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Band Alignment in As‐Transferred and Annealed Graphene/MoS 2 Heterostructures
Author(s) -
Romanov Roman I.,
Slavich Aleksandr S.,
Kozodaev Maxim G.,
Myakota Denis I.,
Lebedinskii Yuri Y.,
Novikov Sergey M.,
Markeev Andrey M.
Publication year - 2020
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201900406
Subject(s) - x ray photoelectron spectroscopy , graphene , raman spectroscopy , materials science , heterojunction , annealing (glass) , analytical chemistry (journal) , spectroscopy , optoelectronics , nanotechnology , chemistry , nuclear magnetic resonance , optics , physics , chromatography , composite material , quantum mechanics
The band alignment in the graphene/MoS 2 van der Waals heterostructures (vdWHs) is investigated by Raman spectroscopy and X‐ray photoelectron spectroscopy (XPS) to understand the transfer‐ and annealing‐induced change of electronic properties. Raman spectroscopy indicates that partial electron redistribution between the MoS 2 and graphene layers occurs when brought into contact, resulting in a hole concentration decrease in graphene from 1 × 10 13 to 7 × 10 12 cm −2 . The additional thermal annealing at 400 °C further decreases the hole concentration down to 3 × 10 12 cm −2 and leads to a MoS 2 valence band offset increase by 0.2 eV. The annealing procedure also results in a visible decrease in adsorbed carbon‐ and oxygen‐containing contaminants, and this decrease is clearly detected by XPS. Thus, the combination of Raman spectroscopy and XPS provides a powerful diagnostic tool for the electronic properties at each stage of vdWHs preparation, allowing the attainment of 2D vdWHs with the desired properties.