最新刊期
卷 4 ， 期 1 ， 1983
- 摘要：Photoconductivity (PC) excitation spectrum of ZnSe:Mn has been studied. At room temperature it is different from the PC excitation spectrum of ZnSe without Mn. There are two peaks in ZnSe:Mn located at 4600Å and 5380Å, but in ZnSe only one peak is located at 4600Å. (see Fig.1).The two peaks of ZnSe:Mn have different temperature dependence. At 100K the peak of 5380Å gets very weak, but the peak of 4600Å nearly does not change(see Fig.2).The temperature dependence of PC under 4400Å and 5200Å excitation respectively has been studied.102|84|0更新时间：2020-08-11
- 摘要：ZnS:Cu,Nd,Cl thin films have been shown to give good DCEL with spectrum characteristic of trivalent neodymium ions. Nd3+ ions form stable luminescence centers and can directly convert electrical energy into optical energy with efficiency of~10-4W/W.The thin films have two parallel electrodes consisting of a semi-transparent mirror formed by the conducting SnO2 on the glass and a completely reflecting gold back electrode. These parallel electrodes form an ideal cavity for producing the oscillations of a given wavelength emission.More attentions are paied to the transitions from excited state 4F3/2, to ground state 4I9/2 with production of the emission at ~900nm and to state 4I11/2 with production of the emission at ~1080nm. In these two spectral groups,some sharp spectral lines increase more quickly with applied voltage than the common spectral lines. These results are attributed to a tendency of population inversion involving the excited state 4F3/2 and sub-levels of the ground states 4I9/2 and 4I11/2 and then to an occurrence of stimulated emission in the suitable harmonic oscillation cavity formed by two parallel electrodes.The experimental results reported here show the possibility of fabricating a thin film laser device in II-VI compounds doped with rare earth ions.91|42|0更新时间：2020-08-11
- 摘要：Terbium activated simple phosphates of lanthanum, yttrium, and gadolinium are cathodo-,UV photo-,and roentgeno-luminophors.As regard to the double phosphates there was only one article written by D'Silva[4] relating to the study of roentgenoluminescent properties of the system yttrium gadolinium phosphate.In this work samples of terbium activated yttrium gadolinium phosphate system Y1-xGdxPO4:Tb were prepared by solids state reaction of corresponding metal oxides and ammonium hydrophosphate in the presence of flux sodium pyrophosphate.Their luminescent properties under the excitation of cathode rays,UV light,and X-rays have been investigated. A possible mechanism of concentration quenching of activator terbium ions has been postulated.Figures 1-1,1-2, and 1-3 show the cathode-,UV photo-,and roentgeno-luminescence spectra.They all consist of a set of sharp emission lines corresponding to the 5D3-7EJ and 5D4-7FJ transitions of terbium.In 5D3-7FJ transitions the 5D3-7F6(λ=382nm)is the strongest one.In 5D4-7FJ transitions the 5D4-7F5(=544nm) is the strongest one.100|61|0更新时间：2020-08-11
- 摘要：Boric anhydride (B2O3) is a compound rather strong in acidity. At given temperatures, it can be co-soluble with the metal oxides of alkaline earth, alkali, molybdenum or vanadium, and yeild glassy or solid solutions. In this experiment, europium yttrium boratovanadate phosphor has been synthesized using yttrium boratovanadate as the host and europium as the activator. Photoluminescence behaviour has been studied.Appropriate experimental conditions for synthesizing the phosphor and optimal compositions for luminescence, (Y0.94Eu0.06) (V0.69B0.01)O3.7, were found out. Adding small amount of rare-earth impurity, e.g.Gd2O3, Sm2O3, has little effect on or a slight enhancement of the europium luminescence under 365nm excitation. However, adding luminescent compounds such as Zn2GeO4. GeO2:Mn and SrLaBO4:Pb has markedly enhanced the europium luminescence. This is ascribed to the overlap of the emission bands of the added compounds with the absorption bands of europium. Adding Bi3+ to the phosphor results in a great increase of the luminescence intensity. The excitation band of Bi3+ -containing sample is broadened with peak shifted toward the longer wavelength side. The emission band of Bi3+ peaking at 539nm can be seen in the emssion spectrum (fig. 3). The increase of the luminescence intensity is therefore attributed to the summing