Vertical Phase Separation to Regulate the Structural Morphology of Organic Semiconductors and Its Applications

Organic semiconductors (OSCs) are expected to play an important role in next-generation electronics due to their solution processability, etc. However, conjugated polymer films processed in solution usually have the problems of low crystallinity and carriers are easily trapped by semiconductor/dielectric layer interface traps, while solution processed small molecule OSCs films have poor integrity, both of which will lead to the damage of electrical properties. The vertical phase separation (VPS) of blend films of OSCs and insulating polymers (IPs) can solve these problems, improve the solution processability of small molecule OSCs, enhance the crystallinity of conjugated polymers, reduce interface traps, and significantly improve the performance of organic field-effect transistor (OFET). This review highlights key factors influencing the structural morphology of OSC/IP blend VPS films, and summarizes their applications in OFETs. Finally, challenges and opportunities for the preparation of multifunctional OFETs from OSC/IP blends are summarized and discussed.