A Dry-Transfer Method for Molecular Monolayer Crystals toward Flexible High-Performance Organic Field-Effect Transistors

The single crystals of organic semiconductor crystals (SC-OSCs) have displayed great potential in organic field-effect transistors (OFETs), given the high mobility brought by the long-range ordering and the absence of structural defects in SC-OSCs. Benefiting from their intrinsic flexibility and thinnest possible thickness, molecular monolayer crystals (MMCs) are considered to be one of the optimum candidates as the active layer in flexible OFETs. In this work, a new dry-transfer method via an in situ vapor-deposited parylene film on MMCs was developed for fabricating flexible OFETs. The transferred MMCs retained an atomically flat surface and long-range ordering and exhibited a conformal and residue-free interface with the dielectric layer, thereby giving a high average mobility of 13.23 cm2 V–1 s–1 to the flexible OFETs. Therefore, the presented method offers a new opportunity to overcome the trade-off between high performance and good mechanical flexibility in flexible OFETs.