Atomic-Scale Electric Potential Landscape across Molecularly Gated Bilayer MoS<sub>2</sub> Resolved by Photoemission.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40916905.
- Also identified by DOI 10.1021/acsnano.5c10363 and PMC identifier 12445001.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Electric gating in atomically thin field-effect devices based on transition-metal dichalcogenides has recently been employed to manipulate their excitonic states, even producing exotic phases of matter, such as an excitonic insulator or Bose-Einstein condensate. Here, we mimic the electric gating effect of a bilayer-MoS<sub>2</sub> on graphite by charge transfer induced by the adsorption of molecular p- and n-type dopants. The electric fields produced are evaluated from the electronic energy-level realignment and Stark splitting determined by X-ray and UV photoelectron spectroscopy measurements and compare very well with literature values obtained by optical spectroscopy for similar systems. We then show that analysis of the inhomogeneous broadening and energy shifts of the quantum-well states of the valence band allows extraction of the full electric potential profile and charge-density redistribution across the entire heterojunction with atomic-scale precision, which is not accessible by other methods.