Wafer-scale monolayer organic single-crystalline films and arrays toward high-performance organic electronics

Two-dimensional molecular crystals (2DMCs) stand out as a distinguished class of materials for next-generation flexible electronics, owing to their molecularly thin thickness and impeccable single-crystalline structure. However, scaling up their production without compromising the pristine single-crystalline nature has posed substantial challenges for widespread application. Herein, we introduce a novel seeded dip coating (SDC) technique that produces wafer-scale, monolayer 2DMC films with outstanding charge carrier mobility and remarkable uniformity. The SDC technique induces seeds in situ and effectively separates the nucleation and growth stages, thereby overcoming the paradoxical requirement for supersaturation of both steps. Utilizing the SDC technique, a large-area monolayer 2DMC OFET array was realized, showcasing a leading average mobility of 13.0 cm² V^{− 1} s^{− 1} and an ultra-small mobility coefficient of variation (CV) of 7.5%. The SDC technique offers a universal and scalable pathway for producing larger-area monolayer 2DMC films, paving the way for flexible electronic applications.