Numerical Simulations and In Situ Optical Microscopy Connecting Flow Pattern, Crystallization, and Thin‐Film Properties for Organic Transistors with Superior Device‐to‐Device Uniformity

Abstract Currently, due to the lack of precise control of flow behavior and the understanding of how it influences thin‐film crystallization, strict tuning of thin‐film properties during solution‐based coating is difficult. In this work, a continuous‐flow microfluidic‐channel‐based meniscus‐guided coating (CoMiC) is introduced, which is a system that enables manipulation of flow patterns and analysis connecting flow pattern, crystallization, and thin‐film properties. Continuous supply of a solution of an organic semiconductor with various flow patterns is generated using microfluidic channels. 3D numerical simulations and in situ microscopy allow the tracking of the flow pattern along its entire path (from within the microfluidic channel to near the liquid–solid boundary), and enable direct observation of thin‐film crystallization process. In particular, the generation of chaotic flow re…