New Didecyloxyphenylene−Acceptor Alternating Conjugated Copolymers: Synthesis, Properties, and Optoelectronic Device Applications

Abstract

Seven donor−acceptor copolymers incorporating didecyloxyphenylene (DP) donor and the following acceptors—thieno[3,4-b]pyrazine (TP), 2,1,3-benzothiadiazole (BT), quinoxaline (Q), pyridine (Py), 2,3-dimethyl-5,7-dithien-2-yl-thieno[3,4-b]pyrazine (DTTP), 4,7-dithien-2-yl-2,1,3-benzothiadiazole (DTBT), and 2,3-dimethyl-5,7-dithien-2-yl-quinoxaline (DTQ)—were synthesized by Suzuki coupling polymerization. The effects of the acceptor strength and backbone planarity on the optical, electrochemical, field-effect charge transport, and photovoltaic properties of the donor−acceptor copolymers were investigated. The optical band gap (eV) of the copolymers showed the trend of DP/TP (1.47) < DP/BT (2.37) < DP/Py (2.76) < DP/Q (2.78) < DP/P (3.15). The DP/TP copolymer had a field-effect hole mobility of 1.89 × 10−3 cm2 V−1 s−1. The DP/DTBT and DP/DTQ copolymers showed hole mobilities of 1.92 × 10−4 and 2.10 × 10−3 cm2 V−1 s−1, respectively. The strong acceptor strength of TP and coplanar backbone in the DP/TP copolyme...