Open AccessBalanced Ambipolar Charge Transport in Phenacene/Perylene Heterojunction-Based Organic Field-Effect Transistors
Author(s) -
Tomoya Taguchi,
F. Chiarella,
Mario Barra,
Federico Chianese,
Yoshihiro Kubozono,
A. Cassinese
Publication year - 2021
Publication title -
acs applied materials and interfaces
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.0c20140
Subject(s) - ambipolar diffusion , materials science , organic semiconductor , optoelectronics , organic electronics , heterojunction , transistor , organic solar cell , field effect transistor , semiconductor , organic field effect transistor , kelvin probe force microscope , dipole , nanotechnology , active layer , pentacene , electron , layer (electronics) , thin film transistor , voltage , polymer , chemistry , physics , quantum mechanics , composite material , atomic force microscopy , organic chemistry
Electronic devices relying on the combination of different conjugated organic materials are considerably appealing for their potential use in many applications such as photovoltaics, light emission, and digital/analog circuitry. In this study, the electrical response of field-effect transistors achieved through the evaporation of picene and PDIF-CN 2 molecules, two well-known organic semiconductors with remarkable charge transport properties, was investigated. With the main goal to get a balanced ambipolar response, various device configurations bearing double-layer, triple-layer, and codeposited active channels were analyzed. The most suitable choices for the layer deposition processes, the related characteristic parameters, and the electrode position were identified to this purpose. In this way, ambipolar organic field-effect transistors exhibiting balanced mobility values exceeding 0.1 cm 2 V -1 s -1 for both electrons and holes were obtained. These experimental results highlight also how the combination between picene and PDIF-CN 2 layers allows tuning the threshold voltages of the p-type response. Scanning Kelvin probe microscopy (SKPM) images acquired on picene/PDIF-CN 2 heterojunctions suggest the presence of an interface dipole between the two organic layers. This feature is related to the partial accumulation of space charge at the interface being enhanced when the electrons are depleted in the underlayer.