Showing papers in "Journal of Luminescence in 1989"

TL;DR: In this paper, the fluorescence quenching produced by the aggregates of the zwitter-ion and the cationic molecular forms of Rhodamine B in water and in ethanol is evaluated.

TL;DR: In this paper, the influence of the host lattice cation and anion on the position of the lowest 4f65d excited state are explained on the basis of a crystal field effect and a nephelauxetic effect.

TL;DR: In this article, the absorption and emission spectra and the emission lifetimes of Cr 3+ -doped LiCaAlF6 and LiSrAlF 6 were obtained by carefully accounting for the small non-octahedral components of the crystal potential field existing at the substitutional Al site.

TL;DR: In this paper, the two-dimensional and three-dimensional energy migration in EuB4O7 were analyzed using a random-walk model, and a value of 107 s-1 for the transfer probability of the excitation energy between nearest Eu2+ neighbours was derived.

TL;DR: In this paper, experimental and theoretical results on superlattice phonons in GaAs-AlxGa1-xAs structures are reviewed and a comprehensive analysis of resonance Raman studies for the investigation of exciton physics in quantum wells is presented.

TL;DR: In this article, it was shown that a broad distribution of activation energies will quite generally result in t-1 phosphorescence behavior for thermoluminescence (TL) glow curves, and the relationship of these derived effective values to the distributions actually used in the calculations is discussed.

TL;DR: In this paper, the authors review recent experimental and theoretical studies of the excitonic optical Stark effect in semiconductor quantum wells probed with femtosecond optical pulses, and present a theoretical analysis of the effect.

TL;DR: In this article, the authors compared the experimental spectra of Cr3+ ions in these garnets in terms of the symmetry and energies of the vibrational models coupled to the electronic states, and used fluorescence line narrowing to probe the broadening of the vibronic structure introduced by compositional disorder.

TL;DR: In this article, an efficient nonradiative pathway from 3T1g(t2g)2 to the ground state which bypasses the 1Eg emitting state was shown.

TL;DR: In this article, the effect of magnetic field on the exciton localization is discussed, focusing attention on the localized and the weakly delocalized regimes, and the possible mechanisms of the dephasing relaxation are the acoustic phonon-mediated intra-and inter-subband scattering, the Fano-type resonance between the light hole exciton and the heavyhole exciton continuum and the elastic scattering by the interface roughness.

TL;DR: In this article, the authors applied fluorescence anisotropy, excimer emission, nonradiative energy transfer and dependence of emission intensity on the polarity and rigidity of the medium to characterize various aspects of the dynamics of flexible chain molecules.

TL;DR: A survey of various methods of calculating the subband structures of semiconductor superlattices is given in this article, showing the complementary nature of the selfconsistent potential approach and the bulk-based empirical approach.

TL;DR: In this paper, the optical properties of a set of periodically structured samples covering a wide range of biaxially compressive and tensile strain are compared with those of lattice-matched In 0.53 Ga 0.47 As/InP structures.

TL;DR: In this article, the effects of a longitudinal electric field on optical properties of semiconductor quantum wells and superlattices were reviewed, emphasizing recent developments on the latter, such as the observation of the Stark ladder, field-induced localization, and change in the dimensionality of excitons.

TL;DR: In this article, the authors conducted a series of experiments in order to examine the nature of the energy transfer process between the Cr 3+ and Tm 3+ ions in YAG.

TL;DR: In this paper, non-exponential decays arising from the reabsorption of emitted photons are shown to be deconvolved by a sum of each contribution of the ith absorption-emission process whose mathematical expression is given by {ti−1/(i−1)!} e-t/Gt⊗l(t).

TL;DR: In this article, an apparatus is described which has been used to measure time-dependent luminescence spectra of samples under continuous laser excitation, which is useful in optical dating studies.

TL;DR: In this article, the authors showed that the random arrangement of Cl- and Br- around Sm2+ ions does not cause a detectable energy level splitting, but shifts the center of gravity of their energy levels.

TL;DR: Using a combination of optical absorption and laser selective excitation, an extensive set of energy levels has been established for the principal Er3+ center in CsCdBr3:Er3+, and Er3 + -vacancy-Er3+ arrangement as mentioned in this paper.

TL;DR: In this article, the authors present the results of some energy level calculations and cw optical experiments performed on biased GaAs-Ga(Al)As double quantum wells, and the emphasis is placed on the electric field dependence of electron, hole and exciton transfers from one well to the other.

TL;DR: In this article, the effects of the exciton-phonon interaction on the properties of quantum wells and superlattices are reviewed, including the phonon sidebands of the absorption and photoluminescence spectra.

TL;DR: In this article, the absorption and fluorescence emission of the chelating agent 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) and its complexes with Eu3+ have been measured in aqueous solution as a function of pH and concentration.

TL;DR: In this paper, the quenching is caused by electron transfer from the excited donor to the acceptor, and a new method of Stern-Volmer constants calculation based on the two-point Pade approximant is proposed.

TL;DR: In this article, the sharp line luminescence of a sample of GSGG: Cr3+ (Gd3Sc2Ga3O12) (dopant concentration 8.1×10+19 cm-3).

TL;DR: In this paper, the Eu 3+ ion in GdAlO 3 in the visible region was measured and it was verified that the splitting of the energy levels is according to the site symmetry, and polarized absorption techniques were used to check the nature of the dipole transitions and to determine the symmetry of the 7 F 0, 7 F 1 and 5 D J (J =0 to 2) energy levels.

TL;DR: In this paper, the diffusion coefficients of the electron and hole mobilities as a function of the superlattice period and the lattice temperature were investigated and shown to be similar in a super-attice and in the AlGaAs alloy with an equivalent Al concentration.

TL;DR: In this article, the authors used two quartz prisms mounted on a horizontal plate and moved into alternate positions, while the sample remains fixed, to minimize the effect of flashlamp instabilities in determining fluorescence decay profiles by the time-correlated single-photon counting technique.

TL;DR: In this article, the decay times of the emitting state of Cu+ ions have been compared with the value calculated from the UV absorption in the case of two Cu+-containing glasses.

TL;DR: In this article, the optical properties of the rare earth ions Er3+ and Tm3+ in a single crystal KCaF3 were investigated, and it was shown that rare earth ion entered the lattice readily and only one defect site for Er3+, compared to the many different sites that can be accommodated in other crystals.

TL;DR: In this article, the time and wavelength dependence of the Eu 2+ 5d-4f emission in BaFBr was measured over the extended temperature range 10-506 K.