Large plate-like organic crystals from direct spin-coating for solution-processed field-effect transistor arrays with high uniformity

Solution-processed organic crystals are important in field-effect transistors because of their highly ordered molecular packing and ease of device fabrication. For practical applications, the patterning of organic crystal transistor arrays is critical. However, uniformity, which concerns the variation in electrical performance among devices fabricated simultaneously on the same substrate, is a common consideration in the commercial applications of the solution-processed organic crystal transistor arrays. Here, a simple approach for fabricating field-effect transistor arrays based on organic plate-like crystals is reported. Through this method, a direct spin-coating process from a mixture solution of organic semiconductor and polymer dielectric can produce organic plate-like crystals. The grain size of the crystals is observed to be hundreds of micrometers. By controlling the concentrations of the active materials, the transistor arrays exhibit high uniformity and good device performance. The results presented in this work promise that this approach is a comparable technology to hydrogenated amorphous silicon-based FETs and is a great candidate for practical applications in electronic devices.

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► Patterned plate-like organic crystals for field-effect transistor arrays.
► Organic crystals were formed by a direct spin-coating process.
► Transistor arrays showed good device performance and high uniformity with small variation.