Journal Article

FZJ-2023-02187

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png The MoS 2 -Graphene-Sapphire Heterostructure: Influence of Substrate Properties on the MoS 2 Band Structure

Wördenweber, H.FZJ* ; Grundmann, A. ; Wang, Z.FZJ* ; Hoffmann-Eifert, S.FZJ* ; Kalisch, H. ; Vescan, A. ; Heuken, M. ; Waser, R.FZJ* ; Karthäuser, S. (Corresponding author)FZJ*

2023
Soc. Washington, DC

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/34518  doi:10.1021/acs.jpcc.3c02503

Abstract: Van der Waals MoS2/graphene heterostructures are promising candidates for advanced electronics and optoelectronics beyond graphene. Herein, scanning probe methods and Raman spectroscopy were applied for analysis of the electronic and structural properties of monolayer (ML) and bilayer 2H-MoS2 deposited on single-layer graphene (SLG)-coated sapphire (S) substrates by means of an industrially scalable metal organic chemical vapor deposition process. The SLG/S substrate shows two regions with distinctly different morphology and varied interfacial coupling between SLG and S. ML MoS2 nanosheets grown on the almost free-standing graphene show no detectable interface coupling to the substrate, and a value of 2.23 eV for the MoS2 quasiparticle bandgap is determined. However, if the graphene is involved in hydrogen bonds to the hydroxylated sapphire surface, an increased MoS2/graphene interlayer coupling results, marked by a shift of the conduction band edge toward Fermi energy and a reduction of the ML MoS2 quasiparticle bandgap to 1.98 eV. The surface topography reveals a buckle structure of ML MoS2 in conformity with SLG that is used to determine the dependence of the ML MoS2 bandgap on the interfacial spacing of this heterostructure. In addition, an in-gap acceptor state about 0.9 eV above the valence band minimum of MoS2 has been observed on locally elevated positions on both SLG/S regions, which is attributed to local bending strain in the grown MoS2 nanosheets. These fundamental insights reveal the impact of the underlying substrate on the topography and the band alignment of the ML MoS2/SLG heterostructure and provide the possibility for engineering the quasiparticle bandgap of ML MoS2/SLG grown on controlled substrates that may impact the performance of electronic and optoelectronic devices therewith.

---

Contributing Institute(s):

1. Elektronische Materialien (PGI-7)
2. JARA Institut Green IT (PGI-10)
3. JARA-FIT (JARA-FIT)

Research Program(s):

1. 5233 - Memristive Materials and Devices (POF4-523) (POF4-523)
2. BMBF 16ME0399 - Verbundprojekt: Neuro-inspirierte Technologien der künstlichen Intelligenz für die Elektronik der Zukunft - NEUROTEC II - (BMBF-16ME0399) (BMBF-16ME0399)
3. BMBF 16ME0398K - Verbundprojekt: Neuro-inspirierte Technologien der künstlichen Intelligenz für die Elektronik der Zukunft - NEUROTEC II - (BMBF-16ME0398K) (BMBF-16ME0398K)
4. BMBF 16ME0403 - Verbundprojekt: Neuro-inspirierte Technologien der künstlichen Intelligenz für die Elektronik der Zukunft - NEUROTEC II - (BMBF-16ME0403) (BMBF-16ME0403)
5. BMBF 03ZU1106AA - NeuroSys: Memristor Crossbar Architekturen (Projekt A) - A (03ZU1106AA) (03ZU1106AA)
6. BMBF 03ZU1106AB - NeuroSys: "Memristor Crossbar Architekturen (Projekt A) - B" (BMBF-03ZU1106AB) (BMBF-03ZU1106AB)

Appears in the scientific report 2023

---

Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---