Time-Resolved Vacuum Ultraviolet Spectroscopy of Er3+ ions in the SrF2 Crystal

The photoluminescence and photoexcitation spectra as well as the luminescence decay kinetics of Er3+ ions in the visible ultraviolet and vacuum ultraviolet (VUV) regions have been studied by the method of low-temperature, time-resolved VUV-spectroscopy on excitation by synchrotron radiation. In the VUV spectral region of the luminescence of SrF2:1% Er3+, the 146.5-nm band with a time of decay of less than 0.6 nsec was revealed together with the well-known emission band at 164.3 nm (decay constant in the microsecond range). Its possible nature is discussed. The specific features of the formation of photoexcitation spectra of the f-f and f-d transitions in the Er3+ ion are considered. Competition between the processes of excitation of f-f and d-f luminescence has been revealed. It manifests itself in the inverse relationship of their photoexcitation spectra in a range of energies of incident photons that are close to the position of the 4fn-15d configuration levels. © 2005 Springer Science+Business Media, Inc.This work was carried out with the support of grants from the Russian Fundamental Research Foundation (05-02-16530), "Universities of Russia (UR 02.01.433), Ural Scientific Center Promising Materials" CRDF (EK-005-XI), and partially from BMBF (05KS8GMD/1)

Vacuum Ultraviolet Excitation of Rare-Earth ion Luminescence in Strontium Fluoride Crystals

The photoexcitation spectra (70-280 nm) of the Eu 3+, Tb 3+, Dy 3+, Er 3+, and Tm 3+ ion luminescence in strontium fluoride crystals are studied at 8 and 295 K by vacuum ultraviolet spectroscopy using synchrotron-radiation excitation. The processes of transfer of the excitation energy to the impurity centers as well as the relaxation mechanisms of the excited high-energy states of the rare-earth ions are analyzed. The bands corresponding to the interconfiguration 4f-5d transitions and the charge-transfer bands are identified in the photoexcitation luminescence spectra. ©2005 Springer Science+Business Media, Inc.The present work was supported in part by the Russian Foundation for Basic Research (Grant 05-02-16530), by the Program “Russian Universities” (Grant UR.02.01.433), by REC-005 (ЕК-005-XI), and BMBF (05KS8GMD/1)

Prompt and delayed secondary excitons in rare gas solids

Direct and indirect creation of excitons in rare gas solids has been investigated with reflectivity and luminescence spectroscopy. For the heavy rare gas solids Kr and Xe, new and more reliable exciton parameters have been deduced. With time-resolved luminescence spectroscopy, fast and delayed secondary-exciton creation has been established and separated. Thermalization of photocarriers and their delayed recombination have been analyzed, including a first attempt to investigate the influence of excitation density on the carrier dynamics. The existence of excitonic side bands of ionization limits Ei (either band gap or inner-shell ionization limits) in prompt secondary exciton creation has been established. The threshold energies of these side bands are given by Eth≈Ei nEex (n is integer, Eex is exciton energy). The side bands are ascribed to the formation of electronic polaron complexes, superimposed to inelastic scattering of photoelectrons

5d-4f luminescence of Ce3, Gd3 and Lu3 in LiCaAlF6

The emission and excitation spectra as well as decay kinetics of luminescence due to 5d4f transitions in Ce3, Gd3 and Lu3 ions doped into LiCaAlF6 crystals have been analyzed with high spectral and time resolution using synchrotron radiation for excitation. The rich fine structure originating from electronic origins of transitions and their phonon replica has been well resolved and identified. Experimental data are compared with the spectra simulated in the framework of the semiphenomenological models of the crystal field and the crystal lattice dynamics. © 2011 Elsevier B.V. All rights reserved

Vacuum-ultraviolet 5d-4f luminescence of Gd3+ and Lu3+ ions in fluoride matrices

The VUV 4 f n-1 5d-4 f n luminescence and luminescence excitation spectra of Gd3+ (n=7) in LiGdF4, GdF3, LiYF4: Gd3+, and YF3: Gd3+, and of Lu3+ (n=14) in LiLuF4, LuF3, and LiYF4: Lu3+ have been analyzed with high spectral resolution. In systems with intermediate electron-phonon coupling, zero-phonon lines, and phonon sidebands were observed. The excitation spectra of dilute systems exhibit rich fine structure originating from electronic origins of transitions and their phonon replica. Theoretical calculations explicitly taking into account a microscopic model of the crystal field and the crystal lattice vibrational spectra agree well with experimental data and are the basis for a safe analysis of the spectra. © 2007 The American Physical Society

Luminescent VUV Spectroscopy of Er3 + and Tm3 + Ions in Strontium Fluoride Crystals

Emission and excitation spectra as well as decay curves of Er3 + and Tm3 + ions doped into SrF2 crystals have been studied using time-resolved vacuum-ultraviolet spectroscopy under pulsed synchrotron radiation at 8 K. In emission spectrum for crystals doped with Er3 + ions together with well-known emission caused by spin-forbidden 4 f10 5 d → 4 f11 transitions (decay constant in the microsecond range), a new fast emission band detected at 146.5 nm (decay constant is less than 0.6 ns) has been revealed. It was shown that excitation spectra of f-f and d-f emission bands for Er3 + and Tm3 + ions in SrF2 have opposite behaviors in the spectral range corresponding to energy of their 4 fn - 1 5 d configurations. These peculiarities and energy transfer mechanisms were analyzed. © 2006 Elsevier B.V. All rights reserved.This work was supported by RFBR (05-02-16530), REC-005 (EK-005-XI), program Universities of Russia (UR.02.01.433), Estonian Science Foundation (grant 6538) and BMBF (05KS1GUD/1)