-08-11
- 摘要：The blue-green emitting phosphor 2 (Sr1-xEux) 0 (1-n) P2O5n B2O3 was studied with laser-induced-fluorescence technique. Its luminescence lifetime and emission spectrum change with x and n are reported. The ranges for x and n are 0.001<x<0.1000 and 0.01<n<90 respectively,The luminescence properties of the phosphor as a function of temperature (room temperature to 400℃) are also reported. It provides an experimental basis for making up the most efficient phosphor.118|41|1更新时间：2020-08-11
- 摘要：A series of Rare Earth (R.E.) trifluoroacetate crystals [Re(CF3COO)3· 3H2O]2(Re = Eu,Gd,Tb,Dy) and [TbxY1-x(CF3COO33H2O]2 were prepared with hydrosolution method in room temperature; The crystal structure of this type of compounds has been determined with Nicolet R3M/E type Four Circle Diffractometer, which is monoclinic. The space group is P21/c. The R.E. trifluoroacelates have a dimeric structure [Re(CF3COO)3·3H2O]2, viz. Z = 2. The characteristic spectral properties of stoichiometry compounds CRe(CF3COO)3·3H2O]2 (Re= Eu,Gd,Tb,Dy) are discussed in detail. In the emission spectra, the Eu3+ shows 1,3,5 lines corresponding to 5D0-7F2,1,2 transition respectivly, where the 5D0-7F2 transition shows stronger emission at 612nm. The number and intensities of the lines are in agreement with C2 orCsUnder ultraviolet excitation, the red emission (612nm) of the Eu3+, the green emission (544nm) of the Tb3+, the blue (480-488nm) and yellow(572-577nm) of Dy3+, and ultraviolet emission (312nm) of Gd3+ are observed in this type of crystal.The spectral intensities of [TbxY1-x(CF3COO)3·3H2O]2 (x=0.05, 0.10, 0.15, 0.20, 0.25mol depend on the concentration of Tb3+. No fluorescence quenching occurs.96|64|0更新时间：2020-08-11
- 摘要：The present paper reviews the recent advent of cathodoluminescent materials which include the monochromatic orange, amber and; color high-resolution phosphors for terminal display tubes for special purposes, phosphors for color TV,projection TV and gigantic outdoor video display and" multicolor and multi-persistence penetration phosphors for multifunction CRT. The important properties of energy efficiency, color and CIE coordinate, beam current saturation effect, temperature dependence, presistence and degration are stressed. "It is interesting to develop the phosphor having saturated emission color and meduim-long antiflicker presistence.114|123|5更新时间：2020-08-11
- 摘要：An abnormal property of luminescence of ZnS:Eu2+ is reported.The excitation and emission spectra of ZnS:Eu2+ are shown in Fig.1. Both are wide bands peaking at 400 nm and 550 nm respectively. This indicates that the luminescence is due to f-d transition of Eu2+.The afterglow of the yellow emission was measured.It was surprising to observe that the decay turns out to be tens of minutes long and follow a power law I≅t-n with n=1.24 (Fig.2).Since f-d transition is an allowed one, the luminescence corresponding to it should have a very short lifetime, e. g. 1us. So it is believed that this long persistent afterglow must be due to the existence of some kind of electron traps, the origin and the nature of which are to be clarified.116|43|7更新时间：2020-08-11
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