Influence of the gate bias stress on the stability of n-type organic field-effect transistors based on dicyanovinylene–dihydroindenofluorene semiconductors

Abstract

The electrical stabilities of n-type Organic Field-Effect Transistors (OFETs) based on dihydroindeno[1,2-b]fluorene and dihydroindeno[2,1-b]fluorene derivatives have been studied. These OFETs incorporate epoxy-based photoresist SU-8 as the gate insulator. The comparison of the electrical stability through gate bias stress measurements as a function of voltage and temperature stress shows that the instabilities of these OFETs result from different phenomena. Different models have been used to analyse the instabilities of the devices and these are discussed. As the two molecules only differ by their geometry and their substitution, this study shows how slight structural modifications of the semiconductor molecular structure induce electrical instabilities in the corresponding OFETs arising from different features.