In the past few decades

conjugated polymers

which are composed of repeating structural units and these subunits are typically connected by covalent chemical bonds

have attracted broad interest due to their unique optical

electrical and electrochemical properties.Due to the complexity of the conjugated polymers structure

such as chain segment

conformation and aggregation

it's difficult to synthesize defect-free polymers even use fine synthesis conditions.The low-energy emission from defects was enhanced in the film state compared to that in the corresponding solution

because the excited energy can transfer to defects effectively.The research of the structural defects in the conjugated polymers included the forming mechanism and control of defects

the analysis of defects density

the molecular structure and electronic structure of defects

etc.It's important to develop high quality materials.In this paper

we describe the progress of studies on defects in conjugated polymers.