Push-pull organic semiconductors comprising of bis-dimethylfluorenyl amino benzo[b]thiophene donor and various acceptors for solution processed small molecule organic solar cells

New efficient push-pull organic semiconductors comprising of on the N,N-(6-bis(9,9-dimethyl-9H-fluoren-2-yl)amino-benzo[b]thiophen (bisDMFABT) donor and the various acceptors such as NO2, DCBP, and TCF, which were linked with thiophene or vinyl thiophene π-conjugation bridges, were synthesized, and their photovoltaic characteristics were investigated in solution processed small molecule organic solar cells (SMOSCs). The intramolecular charge transfers of these materials were effectively appeared in between bisDMFABT donor and acceptors, depending on the electron-withdrawing strength of acceptors. The organic semiconductor having DCBF acceptor exhibited the best power conversion efficiency of 3.22% with short circuit current of 9.64 mA/cm2, fill fator of 0.42, and open circuit voltage of 0.80 V in SMOSC devices with TiOx thin layer.