Employing Pneumatic Nozzle Printing for Controlling the Crystal Growth of Small Molecule Organic Semiconductor for Field-Effect Transistors

A pneumatic nozzle-based printing technique that can control the crystallization of small molecule organic semiconductor thin films during deposition is reported. By tuning the printing speed and the substrate temperature, large-sized organic crystals are grown along the printing direction, resulting in field-effect mobility enhancement by 50 times compared to spin-coated films for 6,13-bis(triisopropylsilylethynyl)-pentacene. Furthermore, silver electrodes using the technique to fabricate printed flexible inverters with a gain as high as 16 are printed.