Non‐Fullerene Acceptors with an Extended π‐Conjugated Core: Third Components in Ternary Blends for High‐Efficiency, Post‐Treatment‐Free Organic Solar Cells

The synthesis of four non-fullerene acceptors (NFAs) with a “A–π–D–π–A” structure, in which the electron-donating core is extended, was achieved. molecules differed by nature solubilizing groups on π-spacer and/or presence fluorine atoms peripheral electron-accepting units. optoelectronic properties were characterized solution, thin film, and photovoltaic devices. had minor influence but affected organization solid state. On other hand, influenced optoelectronics increased photo-stability films. Compared to reference ITIC, extended showed wider absorption across visible range higher lowest unoccupied molecular orbital energy levels. performances NFAs assessed binary blends using PM6 (PBDB-T-2F) as donating polymer ternary ITIC-4F. Solar cells (active area 0.27 cm2) power conversion efficiencies up 11.1 % when processed from non-halogenated solvents, without any thermal post-treatment or use halogenated additives, making this process compatible industrial requirements.