Rational design of the S,N‐heteroacene‐based nonfullerene by introducing the fluorine atom for efficient high‐performance organic solar cells

Abstract

AbstractFluorination has been established as an effective structural modification strategy to influence properties and has attracted attention in organic solar cells. Here, we design and synthesize three fused‐ring electron acceptors based on ladder‐type pentacyclic heteroacenes as the electron‐rich unit and 1,1‐dicyanomethylene‐3‐indanones with 0–2 fluorine substituents as the electron‐deficient units. Among these three molecules, two fluorine substituents nonfullerene acceptor, DTP‐2F exhibit strong absorption with high extinction coefficients and deep HOMO and LUMO level as compared with DTP‐0F and DTP‐1F. Device studies show that fluorinated nonfullerene acceptors (NFAs) lead to reduced VOC but increased JSC and FF, and therefore, the ultimate influence to efficiency depends on the compensation of VOC loss and gains of JSC and FF. Furthermore, fluorination affect to film morphology and miscibility between donor and acceptor. The fluorination of NFAs is one of the best design method of the donor and acceptor materials for efficient high‐performance organic solar cell.