An important step in oxide photochemistry, the loading of electrons into shallow trap states, was studied using infrared (IR) spectroscopy on both, rutile TiO2 powders and single-crystal, r-TiO2 (110) oriented samples. After UV-irradiation or n-doping by exposure to H-atoms broad IR absorption lines are observed for the powders at around 940â€... cm-1. For the single crystal substrates, the IR absorption bands arising from an excitation of the trapped electrons into higher-lying final states show additional features not observed in previous work. On the basis of our new, high-resolution data and theoretical studies on the polaron binding energy in rutile we propose that the trap states correspond to polarons and are thus intrinsic in nature. We assign the final states probed by the IR-experiments to hydrogenic states within the polaron potential. Implications of these observations for photochemistry on oxides will be briefly discussed.

Sezen, H., Buchholz, M., Nefedov, A., Natzeck, C., Heissler, S., DI VALENTIN, C., et al. (2014). Probing electrons in TiO2 polaronic trap states by IR-absorption: Evidence for the existence of hydrogenic states. SCIENTIFIC REPORTS, 4 [10.1038/srep03808].

Probing electrons in TiO2 polaronic trap states by IR-absorption: Evidence for the existence of hydrogenic states

DI VALENTIN, CRISTIANA
Penultimo
;
2014

Abstract

An important step in oxide photochemistry, the loading of electrons into shallow trap states, was studied using infrared (IR) spectroscopy on both, rutile TiO2 powders and single-crystal, r-TiO2 (110) oriented samples. After UV-irradiation or n-doping by exposure to H-atoms broad IR absorption lines are observed for the powders at around 940â€... cm-1. For the single crystal substrates, the IR absorption bands arising from an excitation of the trapped electrons into higher-lying final states show additional features not observed in previous work. On the basis of our new, high-resolution data and theoretical studies on the polaron binding energy in rutile we propose that the trap states correspond to polarons and are thus intrinsic in nature. We assign the final states probed by the IR-experiments to hydrogenic states within the polaron potential. Implications of these observations for photochemistry on oxides will be briefly discussed.
Articolo in rivista - Articolo scientifico
Multidisciplinary
English
2014
4
03808
none
Sezen, H., Buchholz, M., Nefedov, A., Natzeck, C., Heissler, S., DI VALENTIN, C., et al. (2014). Probing electrons in TiO2 polaronic trap states by IR-absorption: Evidence for the existence of hydrogenic states. SCIENTIFIC REPORTS, 4 [10.1038/srep03808].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/82796
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