Transport models in disordered organic semiconductors and their application to the simulation of thin-film transistors

摘要

Relevant organic thin-film transistor (OTFT) simulation software must account for the main specificities of organic semiconductors (OSCs) in terms of free carrier density of states, transport mechanisms and injection/collection properties from/to the device contacts. Among the parameters impacting the OTFT performance carrier mobility is a key parameter. Usual methods to extract the mobility from current-voltage measurements lead to only an apparent, or effective, mobility. The value of the apparent mobility is different from the intrinsic channel OSC mobility. Although the effective mobility actually determines most of a given device performance, therefore providing a very useful technology benchmark, it does not describe the intrinsic OSC material transport properties, and may even be misleading in the route to improving the OTFT fabrication process. To obtain a better understanding of the transport properties in OSCs using OTFT electrical characterization, implementing an appropriate physical mobility model in OTFT current-voltage simulation software is mandatory. The present paper gives a review of the carrier mobility models which can be implemented in OTFT simulation software. The review is restricted to analytical and semi-analytical physical models taking into account the temperature, the carrier concentration and the electric field dependence of the carrier mobility in disordered OSCs. (c) 2019 Society of Chemical Industry