Design of donor–acceptor copolymers for organic photovoltaic materials: a computational study

80 different push–pull type organic chromophores which possess Donor–Acceptor (D–A) and Donor–Thiophene–Donor–Thiophene (D–T–A–T) structures have been systematically investigated by means of density functional theory (DFT) and time-dependent DFT (TD-DFT) at the B3LYP/6-311G* level.