Electrical characterization of organic (amorphous) electronic materials

Abstract

AbstractOrganic electronic materials, or amorphous electronic materials in general, have relatively low conductivity and this limits their application to the low‐frequency electronics market. To describe electronic conduction in these materials it is common to use percolation [1] or (variable range) hopping theory [2] (the two being equivalent). This is an inheritance from the earlier research in organic materials that were invariably insulators, where conduction was a perturbation – movement of charge was a rare event.Summarizing in this paper our work on organic electronic materials, it is shown that for electronic materials, instead, it is better to revert to classical semiconductor theories, like band theory [3]. If we include a large density of traps in the energy system, all observed phenomena are easily explained. This includes 1. strong temperature dependent charge‐carrier mobility, 2. field‐dependent mobility, 3. anomalous transient behavior. Moreover, it is consistent with observations in many types of devices, ranging from two‐terminal devices such as diodes to three‐terminal devices such as thin‐film transistors [4].(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)