A promising non-fullerene acceptor for near-infrared organic photodetectors operating with low dark current and high response speed

Abstract

By tuning the band gaps of their active layer materials, organic photodetectors (OPDs) can display good responses in the near-infrared (NIR) region, making them useful for applications in biomedical imaging and optical communication. Nevertheless, NIR OPDs have tended to suffer from low specific detectivity (D*), due to a high dark current. In this study, we employed 3TT-FIC, a non-fullerene acceptor (NFA), to develop OPDs capable of operating with extremely low dark currents and high response speeds. After fine tuning the blend ratio of the donor (PM6) and acceptor (3TT-FIC), we obtained an OPD that operated at a low dark current (7.04 × 10-10 A/cm2) at –1 V with a high value of D* (2.6 × 1013 Jones) at the wavelength of 850 nm. We also describe the wider applicability of 3TT-FIC and its good potential for applications as an NFA in NIR OPDs.