Synthesis and absorption properties of small-molecule acceptor based rich-electronic benzodiselenophene core with hybrid bromination and fluorination end-group

At present, dihalogenated 1, 1-dicyanomethylene-3-indanone (IC) have attracted widely attention as terminal unit. Here, our work designed and synthesized a new nonfullerene small molecule acceptor material BDSe-FBr, with simultaneously fluorinated brominated terminal. Due to that bromine atom has more electrons larger size, fluorine enhanced intermolecular π-π packing, BDSe-FBr present strong absorption abilities in solution film. It shows broad range of 600–800 nm 700– 900 nm, the maximum peak film 742 774 respectively, optical band gap is 1.40 eV. The results are beneficial for high JSC less energy loss these due packing. multiple interactions between heteroatom also improve charge transportation crystallinity. This A-D-A type molecules end-group provide an effective strategy photovoltaic performance acceptor. introduction atoms into group exhibits great prospects application OSCs.