Atomic-scale defects and electronic properties of a transferred synthesized MoS2 monolayer
- Resource Type
- Authors
- Blanca Biel; Nataša Vujičić; Fabio Faraguna; Pablo Pou; Borna Pielić; Aurelio Gallardo; Marko Kralj; Ida Delač Marion; Davor Čapeta
- Source
- Subject
- Materials science
Photoluminescence
Band gap
Mechanical Engineering
Scanning tunneling spectroscopy
Analytical chemistry
Bioengineering
02 engineering and technology
General Chemistry
021001 nanoscience & nanotechnology
01 natural sciences
Atomic units
law.invention
Mechanics of Materials
law
0103 physical sciences
Monolayer
General Materials Science
Wafer
Density functional theory
Electrical and Electronic Engineering
Scanning tunneling microscope
010306 general physics
0210 nano-technology
MoS2 monolayer
Ir(111)
atomic defects
scanning tunneling microscopy (STM)
scanning tunneling spectroscopy (STS)
density functional theory (DFT)
photoluminescence (PL)
- Language
- English
MoS2 monolayer samples were synthesized on a SiO2/Si wafer and transferred to Ir(111) for nano- scale characterization. The samples were extensively characterized during every step of the transfer process, and MoS2 on the final substrate was examined down to the atomic level by scanning tunneling microscopy (STM). The procedures conducted yielded high-quality monolayer MoS2 of milimeter-scale size with an average defect density of 2 × 1013 cm–2. The lift-off from the growth substrate was followed by a release of the tensile strain, visible in a widening of the optical band gap measured by photoluminescence. Subsequent transfer to the Ir(111) surface led to a strong drop of this optical signal but without further shifts of characteristic peaks. The electronic band gap was measured by scanning tunneling spectroscopy (STS), revealing n-doping and lateral nano-scale variations. The combined use of STM imaging and density functional theory (DFT) calculations allows us to identify the most recurring point-like defects as S vacancies.