High-performance fullerene-free polymer solar cells with 6.31% efficiency

A nonfullerene electron acceptor (IEIC) based on indaceno[1,2-b:5,6-b′]dithiophene and 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile was designed and synthesized, and fullerene-free polymer solar cells based on the IEIC acceptor showed power conversion efficiencies of up to 6.31%.