Recent advances in rylene diimide polymer acceptors for all-polymer solar cells

In recent years, a large library of n-type polymers have been developed and widely used as acceptor materials to replace fullerene derivatives in polymer solar cells (PSCs), stimulating the rapid expansion of research on so-called all-polymer solar cells (aPSCs). In particular, rylene diimide-based n-type polymer acceptors have attracted broad research interest due to their high electron mobility, suitable energy levels, and strong light-harvesting ability in the visible region. Among various polymer acceptors, rylene diimide-based polymers presented best performances when served as the acceptor materials in aPSCs. Typically, a record power conversion efficiency (PCE) of 7.7% was very recently achieved from an aPSC with a rylene diimide polymer derivative as the acceptor component. In this review, we highlight recent progress of n-type polymers originated from two significant classes of rylene diimide units, namely naphthalene diimide (NDI) and perylene diimide (PDI), as well as their derivatives for aPSC applications. (C) 2015 Science Press and Dalian Institute of Chemical Physics. All rights reserved.