Fluorinated and methylated -benzodipyrrole-based acceptors suppressing charge recombination and minimizing energy loss in organic photovoltaics.

The elimination of the A' unit from -type Y6-derivatives has led to the development of a new class of -benzodipyrrole (-BDP)-based A-DBD-A-type NFAs. In this work, two new A-DBD-A-type NFAs, denoted as CFB and CMB, are designed and synthesized, where electron-withdrawing fluorine atoms and electron-donating methyl groups are substituted on the benzene ring of the -BDP moiety, respectively. CFB exhibits a blue-shifted absorption spectrum, stronger intermolecular interactions, shorter π-π stacking distances, and more ordered 3D intermolecular packing in the neat and blend films, enabling it to effectively suppress charge recombination in the PM6:CFB device showing a higher PCE of 16.

Sequence-controlled alternating block polychalcogenophenes: synthesis, structural characterization, molecular properties, and transistors for bromine detection.

Sequence-controlled polychalcogenophenes have attracted much interest in terms of synthesis, structure and function in polymer science. For the first time, we developed a new class of alternating block conjugated copolymers denoted as poly(-AB)--(-AC) where both blocks are constituted by an alternating copolymer. 3-Hexylthiophene (S), 3-hexylselenophene (Se) and 3-hexyltellurophene (Te) are used as A, B and C units to assemble three sequence-controlled polychalcogenophenes P(SSe)(STe), P(SSe)(SeTe) and P(STe)(SeTe) which are prepared by adding two different Grignard monomers in sequence to carry out Ni(dppp)Cl-catalyzed Kumada polymerization.