Details

Autor(en) / Beteiligte

• Nevola, D.
• Hoffman, B.C.
• Bataller, A.
• Ade, H.
• Gundogdu, K.
• Dougherty, D.B.

Titel

Rigid valence band shift due to molecular surface counter-doping of MoS2

Ist Teil von

• Surface science, 2019-01, Vol.679, p.254-258

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •One layer of TCNQ accepts electrons from MoS2 surface•MoS2 bands are shifted rigidly by charge transfer to TCNQ•Rigid band shifts can control optoelectronic properties without altering details of band structure Adsorption of the acceptor material tetracyanoquinodimethane can control optoelectronic properties of MoS2 by accepting defect generated excess negative charge from the surface that would otherwise interfere with radiative decay processes. Angle Resolved Photoelectron Spectroscopy measurements show that the MoS2 band structure near the Γ point shifts rigidly upward by ∼0.2 eV for a complete surface coverage of acceptor species as expected for an upward Fermi level shift due to charge transfer to the TCNQ. The molecular adsorbate orbitals visible in photoemission are indicative of an anionic species, consistent with interfacial charge transfer but without evidence for hybrid states arising from covalent adsorbate-surface interactions. Thus, our interface studies support the notion that molecular adsorbates are a useful tool for controlling optoelectronic functionality in 2D materials without fundamentally modifying their favorable band structures. [Display omitted]