High Performance All-Polymer Photodetector Comprising a Donor–Acceptor–Acceptor Structured Indacenodithiophene–Bithieno[3,4- c ]Pyrroletetrone Copolymer

International audienceThe synthesis of an acceptor polymer PIDT-2TPD, comprising indacenodithiophene (IDT) as theelectron-rich unit and an interconnected bithieno[3,4-c]-pyrrole-4,4′,6,6′-tetrone (2TPD) as the electron-deficientunit, and its application for all-polymer photodetectors isreported. The optical, electrochemical, charge transport, anddevice properties of a blend of poly(3-hexylthiophene) andPIDT-2TPD are studied. The blend shows strong complementaryabsorption and balanced electron and hole mobility,which are desired properties for a photoactive layer. Thedevice exhibits dark current density in the order of 10exp−5 mA/cm2, external quantum efficiency broadly above 30%, and nearly planar detectivity over the entire visible spectral range(maximum of 1.1 × 10exp12 Jones at 610 nm) under −5 V bias. These results indicate that PIDT-2TPD is a highly functional newtype of acceptor and further motivate the use of 2TPD as a building block for other n-type materials