Solution-processed organic crystals written directly with a rollerball pen for field-effect transistors

•Organic semiconducting crystals were directly written by rollerball pens for OFETs.•A facile and rapid approach for the growth of solution-processed organic crystals.•High performance with μFET of 0.7 cm2/Vs and on/off ratio of 107 was obtained.•Solution flowing behavior benefits formation of crystals with large grain sizes.

To deposit organic semiconducting crystals from solution, we propose the use of a rollerball pen as a simple and promising tool. These organic crystal grains of dioctylbenzothienobenzothiophene measured several hundred micrometers. The fabricated OFETs exhibited good device performance with a field-effect mobility (μFET) of 0.7 cm2/Vs and an on-off ratio of more than 107. Simulation results reveal that the flow behavior of solution from the pen refill tube to the substrate intrinsically enhances the formation of large organic crystals.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide