prof. Dean Cvetko: Ultrafast Electron Transfer at Molecular Interfaces by Core-Hole Clock Spectroscopy
Povzetek:
Ultrafast Electron Transfer at Molecular Interfaces by Core-Hole Clock Spectroscopy
Prof. Dean Cvetko
Faculty for mathematics and physics, University of Ljubljana,
CNR-IOM Laboratorio Nazionale TASC @ Elettra synchrotron, Trieste, Italy
Understanding the interplay between molecular bonding and charge transfer effciency in heterojunctions is a key issue for molecular engineering and design of novel organic nanodevices. Experimentally, different channels for carrier transfer within molecular assemblies can be probed with resonant x-ray photoemission (RPES) by measuring the time of electron and/or hole delocalization from the specific site of creation. The detection of ultrafast charge delocalization may then reveal the orbital pathways for fast carrier transport and provide unique insight in the origin of the assembly’s conductive properties. The basics of core-hole-clock (CHC) experiments [1] and the models used to extract the timescale of the excited charge delocalization and the spatial distribution of molecular valence states will be briefly discussed. CHC measurements of fast electron dynamics in a few organic systems with p-p and donor-acceptor molecular coupling will be presented to demonstrate the essential coupling motifs for efficient transport in non-covalent molecular junctions [2].
References
[1] P.A.Bruhwiler et al., Review of Modern Physics,74, 703 (2002); A. Föhlisch et al., Nature, 436 , 373 (2005).
[2] G.Kladnik et al., The journal of physical chemistry.C, Nanomaterials and interfaces, 117, 16477, (2013), A.Batra et al., Nature communications, 3, 1086-1, (2012), T.Schiros et al., Advanced energy materials, 3, 894-902 (2013).
