A comparison of para, meta, and ortho-carborane centred non-fullerene acceptors for organic solar cells
Anies, Filip; Furlan, Francesco; Qiao, Zhuoran; Pirela, Valentina; Bidwell, Matthew; Rimmele, Martina; Martin, Jaime; Gasparini, Nicola; Heeney, Martin
JOURNAL OF MATERIALS CHEMISTRY C
2023
We report the first examples of carborane-containing non-fullerene acceptors (NFAs), and their use in organic photovoltaic (OPV) devices. NFAs employing an A–D–A′–D–A type design centred around a central electron withdrawing carborane unit (A′), using either para, meta, or ortho-carborane isomers are reported. We demonstrate that the nature of the isomer has a major impact on device performance, despite minor differences in optoelectronic and morphological properties, with the use of ortho-carborane resulting in the highest device efficiencies. We further show that end-group fluorination is an efficient strategy to modulate energy levels and improve device performance of such NFAs.