X-ray induced ultrafast charge transfer in thiophene-based conjugated polymers controlled by core-hole clock spectroscopy

We explore ultrafast charge transfer (CT) resonantly induced by hard X-ray radiation in organic thiophene-based polymers at the sulfur K-edge. A combination of core-hole clock spectroscopy with real-time propagation time-dependent density functional theory simulations gives an insight into the electron dynamics underlying the CT process. Our method provides control over CT by a selective excitation of a specific resonance in the sulfur atom with monochromatic X-ray radiation. Our combined experimental and theoretical investigation establishes that the dominant mechanism of CT in polymer powders and films consists of electron delocalisation along the polymer chain occurring on the low-femtosecond time scale. Ultrafast charge transfer along the polymer chains is triggered by a selective resonant core-excitation of the sulfur atom in P3HT films and powders. Our approach opens perspectives for studies on intra-molecular conductivity in organic molecules.

Automated summary

This article investigates ultrafast charge transfer induced by hard X-ray radiation in organic thiophene-based polymers. By combining experimental and theoretical methods, it is found that electron resonance along the polymer chains is the dominant mechanism of charge transfer. The study provides a new perspective for studying intra-molecular conductivity in organic molecules.