We investigate the impact of crystal alignment on excitonic behavior in WSe2/MoS2 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.
@article{arxiv.2506.18607,
title = {Influence of Interlayer Stacking on Optical Behavior in WSe$_{2}$/MoS$_{2}$ van der Waals Heterostructures},
author = {Widad Louafi and Karim Rezouali and Daniele Varsano and Maurizia Palummo and Maurits W. Haverkort and Samir Lounis},
journal= {arXiv preprint arXiv:2506.18607},
year = {2025}
}