Organic electrochemical transistors manufactured by laser ablation and screen printing

Abstract

The dimensions of the material serving as the channel in organic electrochemical transistors (OECTs) are important for the overall switching performance. Here, a laser ablation step is included in the OECT manufacturing process, in an attempt to shorten the channel length of the OECT. The source and drain electrodes are formed by laser ablation of a previously screen printed carbon-based rectangle, which in this study resulted in an average channel length equal to 25 µm. All other processing steps rely on screen printing, allowing for large-area manufacturing of OECTs and OECT-based circuits on flexible substrates. This approach results in a manufacturing yield of 89%; 178 out of a total of 200 OECTs exhibited an ON/OFF ratio exceeding 1000 with a statistical mean value of 28 000 and reproducible switching performance. OECT-based circuits, here demonstrated by a logic inverter, provide a reasonably high voltage gain of 12. The results thus demonstrate another reliable OECT manufacturing process, based on the combination of laser ablation and screen printing.