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arXiv · 2506.18607

Influence of Interlayer Stacking on Optical Behavior in WSe$_{2}$/MoS$_{2}$ van der Waals Heterostructures

Widad Louafi·Karim Rezouali·Daniele Varsano·Maurizia Palummo·Maurits W. Haverkort·Samir Lounis
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Abstract

We investigate the impact of crystal alignment on excitonic behavior in WSe$_{2}$/MoS$_{2}$ van der Waals heterostructures by comparing eclipsed (AA) and staggered (AB) stacking configurations. Our first-principles and symmetry-based analysis reveal that interlayer stacking symmetry plays a central role in determining the nature of electron-hole pairs. We uncover a rich variety of excitonic states, including spatially confined two-dimensional (2D) excitons, delocalized three-dimensional (3D) excitons, and charge-transfer (CT) excitons with interlayer character. The dimensionality and optical activity of these excitons are governed by the interplay among orbital character, interlayer hybridization, and symmetry-imposed selection rules. Our findings establish general principles for engineering excitonic properties in van der Waals heterostructures through controlled layer orientation and stacking order.

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Widad Louafi, Karim Rezouali, Daniele Varsano, Maurizia Palummo, Maurits W. Haverkort, Samir Lounis. 2025-06-23. Influence of Interlayer Stacking on Optical Behavior in WSe$_{2}$/MoS$_{2}$ van der Waals Heterostructures. https://arxiv.org/abs/2506.18607

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