Abstract: Soluble polythiophene (PT) derivatives and fullerenes (mainly C₆₀) are the donor and acceptor materials respectively well-used in the photosensitive blend layer of the polymer solar cells. Aggregation of the fullerenes and phase separation of the donor and acceptor materials in the blend layer influence the power conversion efficiency (PCE) of the devices. So this paper synthesizes thiophene oligomers step by step through Suzuki coupling reaction and connects the thiophene oligomers with the fullerene acceptor together by covalent bond to solve the phase separation problem. By this way,the copolymer(Th₂C₆₀ Th₄C₆₀ ) can phase separation in molecular level. The molecular structures were determined by H-NMR and MALDI-Toff techniques. Cyclic voltammetry shows there’s no interaction between thiophene and C₆₀ at ground state.

Key words: thiophene oligomers, C₆₀, solar cell