Effect of source-drain electric field on the Meyer-Neldel energy in organic field effect transistors

We studied the influence of the lateral source-drain electric field on the Meyer-Neldel phenomenon observed for the charge mobility measured in C-60-based organic field effect transistors (OFETs). It was found that the characteristic Meyer-Neldel temperature notably shifts with applied source drain electric field. This finding is in excellent agreement with an analytic model recently extended to account also for the field dependence of the charge carrier mobility in materials with a Gaussian density-of-states distribution. As the theoretical model to predict charge carrier mobility is not limited to zero-electric field, it provides a more accurate evaluation of energetic disorder parameters from experimental data measured at arbitrary electric fields. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3584131]