Doping effect on photoabsorption and charge-separation dynamics in light-harvesting organic molecule

Satoshi Ohmura, Kenji Tsuruta, Fuyuki Shimojo, Aiichiro Nakano

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Using ab-initio theoretical methods, we demonstrate possible enhancement of photo-conversion efficiency of an organic solar cell via intentional doping in molecular graphene-fullerene heterojunction [the hexabenzocoronene (HBC)-triethylene glycol (TEG)-C60 molecule]. Photoabsorption analysis indicates oxygen substitution into HBC leads to an extension of the spectra up to an infrared regime. A quantum-mechanical molecular dynamics simulation incorporating nonadiabatic electronic transitions reveals that a dissociated charge state (D+ and A-) in the O-doped system is more stable than the pristine case due to the presence of an effective barrier by the TEG HOMO/LUMO level. We also find that oxygen doping in HBC enhances the intermolecular carrier mobility after charge separation. On the other hand, the pristine molecule undergoes rapid recombination between donor and acceptor charges at the interface. These analyses suggest that the graphene oxidation opens a new window in the application of organic super-molecules to solar cells.

Original languageEnglish
Article number015305
JournalAIP Advances
Issue number1
Publication statusPublished - Jan 1 2016

ASJC Scopus subject areas

  • General Physics and Astronomy


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