Direct observation of charge separation in an organic light harvesting system by femtosecond time-resolved XPS.

ABSTRACT: The ultrafast dynamics of photon-to-charge conversion in an organic light-harvesting system is studied by femtosecond time-resolved X-ray photoemission spectroscopy (TR-XPS) at the free-electron laser FLASH. This novel experimental technique provides site-specific information about charge separation and enables the monitoring of free charge carrier generation dynamics on their natural timescale, here applied to the model donor-acceptor system CuPc:C₆₀. A previously unobserved channel for exciton dissociation into mobile charge carriers is identified, providing the first direct, real-time characterization of the timescale and efficiency of charge generation from low-energy charge-transfer states in an organic heterojunction. The findings give strong support to the emerging realiz

SUBMITTER: Roth F 

PROVIDER: S-EPMC7895929 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature