Epitaxial growth and electronic properties of quasi-free-standing rhombohedral <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>WSe</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> bilayers on cub

Rhombohedral-stacked transition metal dichalcogenides (TMDs) break inversion symmetry between adjacent layers, giving rise to an intrinsic out-of-plane ferroelectric polarization. Controlling the formation of this stacking polytype is therefore essential for harnessing ferroelectric effects in two-dimensional materials. In this work, we demonstrate the epitaxial growth of rhombohedral bilayer tungsten diselenide (3R-${\mathrm{WSe}}_{2}$) on a cubic W(110) single crystal by molecular beam epitaxy. We show that selenium passivation of the substrate is key to enable a quasi-van der Waals epitaxy, effectively suppressing strong interfacial bonding and promoting the growth of quasi free-standing bilayer films. The 3R stacking order is confirmed through a combination of Raman spectroscopy and high-resolution angle-resolved photoemission spectroscopy (ARPES), supported by density functional theory (DFT) calculations. ARPES and DFT reveals an indirect-gap electronic structure with the valence-band maximum at the \ensuremath{\Gamma} point, as well as a pronounced spin-orbit-driven splitting of $520\ifmmode\pm\else\textpm\fi{}20$ meV at the K point. Analysis of the measured dispersions yields hole effective masses of $0.46\ifmmode\pm\else\textpm\fi{}0.04\phantom{\rule{0.16em}{0ex}}{m}_{e}$ and $0.75\ifmmode\pm\else\textpm\fi{}0.06\phantom{\rule{0.16em}{0ex}}{m}_{e}$ for the upper and lower valence bands at K point, respectively. These results establish a robust route for synthesizing quasi-free-standing 3R-${\mathrm{WSe}}_{2}$ and provide a platform for exploring the electronic, optical, and ferroelectric functionalities that emerge from inversion-symmetry breaking in layered TMDs. Our findings further highlight the potential of cubic substrates for deterministic fabrication of rhombohedral TMD heterostructures and ferroelectric devices at the nanoscale.

Authors

Institutions

Publication Details

Journal
Physical Review Materials
Published
2026-04-13
DOI
https://doi.org/10.1103/xs47-7hky
Primary Topic
2D Materials and Applications
Type
article
Field-Weighted Citation Impact
0.00

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Epitaxial growth and electronic properties of quasi-free-standing rhombohedral <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>WSe</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> bilayers on cub

Abdelkarim Ouerghi, Iann C. Gerber, Meryem Bouaziz, Julien Chaste et al.
Physical Review Materials
2D Materials and Applications
article

Epitaxial growth and electronic properties of quasi-free-standing rhombohedral <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>WSe</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> bilayers on cub

Abdelkarim Ouerghi, Iann C. Gerber, Meryem Bouaziz, Julien Chaste, F. Oehler, Eva Desgué, Pierre Legagneux, François Bertarn, Niels Chapuis
article en

Abstract

Rhombohedral-stacked transition metal dichalcogenides (TMDs) break inversion symmetry between adjacent layers, giving rise to an intrinsic out-of-plane ferroelectric polarization. Controlling the formation of this stacking polytype is therefore essential for harnessing ferroelectric effects in two-dimensional materials. In this work, we demonstrate the epitaxial growth of rhombohedral bilayer tungsten diselenide (3R-${\mathrm{WSe}}_{2}$) on a cubic W(110) single crystal by molecular beam epitaxy. We show that selenium passivation of the substrate is key to enable a quasi-van der Waals epitaxy, effectively suppressing strong interfacial bonding and promoting the growth of quasi free-standing bilayer films. The 3R stacking order is confirmed through a combination of Raman spectroscopy and high-resolution angle-resolved photoemission spectroscopy (ARPES), supported by density functional theory (DFT) calculations. ARPES and DFT reveals an indirect-gap electronic structure with the valence-band maximum at the \ensuremath{\Gamma} point, as well as a pronounced spin-orbit-driven splitting of $520\ifmmode\pm\else\textpm\fi{}20$ meV at the K point. Analysis of the measured dispersions yields hole effective masses of $0.46\ifmmode\pm\else\textpm\fi{}0.04\phantom{\rule{0.16em}{0ex}}{m}_{e}$ and $0.75\ifmmode\pm\else\textpm\fi{}0.06\phantom{\rule{0.16em}{0ex}}{m}_{e}$ for the upper and lower valence bands at K point, respectively. These results establish a robust route for synthesizing quasi-free-standing 3R-${\mathrm{WSe}}_{2}$ and provide a platform for exploring the electronic, optical, and ferroelectric functionalities that emerge from inversion-symmetry breaking in layered TMDs. Our findings further highlight the potential of cubic substrates for deterministic fabrication of rhombohedral TMD heterostructures and ferroelectric devices at the nanoscale.

Physical Review MaterialsVol. 10(4)
Université Fédérale de Toulouse Midi-Pyrénées (FR), Université Paris-Saclay (FR), Synchrotron soleil (FR), Thales (Australia) (AU), Centre de Nanosciences et de Nanotechnologies (FR), Laboratoire de Physique et Chimie des Nano-Objets (FR)
Agence Nationale de la Recherche, Grand Équipement National De Calcul Intensif
Openalex Percentile: Top 56%
2D Materials and Applications
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.