Organic donor-σ-acceptor molecules based-on 5,5′-(9,10-bis((4-hexylphenyl)ethynyl)anthracene-2,6-diyl)bis(ethyne-2,1-diyl)bis(2-hexylthiophene)

New donor-σ-acceptor (D-σ-A) molecules of (HAT)–n(PCBM) (where n = 1 and 2; PCBM refers to [6,6]-phenyl C61-butyric acid methyl ester and HAT refers to 5,5′-(9,10-bis((4-hexylphenyl)ethynyl)anthracene-2,6-diyl)bis(ethyne-2,1-diyl)bis(2-hexylthiophene)) were successfully synthesized for studying the intermolecular association behavior and their possible applications of these molecules to photovoltaic (PV) devices. In PV devices, (HAT)–n(PCBM) gave a reasonably high power conversion efficiency (PCE) of 0.18–0.44% with an open circuit voltage (Voc) ranging from 0.42 to 0.51 V without adding extra amount of PCBM.

► New organic donor-σ-acceptor molecules have been synthesized.
► (HAT)–2(PCBM) gave a PCE of 0.18% in photovoltaic cells.
► (HAT)–1(PCBM) gave a high PCE of 0.44%.
► The devices were fabricated without adding PCBM.