Isostructural, Deeper Highest Occupied Molecular Orbital Analogues of Poly(3-hexylthiophene) for High-Open Circuit Voltage Organic Solar Cells - Bronstein, H; Hurhangee, M; Fregoso, EC; Beatrup, D; Soon, YW; Huang, Z; Hadipour, A; Tuladhar, PS; Rossbauer, S; Sohn, E-H; Shoaee, S; Dimitrov, SD; et al. (CHEMISTRY OF MATERIALS, 2013)