Synthesis and photovoltaic performances of 2,5-dioctyloxy-1,4-phenylenevinylene and terthiophene copolymers with di(p-tolyl)phenylamine and oxadiazole side groups

Three novel conjugated polymers (P1, P2, and P3), comprised of 2,5-dioctyloxy-1,4-phenylenevinylene and terthiophene derivatives with/without di(p-tolyl)phenylamine (TPAV) and oxadiazole (OXD) side groups, have been synthesized via the Witting–Horner reaction. The effect of TPAV and OXD side groups on the optical, electrochemical and photovoltaic properties has been investigated. It is found that the introduction of TPAV and OXD side groups to the backbone of P2 and P3 exhibits broader and stronger absorption than that of P1 without TPAV and OXD side groups. Photovoltaic cells have been fabricated with the as-synthesized polymers as the donors and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor in a 1:4 weight ratio. The device based on P2 shows a maximum power conversion efficiency of 1.75% under simulated AM 1.5 G solar irradiation (100 mW/cm2).