2016/03/10 by Emily G. Bittle, James I. Basham, Thomas N. Jackson +2 · 1 citation
Engineering · #Organic Electronics and Photovoltaics #Advanced Memory and Neural Computing #Thin-Film Transistor Technologies
paper · pdf · doi:10.1038/ncomms10908
openalex publication_date 2016/03/10 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Parameters used to describe the electrical properties of organic field-effect transistors, such as mobility and threshold voltage, are commonly extracted from measured current-voltage characteristics and interpreted by using the classical metal oxide-semiconductor field-effect transistor model. However, in recent reports of devices with ultra-high mobility (>40 cm(2) V(-1) s(-1)), the device characteristics deviate from this idealized model and show an abrupt turn-on in the drain current when measured as a function of gate voltage. In order to investigate this phenomenon, here we report on single crystal rubrene transistors intentionally fabricated to exhibit an abrupt turn-on. We disentangle the channel properties from the contact resistance by using impedance spectroscopy and show that the current in such devices is governed by a gate bias dependence of the contact resistance. As a result, extracted mobility values from d.c. current-voltage characterization are overestimated by one order of magnitude or more.