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Abstract: Three stable polyradicals with large π-conjugated planar phenalenyl (PLY) radical units as side chain were synthesized. Due to the different conjugated backbones and the interactions between main chains and side chains, these polyradicals and their corresponding precursor polymers presented diverse optical and electrical properties, which were confirmed by UV–vis, fluorescence and CV detections. Besides, they showed excellent solubility in common organic solvents and good stability in the air. Considering their special characteristics, we have fabricated photovoltaic (PV) devices using these polyradicals or polymers as donor material and PCBM as acceptor material. The significant PV performance improvement was observed using a radical-based active layer in the PV devices. [Copyright &y& Elsevier]

Abstract: Two low bandgap conjugated polymers containing vinylene unit on their main chains, poly(dithienosilole vinylene) derivatives P1 and P2, were synthesized by Pd-catalyzed Stille-coupling method. The two polymers show good solubility in common organic solvents, broad absorption bands from 500nm to 700nm and lower energy bandgap of 1.72eV for P1 and 1.77eV for P2. The electronic energy levels of the polymers were measured by electrochemical cyclic voltammetry. The HOMO and LUMO energy levels of P1 and P2 are at −5.03eV, −5.18eV and −3.39eV, −3.43eV, respectively. The polymers P1 and P2 containing dithienosilole units show lower HOMO and LUMO energy levels, in comparison with other poly(thienylene vinylene) derivatives. [Copyright &y& Elsevier]