Utilizing Benzotriazole-Fused DAD-Type Heptacyclic Ring to Construct n-Type Polymer for All-Polymer Solar Cell Application

Polymerizing small-molecule acceptor is a valid method for combining the advantages of small molecule acceptors and polymer acceptors. Here, a weak electron-deficient unit, benzo[d] [1,2,3]-triazole (BTA) was fused to get the heptacyclic ring of dithienothiophen[3,2-b]-pyrrolobenzo[d][1,2,3]-triazole (TPBTA), which was utilized as DAD unit to synthesize a A'-DAD-A'-D' type polymer acceptor (named as A702). After being blended with classic p-type polymer PBDB-T, a high PCE of 11.84% with an open-circuit voltage (V-OC) of 0.9 V was achieved. Our results indicate the heptacyclic ring containing BTA unit can be regarded as an attractive option to build high-efficient PAs.

Automated summary

Polymerizing small-molecule acceptor with a weak electron-deficient unit, benzo[d] [1,2,3]-triazole, led to the synthesis of a high-efficient polymer acceptor A702, which achieved a high PCE of 11.84%. The heptacyclic ring containing BTA unit proved to be an attractive option for building efficient polymer acceptors.