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HL: Fachverband Halbleiterphysik

HL 18: 2D Materials and Heterostructures: Emerging Materials and Phenomena

HL 18.10: Talk

Tuesday, March 19, 2024, 12:00–12:15, EW 201

Electronic effects on wrinkled 2D TMDCs — •Mohammadreza Daqiqshirazi and Thomas Brumme — Chair of Theoretical Chemistry, Technische Universität Dresden, Bergstraße 66c, 01069 Dresden, Germany

Strain can be used to change the electronic properties of 2D materials considerably especially since they can undergo strong deformations before breaking. It has been shown that there are various techniques to create wrinkles or folds in 2D materials. The wrinkles exert an inhomogeneous strain field on the 2D material that goes beyond the conventional uniaxial and biaxial strain effects. It is very important to understand these effects as wrinkles and bubbles can also occur during the synthesis or due to the transfer process. Unfortunately, these inhomogeneous strains are rarely studied using fundamental methods because the size of the systems is enormous. Here we investigate the effect of an inhomogeneous strain field in the form of wrinkles in 2D WSe2 monolayers, bilayers and heterostructures of WSe2-MoSe2. We use density functional theory and include spin-orbit coupling in our calculations. We find that spin-orbit coupling and symmetry breaking in monolayers lead to a strong Rashba-like splitting. Furthermore, from the band structures, we can explain the localization of the excitons in certain regions of the systems due to strain fields.

Keywords: Strain; 2D materials; Transition Metal D; transition metal dichalcogenides; Ab initio