Effects of Substituted Side-Chain Position on Donor–Acceptor

ABSTRACT: The optical properties and electrical properties of a series of low-band-gap conjugated copolymers, in which alkyl side chains were substituted at various positions, were investi-gated using donor–acceptor conjugated copolymers consisting of a cyclopentadithiophene derivative and dithienyl-benzothia-diazole. With substituted side chains, the intrinsic properties of the copolymers were significantly altered by perturbations of the intramolecular charge transfer. The absorption of poly[2