up of the Bi3+ and Eu3+ emission.The peak of the excitation band of Eu3+ is at 326nm, corresponding to the excitation transition of the cluster VO43-, and the band may overlap with excitation band of the charge transfer state of Eu (fig. 1,2). Besides, lines at 383, 396, 418, 467 and 539nm in this band correspond to the excitation from 7F0 to 5D4,5L6, 5D3, 5D2, 5D1.The emission spectrum of Eu is composed of the lines at 594, 610, 616, 619, 699 and 705nm, the most intense ones are at 616 and 619nm, corresponding to the transition from 5D0 to 7F2.By the investigations of the emission spectra of the sample under different temperatures, it is pointed out that the optimal temperature for luminescence is about 350℃ (fig.5). The effect of temperature on luminescence depends on the energy absorption by the host and Eu, as well as on the increased efficiency of energy transfer from the host to Eu. Below 350℃, the luminescence intensity increases rapidly with the increasing temperature; above this temperature, the decrease follows. It is supposed that Eu can be efficiently excited by ultraviolet light to the charge transfer state(4f72p-1). With the increase of temperature, the charge transfer state lowers down and the absorption band shifts toward longer wavelength side, nearer to the excitation wavelength 324nm of VO43-; whereas the lowered energy level gets nearer to the 4f excited state, thus increase the probability of relaxation to the 4f excited state (the number of phonons corresponding to the energy difference between the two states decreases) resulting in the increase of luminescence intensity. Again, the most important factor is the broadening of the excitation and emission band of VO43- with the increase of temperature, thus increase the overlapping part of the two bands and increase the energy transfer efficiency. Similarly, the absorption band of Eu is also broadaned with the increase of temperature and so increase its overlap with the emission band of VO43- and increase the efficiency of energy transfer from VO43-to Eu3+ resulting in the marked in'crease of lumineicence intensity. However, when the temperature outruns 350℃,thermal quenching begins to play a marked role in the luminescence and causes the luminescence intensity to decrease gradually.96|41|0更新时间：2020-08-11
- 摘要：Cerium pentaphosphate,CeP5O14,is an ultrafast scintillator,which has a uv-emission band with an extremely short lifetime (about r1=12nsec.).Ce3+ in cerium pentaphosphate has a broad uv-absorption band.So it can be used as sensitization ion. We have investigated a new crystalline luminescence material, CeP5O14:Mn, which can emit strong green-yellow light.A series of CeP5O14:Mn crystals were grown from phosphoric acid by the evaporation solution method. The usual experimental conditions are as follows:The manganese carbonate (purity:A.R.) is added to a gold crucible, in which G.R.-grade commercial orthophosphoric acid, H3PO4, containing 15% by weight of water, is filled. As the manganese carbonate has been dissolved completly, the cerium oxide (purity:99.99%) is added into the solution.This mixture is heated in the crucible to about 250℃ and kept for about two days until the excess water has evaporated and the cerium oxide has dissolved. Subsequently the temperature is raised to about 550℃. After a week the crucible is taken out and the mother liquor is poured out of the crucible. The crystals are rinsed in hot water repeatedly. The CeP5O14:Mn crystals, colourless or with a pale yellow colour could be obtained.CeP5O14:Mn crystal compositions were determined by chemical analysis. No obvious change in Ce% content was observed when Mn% content was small. The structure of CeP5O14:Mn crystal was determined.When the content of Mn% in the crystal was low, the crystal structure of CeP5O14:Mn was the same as that of CeP5O14, both belong to the monoclinic system, space group P21/c. Some lattice parameters of CeP5O14:Mn were calculated by a computer. The results are shown in table 1.The CeP5O14:Mn crystals emit strong green-yellow light when they were excited by 254nm ultraviolet light.The luminescence intensity increases with the increase of Mn% content. CeP5O14 emits ultraviolet light and no luminescence of LaP5O14:Mn was observed.The results indicate the energy transfer from Ce3+ to Mn2+ exists.The absorption spectra