Noncovalent interaction enables planar and efficient propeller-like perylene diimide acceptors for polymer solar cells

Abstract

The development of non-fullerene small molecule acceptors enabled fast increasing top power conversion efficiency of polymer solar cells (PSCs). Perylene diimide (PDI) derivatives are among the most promising non-fullerene small molecule acceptors for their relatively straightforward accessible PDI chromophores readily deliver high electron mobility and intensive photon absorption in visible range. In this work, we demonstrated noncovalent interaction as a third strategy of connecting the PDI arms to the center core of propeller-like PDI derivatives other than flexible and all fused linkages through designing and synthesizing two novel PDI derivatives. Thiophene-annulated PDI arms were connected to a small electron withdrawing 1,3,5-triazine center core where N⋯S noncovalent conformational locks restricted the distortion of molecules. Fine tuning of the aggregation tendency of the PDI derivative by introducing N-annulation at the outer bay position of each PDI arms which achieved an outstanding power conversion efficiency reaching 10.52%, which is one of the top PCEs of PDI-based PSCs.