METCO: Atomic-scale study of METallic COntacts on transition metal dichaCogenide single layers
Research project selected under the 2016 call for proposals
Principal Investigator :
Roland CORATGER ()
CEMES (groupes « GNS » et « MEM »)
Type of project : Collaborative Project
Partner team(s) :
LPCNO (groupe « Optoélectronique Quantique »)
Date (start/end) : 2017 - 2019
a) STM image of a MoS 2 surface with atomic resolution observed at low temperature (T = 77K).
b) Optical microscopy image of a MoS 2 single layer.
Abstract
The METCO project deals with the characterization of nanojunctions made of ultrathin metallic contacts deposited on single layers of transition metal dichalcogenides such as MoS 2 or WSe 2 (TMDC). These monolayers have interesting properties. They are good conductors and their optoelectronic properties are very different from those generally observed on thick crystals. Therefore, they are good candidates for future nanocomponents in nanoelectronic, optoelectronic and spintronic devices. However, this supposes a perfect knowledge of the properties of the electrical contact established between the monolayer and the metallic wires surrounding the device in a Field Effect Transistor for example.
The METCO project will be devoted to the study of these contacts at the atomic scale. For this, three groups of two laboratories (CEMES and LPCNO/INSA) are collaborating for synthesis and observation of these nanoobjects as well as calculations of their electronic properties. The TMDC monolayers (mainly MoS 2 et WSe 2 ) will be synthesized and selected using photoluminescence. Thereafter, the ultrathin metallic layers will be deposited either by magnetron sputtering or by Molecular Beam Epitaxy. Then, these metallic layers will be studied using electron diffraction and near field techniques such as STM and AFM working in air and also at low temperature. In the same time, the electronic and atomic properties of the interfaces will be investigated by first principles calculations. These investigations at the atomic scale will be used to choose the best interface, i.e. which favor electron transport and can be used in an operational device.