6533b872fe1ef96bd12d2f9a
RESEARCH PRODUCT
Regio(ir)regular naphthalenediimide- and perylenediimide-bithiophene copolymers: How MO localization controls the bandgap
Antonio FacchettiJohannes GierschnerBegoña Milián-medinaBegoña Milián-medinaZhihua ChenMichael Wykessubject
Absorption spectroscopyOrganic solar cellBand gapChemistry02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesAcceptor0104 chemical sciencesMaterials ChemistryCopolymerMolecular orbitalSinglet stateTriplet state0210 nano-technologydescription
Absorption spectra of regio(ir)regular naphthalenediimide (NDI)- and perylenediimide (PDI)-bithiophene (2T) donor/acceptor (D/A) copolymers are surprisingly similar despite cross-conjugation in the regioirregular structures. This result is traced back to largely localized frontier molecular orbitals (FMOs) as revealed by (time-dependent) DFT calculations. Interestingly, while the FMOs of the P(PDI-2T) copolymer are localized solely in the PDI units, they are predominantly localized in the respective D/A units of the P(NDI-2T) copolymer. The pronounced CT character of the lowest singlet state in P(NDI-2T) should give rise to a close lying CT triplet state, generating small singlet–triplet gaps; this property might be of significant importance for the future design of polymers for organic solar cells with reduced charge recombination rates.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-01-01 |