New n-Type Solution Processable All Conjugated Polymer Network: Synthesis, Optoelectronic Characterization, and Application in Organic Solar Cells

Abstract

The efficient synthesis of a new solution-processable n-type conjugated polymer network (PNT1) is reported through palladium-catalyzed Stille cross-coupling reaction conditions following the A₃ + B₂ synthetic approach. A benzo[1,2-b:3,4-b':5,6-b″]trithiophene derivative is used as the A₃ knot and an alkyl functionalized naphthalenediimide is utilized as the B₂ linker. The thermal, optical, and electrochemical properties are examined in detail, showing high thermal stability, absorbance in the visible part of the solar spectrum, and reversible reduction characteristics similar to those of the fullerene derivative [6,6]-phenyl-C₇₁ -butyric acid methyl ester (PC₇₁ BM). PNT1 is employed as the electron acceptor in solution-processed bulk heterojunction organic solar cells, demonstrating the potential of this new type of materials for optoelectronic applications.

Keywords: conjugated polymers; donor-acceptor; low bandgap; near infrared; organic photovoltaics.