INVESTIGADORES
BONETTO fernando Jose
congresos y reuniones científicas
Título:
Molybdenum sulphide: understanding surface-bulk excitations
Autor/es:
P. BUITRAGO; S. MONTORO; S. RODRIGUEZ; E. ALBANESI; R. VIDAL; F. BONETTO
Lugar:
Sao Paulo, Brasil
Reunión:
Encuentro; Autumn Meeting 2022 of the Brazilian Physical Society; 2022
Institución organizadora:
Sociedade Brasileira de Fisica
Resumen:
Molybdenum sulphide (MoS2) is a semiconductor of the family of transition metaldichalcogenides (TMDC). By reducing the dimension of the material, the band gap canchange from indirect (1.2 eV for bulk) to direct (1.9 eV for a monolayer). This particularfeature makes it a promising candidate for nanoscale applications. Therefore, andin order to control the functionality of new technological nanostructures, it is essentialto study its opto-electronic properties. Reflection Electron Energy Loss Spectroscopy(REELS) and Auger Electron Spectroscopy (AES), are highly surface sensitive techniquesand provide relevant information on the response of solid state electrons toincident charged particles. In this study, we made a REELS analysis of MoS2 to recogniseelectronic losses due to collective oscillations generated on the sample surface. Inaddition, the study was complemented with AES analysis to identify stoichiometricchanges generated by sputtering. First, the influence on the peaks signal intensityand the electronic distribution was examined by varying the angle of incidence of theelectrons. After that, the REELS distributions at different primary electron energieswere measured and compared. Thus, it is possible to link each electronic signal loss todifferent physical processes. All experiments were carried out under ultrahigh vacuumconditions and samples were checked to be free of surface contamination. Metallicmolybdenum was previously studied and used as a reference material.