Small Molecule/Polymer Blend Strategies for Solution-Processed Organic Thin Film Transistors

With the advancement of novel semiconductor materials and the continuous optimization of interface engineering, organic thin-film transistors (OTFTs) exhibit great potential applications in the field of flexible and wearable electronics. OTFTs based on vertical phase separation (VPS) structure (deriving from the blends of small molecules and polymers) demonstrate excellent characteristics such as high mobility, low subthreshold swing (SS), high uniformity, and both environmental and electrical stability. In this review, we summarize recent representative studies on high-performance OTFTs utilizing small molecule/polymer (insulating or semiconducting) blend films. Firstly, we discuss the phase separation of small molecule/polymer blends, including their mechanisms and characterization techniques. Subsequently, we explore the advantages and limitations of various solution processing techniques for fabricating small molecule/polymer blend films. We further summarize the strategies for controlling the microstructure of small molecule/polymer blend films and the comprehensive performance of these blends in OTFT applications. This review would promote the understanding and development of VPS structures in OTFTs. We believe that the small molecule/polymer blending strategy holds promising prospects in the development of advanced organic electronics.