Can, AyseChoi, Gi-SeokOzdemir, ResulPark, SoyoonPark, Jin SuLee, YongchulDeneme, IbrahimMutlugun, EvrenKim, ChoongikKim, Bumjoon J.Usta, Hakan2023-03-022023-03-0220222637-6105WOS:000797863900046https://doi.org/10.1021/acsapm.1c01856?urlappend=%3Fref%3DPDF&jav=VoR&rel=cite-ashttps://hdl.handle.net/20.500.12573/1489The realization of π-deficient acceptors and their donor− acceptor copolymers has become a key research focus for the realization of versatile organic optoelectronic materials and devices. Herein, we demonstrate the theoretical design, synthesis, and physicochemical/ optoelectronic characterization of two meso-π-extended/deficient BODIPY building blocks (2OD−T2BDY and 2OD−TTzBDY) and a library of donor−acceptor copolymers with low band gap (Eg = 1.30−1.35 eV) based on these building blocks. These building blocks, to the best of our knowledge, are the first examples of BODIPYs with meso-π-extension. A library of BODIPY building blocks with varied meso units/substituents is studied to reveal the meso effects on the semiconducting BODIPY’s optoelectronic properties. The building blocks showed favorable πacceptor electronic/structural properties with meso-π-delocalized and stabilized LUMOs (ca. −3.6 eV) and large ground-state dipole moments of 4.9−5.5 D. Consistent with the theoretical/experimental π-electronic structures, all copolymers functioned as p-type semiconductors in field-effect transistors and as donor materials in the bulk heterojunction organic photovoltaics. Power conversion efficiencies of up to 4.4% with a short-circuit current of 12.07 mA cm−2 were achieved. This study demonstrates a unique meso-πextension strategy to realize BODIPYs with favorable π-acceptor properties, and our findings could open up future materials design avenues in various organic optoelectronic applications.enginfo:eu-repo/semantics/closedAccessconjugated polymersBODIPYorganic solar cellsorganic semiconductorsLUMOarticle4319912005