Synthesis of a 4,8-dialkoxy-benzo[1,2-b:4,5-b′]difuran unit and its application in photovoltaic polymer

A new building block of benzo[1,2-b:4,5-b']difuran (BDF) was firstly designed and synthesized. The newly designed unit was applied for constructing a new photovoltaic low band gap polymer, PBDFDTBT, which exhibited promising power conversion efficiency of 5.0%.