Solution‐printed organic single‐crystalline films hold great potential for achieving low‐cost manufacturing of large‐area and flexible electronics. For practical applications, organic field‐effect transistor arrays must exhibit high performance and small device‐to‐device variation. However, scalable fabrication of highly aligned organic crystalline arrays is rather difficult due to the lack of control over the crystallographic orientation, crystal uniformity, and thickness. Here, a facile solution‐printing method to fabricate centimeter‐sized highly aligned organic crystalline arrays with a thickness of a few molecular layers is reported. In this study, the solution shearing technique is used to produce large‐area, organic highly crystalline thin films. Water‐soluble ink is printed on the hydrophobic surface of organic crystalline films, to selectively protect it, followed by etching. It is shown that the addition of a surfactant dramatically changes the fluid drying dynamics and increases the contact line friction of the aqueous solution to the underlying nonwetting organic crystalline film. As a result, centimeter‐scale highly aligned organic crystalline arrays are successfully prepared on different substrates. The devices based on organic crystalline arrays show good performance and uniformity. This study demonstrates that solution printing is close to industrial application and also expands its applicability to various printed flexible electronics.
2D organic semiconductor crystals (2DOSCs) have extraordinary charge transport capability, adjustable photoelectric properties, and superior flexibility, and have stimulated continuous research interest for next‐generation electronic and optoelectronic applications. The prerequisite for achieving large‐area and high‐throughput optoelectronic device integration is to fabricate high‐resolution 2DOSC arrays. Patterned substrate‐ and template‐assisted self‐assembly is an effective strategy to fabricate OSC arrays. However, the film thickness is difficult to control due to the complicated crystallization process during solvent evaporation. Therefore, the manufacturing of 2DOSC arrays with high‐resolution and controllable molecular‐layer numbers through solution‐based patterning methods remains a challenge. Herein, a two‐step strategy to produce high‐resolution layer‐controlled 2DOSC arrays is reported. First, large‐scale 2DOSCs with well‐defined layer numbers are obtained by a solution‐processed organic semiconductor crystal engineering method. Next, the high‐resolution layer‐controlled 2DOSC arrays are fabricated by a polydimethylsiloxane mold‐assisted selective contact evaporation printing technique. The organic field‐effect transistors (OFETs) based on 2DOSC arrays have high electrical performance and excellent uniformity. The 2,6‐bis(4‐hexylphenyl)anthracene 2DOSC arrays‐based OFETs have a small variation of 12.5% in mobility. This strategy can be applied to various organic semiconductors and pattern arrays. These demonstrations will offer more opportunities for 2DOSCs for integrated optoelectronic devices.
Electrohydrodynamic inkjet (E-jet) printing is a promising technology to fabricate high-performance organic electronic devices due to its high resolution, low-cost and drop-on-demand characteristic. Here, we fabricate top-contact OFETs by using...
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