Isoindigo, a classical electron‐deficient unit for organic optoelectronic materials, has been widely used in organic field‐effect transistors (OFETs) and organic photovoltaic devices (OPVs). However, several intrinsic drawbacks, such as its non‐coplanarity and weak absorption in the visible‐light region, have hindered its further development. Recently, many optimized isoindigo derivatives have been successfully applied to OFETs and OPVs. This Focus Review discusses recent progress in the structural optimization of isoindigo‐based organic optoelectronic materials and provides meaningful guidelines for the design of high‐performance isoindigo derivatives for organic electronics.

Pyrazine-fused isoindigo (PzIIG) was designed and synthesized as a novel electron acceptor to construct two D-A conjugated polymers, PzIIG-BDT2TC8 and PzIIG-BTT2TC10. Both the polymers were successfully applied in polymer solar cells, and the PzIIG-BDT2TC8 based solar cell device exhibited a PCE of 5.26% with a high V over 1.0 V.