Bay-annulated indigo based near-infrared sensitive polymer for organic solar cells.

ABSTRACT A new conjugated polymer (PBAIIDTT) based on bay-annulated indigo and indacenodithieno[3,2- b]thiophene was designed, synthesized, and characterized. PBAIIDTT shows strong absorption in 400-500 and 600-800 nm, and its HOMO and LUMO energy levels are −5.45 eV and −3.65 eV, respectively. In organic field-effect transistors, the polymer exhibits a relatively high hole mobility of 0.39 cm² V⁻¹ s⁻¹. PBAIIDTT was added to poly(3-hexylthiophene) (P3HT) and phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM) based organic solar cells. Ternary blend solar cells with 10% PBAIIDTT show an increased short circuit current density due to the broadened photocurrent generated in the near-infrared region, and a power conversion efficiency of 3.78%, which is higher than that of the P3HT:PC₆₁BM binary control devices (3.33%). © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 213-220 [ABSTRACT FROM AUTHOR]