Electroluminescence from a pentacene based ambipolar organic field-effect transistor

Abstract

In this letter light emission from a pentacene-based ambipolar organic field-effect transistor is reported. Electroluminescence appears from a narrow region extending over the entire transistor channel width. The position of the light-emitting recombination zone is spatially controllable by the applied voltages. The current/voltage characteristics of the ambipolar device exhibit a hysteresis caused by trapped electrons in the transistor channel, which is also mirrored in the voltage dependent position of the light-emitting region. From the voltage dependence of the light intensity it can be concluded that Ohmic contacts are formed between pentacene and the utilized metal contacts calcium and gold.