New pi-Conjugated Polymers Containing 4H,4 ' H-[1,1 '-Bithieno[3,4-C]Pyrrole]-4,4 ',6,6 '(5H,5 ' H)-Tetraone (biTPD) Units and their Application to Thin-Film Transistors and Photovoltaic Cells

Abstract

We successfully synthesized new D-A copolymers that employ 1,10-bithienopyrrolodione (biTPD), thiophene, and selenophene-based donor monomeric units. Two polymers, PBTPDEBT and PBTPDEBS, exhibited high degrees of crystallinity and unique polymer chain arrangements on the substrate, which is attributed to their enhanced coplanarity and intermolecular interactions between the polymer chains. Among the thin-film transistor devices made of PBTPDEBT and PBTPDEBS, the annealed PBTPDEBS device displayed relatively high hole mobility, which was twice that of the PBTPDEBTbased device. In addition, an organic photovoltaic device based on a PBTPDEBS: PC71BM blend displayed the maximum power conversion efficiency of 3.85%. (C) 2015 Wiley Periodicals, Inc.