Molecular Structural and Environmental Origins of Charge Trapping and Their Effects on Operational Stability of Organic Field-Effect Transistors

Charge trapping in organic semiconductors (OSCs) has a significant influence on the performance and operational stability of organic electronic devices. Therefore, systematic and quantitative investigations on charge trapping behavior in OSCs have been of great interest in the field of organic electronics. In this talk, I will discuss our recent progress in understanding of charge transport and trapping phenomenon in OSCs and their effects on the operational stability of organic electronic devices. On the basis of our spectroscopic analyses on organic field-effect transistors (OFETs), we demonstrate molecular structural and environmental origins of charge trapping in OSCs. Effects of molecular order, molecular orientation, and backbone structure of polymer semiconductors are presented. The mechanisms of water-induced trap formation by residual water molecules within the OSC films are also proposed. Our detailed and sophisticated analyses on the charge trapping in OFETs would contribute to unveiling the charge trapping mechanisms in OSCs, and to realizing the robust and practical OFETs.