Design, synthesis and properties of a new near-infrared small molecule acceptor for organic photodetector

Recently, organic photodetectors (OPDs) have occupied a crucial position in the photoelectric industry due to their low cost and convenient production. For its potential applications in near-infrared (NIR) wavelengths, NIR-OPDs with high responsivity and detectivity have attracted a lot of research interest. In this manuscript, we designed and synthesized a new n-type semiconductor, TPBT-OR, by introducing alkoxythiophene into Y5. TPBT-OR exhibits a small optical bandgap of 1.20 eV and red-shifted absorption peaks of 882 nm in film. Using P3HT as a donor and without much additional treatment in device, broad spectra response over 1011 Jones (cm Hz1/2 W−1) can be achieved in the wavelength of 320 nm–1000 nm with the maximum responsivity of 0.084 A W−1 and detectivity of 7.87 × 1011 Jones at around 850 nm. Thus, the new TPBT-OR molecule is a promising non-fullerene acceptor in near-ultraviolet to near-infrared detection.