Spectroscopy of High‐Energy States of Lanthanide Ions

Reid, Michael F.; Hu, Liusen; Frank, Sebastian M.; Duan, Chang‐Kui; Xia, Shuang; Yin, Min

doi:10.1002/ejic.201000182

Cited by 27 publications

(19 citation statements)

References 53 publications

(152 reference statements)

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“…The excitonic states may be modeled in a similar way to the 4f 13 5d excited states of Yb 2+ [11,12], with the 5d electron replaced by a more delocalized orbital. The broad band from 650 to 950 cm −1 may be attributed to transitions from the lowest exciton state that involves a change in the orbital of the delocalized electron, giving a change in bonding and therefore vibronic broadening.…”

Section: +mentioning

confidence: 99%

Impurity-trapped excitons and electron traps in CaF2:Yb2+ and SrF2:Yb2+ probed by transient photoluminescence enhancement

Senanayake

Wells

Reid

et al. 2013

Journal of Luminescence

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Section: +mentioning

confidence: 99%

Impurity-trapped excitons and electron traps in CaF2:Yb2+ and SrF2:Yb2+ probed by transient photoluminescence enhancement

Senanayake

Wells

Reid

et al. 2013

Journal of Luminescence

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“…The energy of the lowest 4f 6 5d 1 level is predicted to be $ 15,700 cm À 1 from this calculation, but it should be pointed out the uncertainty is of the same order as the assumed offset since the absorption maxima energies depend in a linear way on both the offset and the interconfigurational energy. Finally, we note that a more complete description of the 4f 5 5d 1 states would permit different bond lengths for the 4f 5 5d 1 (E) and 4f 5 5d 1 (T 2 ) states [20], but this has not been necessary here.…”

Section: Optical Absorption Spectrummentioning

confidence: 99%

Sm2+ fluorescence and absorption in cubic BaCl2: Strong thermal crossover of fluorescence between 4f6 and 4f55d1 configurations

Dixie

Edgar

Reid

2012

Journal of Luminescence

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“…We have recently proposed that two-frequency excitation experiments would provide more detailed information about the excited states and better test the calculations. 11 Excited configurations of rare-earth ions are not restricted to 4f…”

Section: -3 Transitions Involving Excited Configurations Such As 4fmentioning

confidence: 99%

Transient photoluminescence enhancement as a probe of the structure of impurity-trapped excitons in CaF2:Yb2+

et al. 2011

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We demonstrate a direct measurement of the energy levels of impurity-trapped excitons in CaF 2 :Yb 2+ . The radically different radiative decay rates of the lowest exciton state and higher excited states enable the generation of a transient photoluminescence enhancement measured via a two-step excitation process. We observe sharp transitions arising from changes of state of localized electrons, broad bands associated with changes of state of delocalized electrons, and broad bands arising from trap liberation. 14,15 Recent ab initio calculations have given valuable insight into the quantum physics of exciton formation.9 However, the broad bands provide no detailed information, and experimental information on the energy-level structure of impurity-trapped excitons is largely deduced from indirect measurements such as temperature dependencies, 16,17 pressure dependencies, 12 and photoconductivity. 18In this Brief Report, we report on an investigation of the internal structure of impurity-trapped excitons using twofrequency measurements of single-crystal CaF 2 doped with Yb 2+ . By applying IR radiation to the crystal after exciting it in the UV, we induce transitions between exciton states. Since some of the exciton-excited states have much higher radiative rates than the lowest exciton state, we can detect the excited state absorption by monitoring photoluminescence enhancement.CaF 2 :Yb 2+ crystals were grown using the vertical Bridgmann technique. The UV component of our two-frequency excitation was from a Quantronix TOPAS traveling-wave optical parametric amplifier (OPA) providing 3 ps pulses tunable in the 250-400 nm region of interest in this work at a repetition rate of 1 kHz. Pulsed infrared excitation was achieved using the Dutch free electron laser (FEL) FELIX in Nieuwegein. The IR output of FELIX consists of a 4-6 μs macropulse at a repetition rate of 10 Hz, containing micropulses at 25 MHz. FELIX is continuously tunable from 3 to 250 μm. The OPA was synchronized to the FEL, and the electronic timing between the two lasers could be varied. The UV and IR beams were spatially (but not temporally) overlapped on the sample, held at cryogenic temperatures within an Oxford instruments microstat helium flow cryostat. Visible fluorescence was detected using a TRIAX 320 spectrometer equipped with a C31034 photomultiplier. Our results for 365-nm-pulsed UV excitation of CaF 2 :Yb 2+ are consistent 113110-1 1098-0121/2011/84(11)/113110(4)

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Spectroscopy of High‐Energy States of Lanthanide Ions

Cited by 27 publications

References 53 publications

Impurity-trapped excitons and electron traps in CaF2:Yb2+ and SrF2:Yb2+ probed by transient photoluminescence enhancement

Impurity-trapped excitons and electron traps in CaF2:Yb2+ and SrF2:Yb2+ probed by transient photoluminescence enhancement

Sm2+ fluorescence and absorption in cubic BaCl2: Strong thermal crossover of fluorescence between 4f6 and 4f55d1 configurations

Transient photoluminescence enhancement as a probe of the structure of impurity-trapped excitons in CaF2:Yb2+

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