Anharmonic metastable charge transfer vibronic exciton in potassium tantalate
Autor(en): | Liu, G.K. Vikhnin, V.S. Kapphan, S.E. |
Erscheinungsdatum: | 2005 | Herausgeber: | Institute of Physics Publishing | Journal: | Journal of Physics: Conference Series | Volumen: | 21 | Ausgabe: | 1 | Startseite: | 173 | Seitenende: | 176 | Zusammenfassung: | Charge Transfer Vibronic Excitons (CTVEs) are bi-polaronic excitons characterized by specific recombination luminescence. The latter has been investigated with respect to the influence of IR pumping and led to the experimental evidence of an non-linear CTVE. Such an essentially anharmonic CTVE with respect to the charge transfer and lattice displacements was predicted recently [Vikhnin, 2003 Solid State Commun. 127 2832], and should manifest a well-defined metastable behavior. It is shown that an IR pumping recalls practically the same CTVE-recombination emission band as that induced initially by a UVpumping. Such an effect is characterized by relaxation time τ after the UV-pumping (for example, τ ∼ 60 sec. at 3 K ). This behavior is explained as a result of occupation of a metastable anharmonic CTVE minima. An additional IR-pumping could transfer the occupation from the anharmonic CTVE state to the harmonic CTVE which is active for recombination luminescence. The temperature dependence of τ for the anharmonic CTVEs with metastable behavior shows that the relaxation time is controlled by resonance as well as by phonon-induced tunneling. © 2005 IOP Publishing Ltd. |
ISSN: | 17426588 | DOI: | 10.1088/1742-6596/21/1/028 | Externe URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-25444447961&doi=10.1088%2f1742-6596%2f21%2f1%2f028&partnerID=40&md5=9d85f5645f668105076555f0d01fd158 |
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