Design and development of dithienopyrrolobenzothiadiazole‐isoindigo based conjugated polymers and their hole mobilities

Abstract π‐Extended dithienopyrrolobenzothiadiazole‐isoindigo‐based conjugated polymers were synthesized and well characterized by using various analysis techniques like infrared (IR), 1 H NMR, UV–Visible spectroscopy, thermogravimetric analysis, cyclic voltammetry analysis, and gel permeation chromatography. The bandgap of synthesized polymers, P‐1 , P‐2 , and P‐3 , were determined to be 1.95, 1.91, and 1.93 eV, respectively. These polymers exhibited robust thermal stability up to 290°C. The highest occupied molecular orbital energy levels were below −5.0 eV for all polymers, while the lowest unoccupied molecular orbital energy levels ranged from −3.5 to −3.3 eV. The measured space charge limited current hole mobilities for polymers, P‐1 , P‐2 , and P‐3 , were 1.02 ± 0.47 × 10 −1 , 1.17 ± 0.47 × 10 −1 , and 2.51 ± 0 0.47 × 10 −2 cm 2 V −1 s −1 , respectively.