Synthesis and properties of azothiazole based π-conjugated polymers

Abstract

In this study, azothiazole, namely (E)-1,2-di(thiazol-2-yl)diazene, is used as a building block to construct π-conjugated polymer semiconductors. It is found that azothiazole is a strong electron withdrawing moiety and suitable as an electron acceptor unit to form donor–acceptor (D–A) polymers. Two D–A polymers comprising azothiazole as the acceptor and bithiophene and thieno[3,2-b]thiophene as the donors, respectively, are synthesized. These polymers have small band gaps (∼1.2–1.3 eV) and low energy levels. When being used as channel semiconductors in organic thin film transistors, they show promising p-channel field effect transistor performance with hole mobility as high as 0.019 cm² V⁻¹ s⁻¹.