Breaking Fundamental Limitation of Flow‐Induced Anisotropic Growth for Large‐Scale and Fast Printing of Organic Single‐Crystal Films

Abstract Advanced organic electronic technologies have put forward a pressing demand for cost‐effective and high‐throughput fabrication of organic single‐crystal films (OSCFs). However, solution‐printed OSCFs are typically plagued by the existence of abundant structural defects, which pose a formidable challenge to achieving large‐scale and high‐performance organic electronics. Here, it is elucidated that these structural defects are mainly originated from printing flow‐induced anisotropic growth, an important factor that is overlooked for too long. In light of this, a surfactant‐additive printing method is proposed to effectively overcome the anisotropic growth, enabling the deposition of uniform OSCFs over the wafer scale at a high speed of 1.2 mm s −1 at room temperature. The resulting OSCF exhibits appealing performance with a high average mobility up to 10.7 cm 2 V −1 s −1 , which is one of the highest values for flexible organic field‐effect transistor arrays. Moreover, large‐scale OSCF‐based flexible logic circuits, which can be bent without degradation to a radius as small as 4.0 mm and over 1000 cycles are realized. The work provides profound insights into breaking the limitation of flow‐induced anisotropic growth and opens new avenues for printing large‐scale organic single‐crystal electronics.