1 research outputs found
Medium-Bandgap Conjugated Polymers Containing Fused Dithienobenzochalcogenadiazoles: Chalcogen Atom Effects on Organic Photovoltaics
We
designed, synthesized, and characterized a series of three medium-bandgap
conjugated polymers (PBDTfDTBO, PBDTfDTBT, and PBDTfDTBS)
consisting of fused dithienobenzochalcogenadiazole (fDTBX)-based
weak electron-deficient and planar building blocks, which possess
bandgaps of ∼2.01 eV. The fDTBX-based medium-bandgap polymers
exhibit deep-lying HOMO levels (∼5.51 eV), which is beneficial
for use in multijunction polymer solar cell applications. The resulting
polymers with chalcogen atomic substitutions revealed that the difference
in the electron negativity and atomic size of heavy atoms highly affects
an intrinsic property, morphological feature, and photovoltaic property
in polymer solar cells. The polymer solar cells based on sulfur-substituted
medium-bandgap polymer showed power conversion efficiencies above
6% when blended with [6,6]-phenyl-C<sub>71</sub>-butyric acid methyl
ester in a typical bulk-heterojunction single cell. These results
suggest that the fDTBX-based medium-bandgap polymer is a promising
alternative material for P3HT in tandem polymer solar cells for achieving
high efficiency