Synthesis and characterizations of benzotriazole based donor–acceptor copolymers for organic photovoltaic applications

Donor–acceptor alternated conjugated copolymers based on benzotriazole acceptor units and electron-donating units such as fluorene, carbazole and silyl fluorene, were synthesized through palladium catalyzed Suzuki cross-coupling polymerization. NMR and elemental analyses were achieved to confirm the structure of each copolymer. Their thermal, photophysical and electrochemical properties are also reported. The photovoltaic characteristics of these polymers determined from bulk-heterojunction photovoltaic cells are discussed.