IEICO-4F (or IOTIC-4F), CAS number 2089044-02-8, is a low band-gap and low energy-loss non-fullerene acceptor showing an A-D-A type structure with extra thiophenes as spacers between the acceptor and donor units. The structure has an electron-donating fused five-member-ring indaceno[1,2-b:5,6-b′]dithiophene (IDT) core, terminated by two electron-withdrawing units, 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (IC-2F). IEICO-4F extends into the near infrared (NIR) region with maximum absorption around 860 nm, 200 nm red-shifted compared to ITIC.
IEICO-4F or IEICO-4Cl can also be used in high performance panchromatic organic photodetectors (OPDS). OPD device based on P3HT:IEICO-4F:PC71BM exhibited a high detectivity (D*) of 1.35 × 1012 Jones at 805 nm.
By incorporating a small molecule donor BIT-4F-T, combining the merits of complementary absorption of the visible light region (400 - 600 nm) to the polymer donor PTB7-Th and non-fullerene acceptor IEICO-4F, PTB7-Th:BIT-4F-T:IEICO-4F ternary organic solar cells showed improved efficiencies, reaching up to a PCE of 14.0%.
Device structure: ITO/ZnO (~35 nm)/PTB7-Th:BIT-4F-T:IEICO-4F (0.9:0.1:1, 10% BIT-4F-T) and (~150 nm)/MoOx (~7 nm)/Ag (~100 nm)