Conservation of the injection and transit time ratio in organic field-effect transistors: A thermally accelerated aging study

Abstract

A thermally accelerated aging for degradation study was used to evaluate the degradation of organic transistor with shallow and deeps traps. A negative threshold voltage shift related to the increase of trapped charge density during the aging was only observed for device with initial shallow traps, while no shift was recorded for devices with deep traps. However, a decrease in the mobility was detected, and an almost constant contact resistance was estimated for both types of devices. Analysis of the potential distribution revealed the conservation of the potential drop on the injection electrode and across the channel region during the entire degradation process. As a result, the ratio of the injection and transit times was conserved and was independent from the shallow traps that were induced by accelerated aging.

Coupling between Transport and Injection Properties of Pentacene Field-Effect Transistors with Different Morphologies

“…( 1) is valid when the injection and transport properties are coupled to each other, as we have reported in our previous papers. 26,27) The model proposed here is very simple, but it effectively elucidates the physics behind carrier injection and transport in organic transistors. The relations derived are valid for the gradual channel approximation proposed by Shockley.…”