Development of Non-Fullerene Acceptors with π-Extended Central Unit for Organic Photovoltaic Devices

Abstract

Over the past decade, organic photovoltaics (OPVs) have improved significantly, largely due to a new type of component called non-fullerene acceptors (NFAs) with acceptor-donor-acceptor (A-D-A) type structures. In this study, we created three different NFAs, all of which have an anthracene-fused nonacyclic D core (ATTICs). Despite having the same end A groups and side chains, these three ATTICs exhibited different behaviors due to the variations in the nonacyclic D cores, i.e., the positions and carbon numbers of non-aromatic rings fused to anthracene. One of the ATTICs did not dissolve well enough to be used in an OPV. However, when we used the other two NFAs to fabricate the OPVs with a conjugated polymer donor J71, they exhibited power conversion efficiencies of 7.1% and 1.8%. This shows that even small changes to the design of the NFAs can have a large impact on the photovoltaic performance.