We investigate by first-principles simulations the resonant electron-transfer lifetime from the excited state of an organic adsorbate to a semiconductor surface, namely, isonicotinic acid on rutile TiO2(110). The molecule–substrate interaction is described using density functional theory, while the effect of a truly semi-infinite substrate is taken into account by Green’s function techniques. Excitonic effects due to the presence of core-excited atoms in the molecule are shown to be instrumental to understand the electron-transfer times measured using the so-called core-hole-clock technique. In particular, for the isonicotinic acid on TiO2(110), we find that the charge injection from the LUMO is quenched, since this state lies within the substrate band gap. We compute the resonant charge-transfer times from LUMO+1 and LUMO+2, and systematically investigate the dependence of the elastic lifetimes of these states on the alignment among adsorbate and substrate states.

Resonant lifetime of core-excited organic adsorbates from first principles / G. Fratesi, C. Motta, M.I. Trioni, G.P. Brivio, D. Sánchez-Portal. - In: JOURNAL OF PHYSICAL CHEMISTRY. C. - ISSN 1932-7447. - 118:17(2014 Apr 01), pp. 8775-8782. [10.1021/jp500520k]

Resonant lifetime of core-excited organic adsorbates from first principles

G. Fratesi
Primo
;
M.I. Trioni;
2014-04-01

Abstract

We investigate by first-principles simulations the resonant electron-transfer lifetime from the excited state of an organic adsorbate to a semiconductor surface, namely, isonicotinic acid on rutile TiO2(110). The molecule–substrate interaction is described using density functional theory, while the effect of a truly semi-infinite substrate is taken into account by Green’s function techniques. Excitonic effects due to the presence of core-excited atoms in the molecule are shown to be instrumental to understand the electron-transfer times measured using the so-called core-hole-clock technique. In particular, for the isonicotinic acid on TiO2(110), we find that the charge injection from the LUMO is quenched, since this state lies within the substrate band gap. We compute the resonant charge-transfer times from LUMO+1 and LUMO+2, and systematically investigate the dependence of the elastic lifetimes of these states on the alignment among adsorbate and substrate states.
Settore FIS/03 - Fisica della Materia
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/235528
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