Ternary polymer solar cell based on two donors and one acceptor for improving morphology and power conversion efficiency

•Isoindigo-based copolymers were used to optimize the morphology in ternary blend system.•The nanophase morphology of blend film was characterization by AFM and TEM.•The ternary blend with two donors and one acceptor showed the highest PCE in Polymer solar cell.

We synthesized isoindigo-based two donor-acceptor (D-A) copolymers to optimize the morphology in ternary blend films with two p-type polymers and n-type phenyl-C61-butyric acid methyl ester (PC61BM). Compared to binary systems with a single copolymer and PC61BM, the ternary polymer solar cell with two copolymers and PC61BM showed highly enhanced power conversion efficiency of 5.13% with a high short circuit current of 13.23 mA cm−2. These results were supported by atomic force microscopy (AFM) and transmission electron microscopy (TEM) observations of the surface and internal morphology of the thin film, respectively.

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