Extraction of contact resistance and channel parameters from the electrical characteristics of a single bottom-gate/top-contact organic transistor

Abstract

A parameter extraction procedure for staggered-type organic field-effect transistors (OFETs), in which only the electrical characteristics of a single device are needed, was newly considered. The existing differential method and the transition voltage method for evaluating contact and channel parameters in OFETs were complementarily combined. The calibration of the total resistance between the source and the drain was also incorporated to compensate discrepancies in the total resistances calculated from output and transfer characteristics, caused by the existence of nonignorable contact resistance and carrier traps. By using our proposed method, gate-voltage-dependent contact resistance and channel mobility in the linear regime were evaluated for bottom-gate/top-contact pentacene thin-film transistors, and the channel-length dependence of these parameters was investigated. A series of results of parameter extraction confirm the validity of our proposed method, which is advantageous in avoiding the influences of characteristic variations that are frequently observed in practical OFET devices.