We synthesized and characterized three new amorphous dithienylbenzothiadiazole (TBT)-triphenylamine (TPA) polymers for application in bulk-heterojunction (BHJ) organic photovoltaic (OPV) cells. Poly(3HTBT-TPA) has hexyl side chains on the thienyl groups (pointing toward the benzothiadiazole (BTD) unit), and poly(4HTBT-TPA) has hexyl side chains on the thienyl groups (pointing outward from the BTD unit). The incident photon to current conversion efficiencies (IPCEs) in the region from 550 to 650 nm for the OPV cells prepared using poly(4HTBT-TPA) were higher than those for the OPV cells prepared using poly(3HTBT-TPA) because the absorption spectrum for the poly(4HTBT-TPA) has a slightly red-shifted absorption edge. We also demonstrated that the poly(4HTBT-TPA)-based OPV performance is independent of the fabrication process, so using an amorphous film to fabricate BHJ OPV cells offers great advantages over using a polycrystalline film in terms of the high reproducibility of the OPV performance. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 25362544