π‐Extented Conjugated Polymers Entailing Pechmann Dye Moieties for Solution‐Processed Ambipolar Organic Semiconductors

Abstract

AbstractIn this paper, we report the design, synthesis and semiconducting behavior of two conjugated D‐A polymers BPDDTE and BPDBDTE which entail BPD, a Pechmann dye framework, as electron accepting moieties and (E)‐1,2‐di(thiophen‐2‐yl)ethane with and without alkyl chains as electron donating moieties. They both show very narrow bandgaps below 1.3 eV. Based on the characterization of the field‐effect transistors, thin film of BPDDT exhibits ambipolar semiconducting properties with hole and electron mobilities reaching 0.245 and 0.095 cm2·V????????????1·s−1, respectively, after thermal annealing. Similarly, BPDBDTE with more alkylchains shows ambipolar semiconducting behavior with hole mobility and electron mobilities reaching 0.109 and 0.081 cm2·V−1·s−1. Furthermore, BPDBDTE shows good solubilities in several common organic solvents and thus is easily solution‐processible. Thus, BPDBDTE is potentially processible with inkjet printing and roll‐to‐roll printing techniques.