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

[Display omitted] ► Donor–acceptor alternated conjugated copolymers based on benzotriazole. ► Three polymers: fluorene, carbazole and silyl fluorene as electron-donating units. ► Synthesis via the palladium catalyzed Suzuki cross-coupling polymerization. ► Absorption and emission spectroscopies, electrochemistry, photovoltaic devices. ► Relationship between the structure and physical properties of the three polymers. 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.