最新刊期
卷 11 ， 期 1 ， 1990
- 摘要：In order to study energy transfer by means of cw excitation, concentrationdependence of fluorescence intensity of sensitizer is discussed in this paper.188|120|20更新时间：2020-08-11
- 摘要：The luminescecnee of the Al2O3 type Ba-rich hexaaluminale 1.30BaO·6Al2O3 activated with Ce3+, Pb2+ and Sn2+ is investigated. Emission and excitation spectra show the existence of two different activator centers for all these ions in the Ba-rich compound. For 1.30 BaO·6Al2O3:Ce3+, the emission spectrum of Ce3+ ions is consisted of four bands, the relative intensities of which are independent on the activator concentration, indicating that no energy transfer takes place between two different Ce3+ centers. For the Pb2+- or Sn2+-activated compounds, fluorescence spectra contain three bands, 390nm, 425nm and 485nm for Pb2+ and 388nm, 418nm and 457nm for Sn2+, lespectively. The bands of 425nm and 390nm (or 418nm and 388nm) are attributed to Pb2+ (or Sn2+ ) ions, situated in the crystallographic BR and anti-BR sites, lespectively, whereas the bands of 485nm and 457nm are ascribed to pairs of Pb2+ and Sn2+ ions, respectively, whereas to their increasing intensities relative to the other two bands with increasing Pb2+ and Sn2+ concent. The formation of the ion pair is compared with data reported in the literature for SrAl12O19:Pb2+ and is shown to be due to the interaction between the activator ions occupying the BR and anti-BR sites in the same mirror plane. Besides, the luminescence properties of Pb2+ and Sn2+ are dhcussed in the light of the energy scheme of Sn2+ ions.97|44|0更新时间：2020-08-11
- 摘要：The luminescence emission of C band in InP has been studied. The InP samples used in this study were grown by LPE or MOCVD methods. The substrate materials are divided into class A, B, C and D according to the intensity of near band edge luminescence peaks. The MOCVD layers were grown under different conditions including different temperature and M-Y rate. The LPE layers were grown under phosphorus overpressurc with saturated In-Sn melt. The infrared spectra were observed at the temperalurc of 77-30CK with a Kr ion laser as the excitation source and a Ge-detectoi cooled to 77K as the detector. The peak of C band in InP observed in this work is located at 1.08eV and the Spectrum band is broad and weak. It was observed that the C band emission peak shifted slightly to high energy side when the samples were doped heavily. We found that the intensity of C band emission peak depended on the growth conditions and that the intensity of C band in LEP InP decreased if proper component parameter for In-Sn melt was chosen. The experiment result that the C band emission may be observed in both MOCVD and LPE InP samples is consistent with the assumption that the C band is due to lattice defects in InP. By changing the phosphorus pressure during the LPE processes the intensity of C band varies, which is one of the evidences that C band is related to phosphorus defects. The activation energy 0.17eV obtained from temperature dependence of spectra equals to the half of the energy between the deep level, measured directly from C band luminescence, and the top of the valence band. This relationship is expected if a short range potential 6-function replaces, the Coulomb potential in theoretical calculation. The temperature-dependent spectrum results are simulated using quantum mechanics configuration coordination model and the parameters S=8 and hv=0.02eV. It means that a larger Franck-Condon shift exists for C band in InP.124|77|0更新时间：2020-08-11
- 摘要：The complex fluorides xMF2-yYF3(M=Ba,Sr,Ca;x=1,2,3;y=0,1,2,3,4,5) were synthesized with successive firing of 15-20hr in a stream of high purity argon (0.51/min) in the temperature range of 800-900℃.112|45|6更新时间：2020-08-11
- 摘要：A series of M'0.2M"2.6Ce0.2(PO4)2 phosphors were synthesised by solid state reaction. X-ray diffraction patterns have proved that M'0.2M"2.6Ce0.2(PO4)2 belongs to monoclinic system, space group P21/n; M'0.2M"2.6Ce0.2(PO4)2 belongs to hexagonal system, space group R3e; and M'0.2M"2.6Ce0.2(PO4)2 and M'0.2M"2.6Ce0.2(PO4)2 belong to the same structure, hexagonal system,space group R3m. When alkalin ion is varied, the structure type is not changed for the tame alkaline-earth metal system.123|48|3更新时间：2020-08-11
- 摘要：The phosphors of LnAlO3 doped with Ce3+, Tb3+, Dy3+ were gynthetized by solid state reaction at 1200℃. BaF2 was used as a flux. The luminescence of Ce3+, Tb3+, Dy3+ and the sensitized luminescence of Ce-Tb, Ce-Dy in LnAlO3 (Ln=La, Gd or Y) were systematically investigated. It is shown that with different Ln, the influence of the LnAlO3 host on the luminescence of activators is different.109|55|0更新时间：2020-08-11
