Highly Efficient Inverted D:A 1 :A 2 Ternary Blend Organic Photovoltaics Combining a Ladder-type Non-Fullerene Acceptor and a Fullerene Acceptor.

A formylated benzodi(cyclopentadithiophene) (BDCPDT) ladder-type structure with forced coplanarity is coupled with two 1,1-dicyanomethylene-3-indanone (IC) moieties via olefination to form a non-fullerene acceptor, BDCPDT-IC. The BDCPDT-IC, as an acceptor (A1 ) with broad light-absorbing ability and excellent solution processability, is combined with a second PC71 BM acceptor (A2 ) and a medium band gap polymer, PBDB-T, as the donor (D) to form a ternary blend with gradient HOMO/LUMO energy alignments and panchromatic absorption. The device with the inverted architecture using the D:A1 :A2 ternary blend has achieved a highest efficiency of 9.79% with a superior Jsc of 16.84 mA cm-2 .