A General Approach toward Electron Deficient Triazole Units to Construct Conjugated Polymers for Solar Cells

Triazole based structural units have been widely used to construct conjugated polymers for optoelectronic applications; yet the design and synthesis of such units have been limited to just a few known examples. We report a general yet versatile synthetic approach toward a diverse set of triazole based conjugated molecules bearing various electron accepting abilities. The structural differences of as-synthesized three new triazole acceptors have a significant impact on the optoelectronic properties of conjugated polymers incorporating these triazoles. Bulk heterojunction solar cells based on one of these new polymers, PyCNTAZ, feature a high open circuit voltage of ∼1 V and a notable efficiency of 8.4% with an active layer thickness around 300 nm.