Towards high-efficiency non-fullerene organic solar cells: Matching small molecule/polymer donor/acceptor

Abstract Two low band-gap donors, small molecule p-DTS(FBTTh 2 ) 2 (S D ) and polymer PBDTTT-C-T (P D ), and two perylene diimide acceptors, small molecule PDI-2DTT (S A ) and polymer PPDIDTT (P A ), were used to fabricate non-fullerene organic solar cells. The effects of four donor/acceptor combinations, P D /P A , P D /S A , S D /S A and S D /P A , on the morphology, charge transfer, charge transport and photovoltaic performance were investigated. Power conversion efficiencies (PCEs) of P D /P A , P D /S A , S D /S A and S D /P A were 3.04%, 0.28%, 2.52% and 0.29%, respectively. The P D /P A blend and S D /S A blend exhibited relatively uniform and continuous morphology, efficient photoinduced charge transfer, high mobility and balanced charge transport relative to P D /S A and S D /P A blends, leading to much higher PCEs.