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TT: Fachverband Tiefe Temperaturen
TT 91: 2D Materials VII: Heterostructures (joint session O/TT)
TT 91.3: Talk
Friday, March 22, 2024, 11:00–11:15, MA 005
Optical properties of van der Waals TMD heterostructures from first-principles — •Riccardo Reho1,2 and Zeila Zanolli1,2 — 1Chemistry Dept., Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands — 2ETSF
Van der Waals (VdW) heterostructures of two-dimensional transition metal dichalcogenides (TMDs) provide a unique platform to investigate rich phenomena stemming from the intricate interactions of charge, spin, and moiré superlattice with many-body effects. Controlling and predicting their optical properties with precision remains challenging.
Employing the ab initio GW-BSE method, we will offer an in-depth microscopic description of the optical properties of TMDs heterostructures. Beyond conventional electronic and absorption analyses, we also delve into the Photoluminescence spectra, leveraging a recent implementation we introduced in the Yambo code. We discuss on the roles of various degrees of freedom, such as mechanical strain and twist alignment. Our findings underscore the importance of structural properties, especially geometrical relaxation and computational subtleties, in ensuring accurate predictions of the band structure and absorption spectra for MoS2/WS2 and MoSe2/WSe2 heterostructures. Notably, we report a pronounced excitonic shift attributed to twisting and strain, shedding light on their profound impact on optical properties.
Keywords: TMDs; spectroscopy; excitons