Current modulation of a hygroscopic insulator organic field-effect transistor

We have fabricated solution processable polymer transistors with high conductivity, requiring only a few volts for obtaining good current modulation. The devices can be fabricated and operated in air and the operation is greatly enhanced in humid atmosphere. Devices reach an On/Off ratio of about 600 and a subthreshold swing of 500 mV per decade operating on voltages less than 2 V. In this letter the mechanism behind the current modulation is investigated, and we show that the current is modulated through ion-assisted oxidation and reduction of the semiconductor by ions moving vertically in the insulator material to the transistor channel. (C) 2004 American Institute of Physics.