Organic Materials for Multifunctional Transistor-Based Devices

Organic field-effect transistors (OFETs) are “soft material” versions of accumulationmode silicon-based FETs, where a gate field across a dielectric induces a conductive charge channel at the interface of the dielectric with a semiconductor, between source and drain electrodes. Charge carrier mobilities >0.01 and on/off ratios >10,000 are routinely obtained, adequate for a few specialized applications such as electrophoretic pixel switches but well below standards established for silicon microprocessor technology. Still, progress that has been made in solution-phase semiconductor deposition and the printing of contacts and dielectrics stimulates the development of OFET circuits for situations where extreme low cost, large area, and mechanical flexibility are important. Circuits with hundreds of OFETs have been demonstrated and a prototype OFETcontrolled black-on-white “electronic ink” sign has been fabricated.