Vertical channel all-organic thin-film transistors

Technologically simple and cost-effective processes are essential for the fabrication of organic electronic devices. In this letter, we present a concept for making vertical channel all-organic thin-film transistors on glass substrate. This concept avoids the need for patterning processes with high lateral resolution by defining the channel length through the thickness of an insulating layer. Our devices are based on commercially available poly(ethylene dioxythiophene)/poly(styrene sulfonate) dispersion for source, drain, and gate electrodes, photoresist as the insulating layer and photosensitized poly(vinyl alcohol) as the gate insulator. Pentacene was used as the organic semiconductor. Functional devices with channel length of 2.4 μm and width of 1 mm have been realized, and we report electrical characteristics of these devices.