Vacuum-processed small molecule solar cells based on terminal acceptor-substituted low-band gap oligothiophenes

Novel A-D-A type oligothiophenes incorporating benzothiadiazole (BTDA) and thiadiazolopyridine (TDAPy) as terminal acceptor groups have been developed for small molecule organic solar cells (SMSC). In vacuum-processed planar heterojunction solar cells the TDAPy-based oligomer showed a power conversion efficiency of 3.15% and a high fill factor of 0.67.