- 摘要：Because photochemical hole burning (PHB), population hole burning and photon echo are all performed on zero-phonon line (ZPL), it is useful to study ZPL and vibrational mode.We have obtained the absorption spectrum of tetraphenyporphin (TPP) in cellulose acetate film at room temperature which contains four bands peaking at 649, 594,552 and 516 nm respectively. They originated from the absorption transition of TPP, while host cellulose acetate does not contribute to this range of the absorption spectrum. The band centered at 649 nm is ZPL of TPP (0-0 transition) and its FWHM is about 2Cnm.By fitting the experiment data of the ZPL with Lorentzian and Gaussian line shapes respectively, it is shown that the ZPL is close to Gaussian. The ZPL is inhomogeneousely broadened.106|98|0更新时间：2020-08-11
- 摘要：Photodynamic cancer therapy (PDT) is a hopeful means to tieat cancer. Instead of HPD, recently some new photosensitizers have been developed. Among them phthalocyanine (PC) are most noticed, because it is pure chemical, rather stable, and is absorbed more strongly in red region (the best penetration wave-band of human tissue).After we synthesized sulfonated aluminum phthalocyanine (AlSPC) in our laboratory and found out its photokilling ability to human liver cancer line (SMMC-7721), the continuous study on photosensitization of SMMC-7721 cell line with AlSPC using fluorescence technic is reported in this paper.106|70|1更新时间：2020-08-11
- 摘要：The chemicd and kinetic properties of singlet molecular oxygen in liquid phase have attracted much attention of chemists and biochemists owing to its involvement in many chemical and biological processes. This transient entity, however, had evaded direct observation until a decade ago when the 1270nm luminescence from the forbidden tiansition 1△gO2(v=O)→3∑g-O2(v=O) was detected via photosensitization in solution. The success of this measurement was achieved by using germanium photodiode (with much highei sensitivity in the infrared legion than in the visible region in contrast to photomultipliei tubes) coupled to fast, high-gain amplifiers. However,Ge photodiodes satisfying the measurement of ultra-weak 1270 nm band of O2(1△g) are not yet available in our country. Based on the results of Krasnovsky in direct observation of singlet oxygen emission at 1270 nm with red-sensitive PMT, it is of interest to see the feasibility to detect the (1,0) transition emission of O2(1△g) at 1070 nm by using PMT of S-1 photocathode with a spectral response ranging from 300 to 1150 nm, and a successful demonstration of this proposed approach is described in this paper.108|45|0更新时间：2020-08-11
- 摘要：When a trace of impurity Mn2+ is a codopant in ZnS crystallite and ZnS:Cu phosphor, the hyper-fine structure spectra of the electron spin resonance of Mn2+ ions in the crystallites are monitored. With these spectra we can study the phase transition from cubic (β phase) to sixfold (a phase) lattice of ZnS and ZnS:Cu prepared by different calcining temperature. Therefore the trace of Mn2+ is a sensitive paramagnetic probe for structure transformation.118|61|3更新时间：2020-08-11
- 摘要：A new a-SiC:H/pin potential well structure visible-light injection-electroluminescent device has been designed. The band gaps of p and n a-SiC:H layer are larger than that of i layer, so the injection carrier can be confined in luminescent active i layer.Two types of samples,potential well structure and potential barrier structure devices, were prepared under same conditions. Results of the measurement of electroluminescence intensity versus injection current show that potential well structure is better than potential barrier structure. Transient electroluminescence was also measured. The electroluminescence has a delay time that decreases as the pulsed excitation current increases. Luminescence lifetime is about 0.3μs. It doesn't vary with the excitation current.121|81|1更新时间：2020-08-11
- 摘要：It is achieved to obtain 1.3nm double carrier confine(DCC) structure semiconductor lasei with high T0 by using general LPE technique. Composition matching of two active layers, doping concentration and growing condition are strictly controlled. The radiative recombination probability of super hot carriers which are generated by Augei recombination and leaked from the first active layer is increased, so that the carrieis leaking into InP clad layer are decreased, The T0 of DCC structure InGaAsP/InP semiconductor laser is as high as 150K in the operating range of 293-343K. The relationship between spontaneous emission spectrum and injected current density for DCC lasei is discussed. The influence of the composition matching of active layeis and the thickness of thin sandwich layer on the threshold current density and T0 is analysed.112|79|0更新时间：2020-08-11
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