Diketopyrrolopyrrole‐Dioxo‐Benzodithiophene‐Based Multifunctional Conjugated Polymers for Organic Field‐Effect Transistors and Perovskite Solar Cells

Abstract

While dual‐acceptor‐type conjugated polymers have witnessed a great success in organic field‐effect transistors (OFETs), their potential multifunctionality in other optoelectronic devices has been overlooked. Herein, three conjugated polymers (DPPF‐BDD, DPPT‐BDD, and DPPSe‐BDD) comprising furan/thiophene/selenophene‐flanked diketopyrrolopyrrole (DPP) and dioxo‐benzodithiophene (BDD) as repeating units are designed, synthesized, and characterized. Modulating the chalcogen on DPP flank shows an impact on dual‐acceptor polymer optoelectronic properties. Subsequently, the potential of these polymers in both OFETs and perovskite solar cells (PSCs) either as semiconductors or as passivation materials, respectively, is investigated. Interestingly, DPPF‐BDD, DPPT‐BDD, and DPPSe‐BDD show ambipolar behavior in vacuum with hole (μh) and electron (μe) mobilities of 0.0263/0.0223, 0.0187/0.0123, and 0.0070/0.0051 cm2 V−1 s−1, respectively. Upon doping tetrabutylammonium iodide into DPPF‐BDD, DPPT‐BDD, and DPPSe‐BDD polymers, the respective OFETs show relatively higher μh and μe (0.0389/0.0503; 0.0289/0.0259; 0.0058/0.0156 cm2 V−1 s−1) than the undoped polymer OFETs. Furthermore, DPPF‐BDD‐, DPPT‐BDD‐, and DPPSe‐BDD‐incorporated (in the antisolvent treatment and PCBM electron transport layer) PSCs display maximum power conversion efficiency of 23.48%, 22.85%, and 23.35%, respectively, surpassing the control device (22.83%), which is benefited from the perovskite surface passivation and the charge extraction improvement. Overall, a new class of multifunctional DPP‐based dual‐acceptor‐type polymers that are highly compatible with OFETs and high‐performance PSCs is presented.