New wide band gap dithieno[3′,2′:5,6;2′′,3′′:7,8]naphtho[2,3-d]imidazole-9(10H)-one-containing polymers and ternary composites with fullerene and non-fullerene acceptors: mobility of charge carriers

Abstract

Four new donor–acceptor conjugated polymers based on the acceptor block 8,10-bis(2-octyldodecyl)-8H-dithieno[3′,2′:5,6;2′′,3′′:7,8]naphtho[2,3-d]imidazole-9(10H)-one and various donor moieties were synthesized. Binary and ternary composites comprising new polymers, PC71BM fullerene and non-fullerene acceptors based on indacenodithiophene, were developed. The mobility of electrons and holes in thin films of the ternary composites is balanced in contrast to that in binary composite films. This is explained by less aggregation in the ternary composite films and good matching of the frontier orbital energy levels of the composite components.