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Main Authors: López, Pablo Hernández, Pirker, Luka, Weston, Astrid, Kayal, Arijit, Nadas, Rafael, Fernández, Adrián Dewambrechies, Rodríguez, Álvaro, Gorbachev, Roman, Bolotin, Kirill I., Frank, Otakar, Heeg, Sebastian
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2605.20869
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author López, Pablo Hernández
Pirker, Luka
Weston, Astrid
Kayal, Arijit
Nadas, Rafael
Fernández, Adrián Dewambrechies
Rodríguez, Álvaro
Gorbachev, Roman
Bolotin, Kirill I.
Frank, Otakar
Heeg, Sebastian
author_facet López, Pablo Hernández
Pirker, Luka
Weston, Astrid
Kayal, Arijit
Nadas, Rafael
Fernández, Adrián Dewambrechies
Rodríguez, Álvaro
Gorbachev, Roman
Bolotin, Kirill I.
Frank, Otakar
Heeg, Sebastian
contents Novel excitonic phenomena emerging in transition metal dichalcogenide (TMDC) heterostructures belong to the most exciting topics in contemporary physics of van der Waals materials. Interlayer excitons (IXs) stand out among those due to their long radiative lifetimes and tunability by electric fields, strain, and twist angle. However, many ambiguities persist in the optical identification and manipulation of IXs, highlighting the need for reliable spectroscopic criteria that distinguish interlayer species from spurious signals. Here, we present a decision-tree protocol that evaluates interlayer coupling via intralayer exciton quenching and correlates photoluminescence (PL) with atomic force microscopy (AFM) to correctly assign room-temperature PL features in TMDC-based heterostructures. Applying this protocol, we identify momentum-direct IX between the K valleys of the two layers (KK-IX) in MoS2-MoSe2 and MoS2-WSe2 heterostructures at room temperature. In contrast, our protocol contests the reported bright, momentum-indirect, twist-angle-independent $Γ$K-IX in MoS2-WSe2. Comprehensive experimental data, including infrared and tip-enhanced photoluminescence (TEPL) with sub-diffraction-limited resolution, show no compelling evidence for this excitonic species, despite numerous reports. Instead, the spectroscopic features previously assigned to this $Γ$K-IX originate from locally strained WSe2 at topographical inhomogeneities of the heterostructure interface, underscoring the need for robust, spatially resolved characterization of real-world samples in this highly accessible field and providing a generally applicable framework for identifying interlayer excitons in 2D semiconductor heterostructures.
format Preprint
id arxiv_https___arxiv_org_abs_2605_20869
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The Topography Trap: Sifting Interlayer Excitons from Strain-Related Artifacts in Real-World 2D Hetrostructures
López, Pablo Hernández
Pirker, Luka
Weston, Astrid
Kayal, Arijit
Nadas, Rafael
Fernández, Adrián Dewambrechies
Rodríguez, Álvaro
Gorbachev, Roman
Bolotin, Kirill I.
Frank, Otakar
Heeg, Sebastian
Mesoscale and Nanoscale Physics
Novel excitonic phenomena emerging in transition metal dichalcogenide (TMDC) heterostructures belong to the most exciting topics in contemporary physics of van der Waals materials. Interlayer excitons (IXs) stand out among those due to their long radiative lifetimes and tunability by electric fields, strain, and twist angle. However, many ambiguities persist in the optical identification and manipulation of IXs, highlighting the need for reliable spectroscopic criteria that distinguish interlayer species from spurious signals. Here, we present a decision-tree protocol that evaluates interlayer coupling via intralayer exciton quenching and correlates photoluminescence (PL) with atomic force microscopy (AFM) to correctly assign room-temperature PL features in TMDC-based heterostructures. Applying this protocol, we identify momentum-direct IX between the K valleys of the two layers (KK-IX) in MoS2-MoSe2 and MoS2-WSe2 heterostructures at room temperature. In contrast, our protocol contests the reported bright, momentum-indirect, twist-angle-independent $Γ$K-IX in MoS2-WSe2. Comprehensive experimental data, including infrared and tip-enhanced photoluminescence (TEPL) with sub-diffraction-limited resolution, show no compelling evidence for this excitonic species, despite numerous reports. Instead, the spectroscopic features previously assigned to this $Γ$K-IX originate from locally strained WSe2 at topographical inhomogeneities of the heterostructure interface, underscoring the need for robust, spatially resolved characterization of real-world samples in this highly accessible field and providing a generally applicable framework for identifying interlayer excitons in 2D semiconductor heterostructures.
title The Topography Trap: Sifting Interlayer Excitons from Strain-Related Artifacts in Real-World 2D Hetrostructures
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2605.20869