Ambipolar organic field-effect transistor based on an organic heterostructure

Abstract

Ambipolar charge injection and transport are a prerequisite for a light-emitting organic fieldeffect transistor (OFET). Organic materials, however, typically show unipolar charge-carrier transport characteristics. Consequently, organic thin-film field-effect transistors based on a single material as active layer can typically either be operated as p- or as n-channel device. In this article we show that by using a heterostructure with pentacene as hole-transport and N,N′-Ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13H27) as electron-transport material, ambipolar characteristics, i.e., simultaneous p- and n-channel formation, can be observed in a single device. An OFET structure is investigated in which electrons and holes are injected from Mg top and Au bottom contacts into the PTCDI-C13H27 and pentacene layers, respectively. Our device exhibits electron and hole mobilities of 3×10−3 and 1×10−4 cm2/V s, respectively. This device architecture serves as a model structure for ambipolar field-effect transistors, which are a prerequisite for light-emitting field-effect transistors.

Light-emitting organic field-effect transistor using an organic heterostructure within the transistor channel

“…20 At a certain drain voltage, the electron current in the n-type material at the p-n interface is equal to the hole current in the p-type material. In contrast to previously published LEOFETs, 15,16,19 increasing |V D | beyond this voltage leads to a saturation of the current. This is explained by the fact that a further increase of |V D | does not lead to an increase of the hole current.…”

Air-stable ambipolar organic transistors

“…Bilayer-type ambipolar organic transistors based on the p / n heterostructure concept have also been demonstrated. 10 Realization of ambipolar organic OFETs based on a single semiconductor, on the other hand, has been proven to be much more difficult mainly due to the poor environmental stability of the n-channel operation. 1,5,9,11,12 Only recently single component air-stable ambipolar OFETs and logic circuits have been demonstrated.…”

Ambipolar light-emitting organic field-effect transistor

“…15) as well as of pentacene and N , NЈ-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13). 16 Ambipolar transport in a wide-band-gap organic material, necessary for light emission in the visible region, is difficult to achieve because of impurity-induced traps. 17 A viable way to circumvent this problem is to mix electron-and hole-transporting moieties into one phase, as was demonstrated with solution-processed OFETs in Refs.…”