Theoretical characterisation of point defects on a MoS 2 monolayer by scanning tunnelling microscopy

C González 1, 2 B Biel 2 Yannick J. Dappe 1
1 GMT - Groupe Modélisation et Théorie
SPEC - UMR3680 - Service de physique de l'état condensé, IRAMIS - Institut Rayonnement Matière de Saclay
Abstract : Different S and Mo vacancies as well as their corresponding antisite defects in a free-standing MoS 2 monolayer are analysed by means of scanning tunnelling microscopy (STM) simulations. Our theoretical methodology, based on the Keldysh nonequilibrium Green function formalism within the density functional theory (DFT) approach, is applied to simulate STM images for different voltages and tip heights. Combining the geometrical and electronic effects, all features of the different STM images can be explained, providing a valuable guide for future experiments. Our results confirm previous reports on S atom imaging, but also reveal a strong dependence on the applied bias for vacancies and antisite defects that include extra S atoms. By contrast, when additional Mo atoms cover the S vacancies, the MoS 2 gap vanishes and a bias-independent bright protrusion is obtained in the STM image. Finally, we show that the inclusion of these point defects promotes the emergence of reactive dangling bonds that may act as efficient adsorption sites for external adsorbates.
Type de document :
Article dans une revue
Nanotechnology, Institute of Physics, 2016, 27 (10), pp.105702. 〈10.1088/0957-4484/27/10/105702〉
Liste complète des métadonnées

https://hal-cea.archives-ouvertes.fr/cea-01490962
Contributeur : Dominique Girard <>
Soumis le : jeudi 16 mars 2017 - 11:05:36
Dernière modification le : jeudi 15 mars 2018 - 15:05:07
Document(s) archivé(s) le : samedi 17 juin 2017 - 13:20:17

Fichier

González_2016_27_105702.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Citation

C González, B Biel, Yannick J. Dappe. Theoretical characterisation of point defects on a MoS 2 monolayer by scanning tunnelling microscopy. Nanotechnology, Institute of Physics, 2016, 27 (10), pp.105702. 〈10.1088/0957-4484/27/10/105702〉. 〈cea-01490962〉

Partager

Métriques

Consultations de la notice

349

Téléchargements de fichiers

208