Evidence for Two-Path Recombination of Photoinduced Small Polarons in ReducedLiNbO3
| Autor: | Mirco Imlau, C. Merschjann, D. Berben, Manfred Wöhlecke |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | Physical Review Letters. 96 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | The recombination of photoinduced free ${\mathrm{Nb}}_{\mathrm{Nb}}^{4+}$ and bound ${\mathrm{Nb}}_{\mathrm{Li}}^{4+}$ small polarons to ${\mathrm{Nb}}_{\mathrm{Li}}^{4+}\ensuremath{\mathbin:}{\mathrm{Nb}}_{\mathrm{Nb}}^{4+}$ bipolarons is investigated in nominally pure, reduced ${\mathrm{LiNbO}}_{3}$ single crystals by means of excited-state-absorption spectroscopy. We discovered a two-component decay of the light-induced absorption ${\ensuremath{\alpha}}_{\mathrm{li}}(t)$ for probe light at $\ensuremath{\lambda}=785\text{ }\text{ }\mathrm{nm}$ and moderate pump beam intensities (${I}_{\mathrm{p}}\ensuremath{\ll}670\text{ }\text{ }\mathrm{GW}/{\mathrm{m}}^{2}$). These experimental results give strong evidence for the existence of a two-path recombination of the photoinduced polarons. A corresponding model taking into account hopping charge transport and trapping is presented. |
| Databáze: | OpenAIRE |
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