Grain boundary engineering of organic semiconductor films in organic transistors

Abstract Organic field‐effect transistors (OFETs) show great application potential in organic electronic and optoelectronic fields due to their excellent mechanical flexibility, low cost, and solution processing. However, grain boundaries (GBs) disrupt the aggregation state of organic semiconductor (OSC) films and hinder electrical performance and stability, which limits the application of OFETs. Besides, the sensitive nature of GBs is widely used in sensing, but detailed descriptions of the GBs are scarce. This review aims to fill this knowledge gap. The role of GBs and their effect on the performance and stability of OFETs are analyzed, followed by a detailed summary of the characterization of GBs. Then, strategies for suppressing the negative effects of GBs and utilizing the sensitive nature of GBs for application are proposed. Finally, potential research directions for GBs in OFETs are discussed.