show that CeP5O14 has a strong absorption peak in the wavelength range of 255-320nm, LaP5O14:Mn has a weak peak at 290nm, and when CeP5O14 is doped with manganese, the absorption peaks move toward the shorter wavelength side and a split of absorption peak were observed (fig.1).The excitation spectra of CeP5O14:Mn has been measured. The excitation peak of CeP5O14:Mn is the same as that of CeP5O14. The intensity of the strongest peak shown at 302nm decreases as the content of Mn% increases.The emission spectra of CeP5O14:Mn under excitation of 302nm show three groups of emission peaks at about 332, 545, and 665nm. But CeP5O14 has only one group peaking at about 332nm, so the other two groups peaking at 545 and 665nm are considered as emission of manganese ion.An interesting phenomenon was observed, as the content of Mn% was increased, the emission intensity at 545nm was increased, while that at 685nm was decreased. As shown in fig,4 and fig,5,101|50|0更新时间：2020-08-11
- 摘要：In the ordinary process of preparation of blue-emitting phosphor (BaEuMg)3Al14O24,fluoride compounds are found to be effective in decreasing the preparation temperature and obtaining good luminosity. However, the residue of the fluoride in the phosphors always results in apparent decay.An improved method in which boric acid is used as a flux instead of the fluoride is presented here. In comparison with the ordinary process the maintenance of the phosphor is obviously improved while the preparation temperature and luminosity keep unchanged.135|49|0更新时间：2020-08-11
- 摘要：In this paper the spectrometric function of the monochromator is abstracted mathematically as the function of the slit width. The spectrometry of phosphor chromaticity by four steps in view of system engineering theory is studied.103|72|0更新时间：2020-08-11
- 摘要：In this paper the effect of antireflective coating (ARC) on the emitting facet on the light power output of edge emitting diode is reported.In high speed GaAs/GaAlAs DH-LEDs with sputtered A12O3 as AR coating on the front emitting facet, a remarkable increase in light power output has been achieved. The fabricated LEDs have two types of structure:normal edge emitter and edge emitter with optical waveguide structure.A conventional rf sputtering equipment with the source power of 3kW at 13.5 MC was used in preparing the A12O3 AR coating (refractive index 1.65~1.7). A high purity A12O3 disk was employed as a target.Before sputtering the high-purity Ar gas was further purified by passing it through molecular sieve 5A and hot Ti coils.The light power output of a normal edge emitter as a function of current density is plotted in Fig.3.At a driving current density of 4kA/cm2, the light power increases from 370nW for the uncoated LED to 495uW for the same diode coated with~1890Å A12O3.This corresponds to a light-power increase of~34%.103|29|0更新时间：2020-08-11
- 摘要：P-Ga0.47In0.53 As contact layer (Zn-doped) was grown by supercooling in YW-1 type furnace with a carbon-slider beat, under a Pd-purified hydrogen ambient. In order to grow Zn-doped InxGa1-xAs layers lattice matched to InP by LPE, using a constant arsenic concentration in the liquidus (XAs1=5.7at.%), the influence of the composition of solution XGa1 and XZn1 on the lattice mismatch of GaxIn1-xAs/InP heterojunction [Aa/a=(aGaxIn1-xAs-aInp)/aInp] have been investigated. The growth temperature Tg was kept at 632℃ in all cases. The lattice mismatch was measured by a doublecrystal x-ray diffraction method.The lattice mismatch as a function of growth solution composition XGa1, and XZa1 have been shown,respectively.It is found that surface morphology is poor, if the lattice mismatch of epi-layer at the room temperature is more than 5×10-4;but the wafer with a smooth surface is obtained,if the lattice mismatch of epi-layer has a negative value,even though its value is as high as the order of magnitude of-10-3. Because the lattice mismatch at the growth temperature is more than that at the room temperature.97|38|0更新时间：2020-08-11
- 摘要：The author gives a review on the principle and some characteristics of laser photochemical techniques for use in the micrometer-sized processing, and presents possible applications of the techniques to microelectronics and their developments in the future.135|69|0更新时间：2020-08-11
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