Tutorial: Organic field-effect transistors: Materials, structure and operation

Chemical versatility and compatibility with a vast array of processing techniques has led to the incorporation of organic semiconductors in various electronic and opto-electronic devices. One such device is the organic field-effect transistor (OFET). In this tutorial, we describe the structure, operation, and characterization of OFETs. Following a short historical perspective, we introduce the architectures possible for OFETs and then describe the device physics and the methods for extracting relevant device parameters. We then provide a brief overview of the myriad organic semiconductors and deposition methods that were adopted for OFETs in the past decades. Non-ideal device characteristics, including contact resistance, are then discussed along with their effects on electrical performance and on the accuracy of extracting device parameters. Finally, we highlight several measurements involving OFETs that allow access to fundamental properties of organic semiconductors and the mechanism of charge transport in these materials.