Oliva, Robert and Wozniak, Tomasz and Faria, Paulo E. and Dybala, Filip and Kopaczek, Jan and Fabian, Jaroslav and Kudrawiec, Robert (2022) Strong Substrate Strain Effects in Multilayered WS2 Revealed by High-Pressure Optical Measurements. ACS APPLIED MATERIALS & INTERFACES, 14 (17). pp. 19857-19868. ISSN 1944-8244, 1944-8252
Full text not available from this repository. (Request a copy)Abstract
The optical properties of two-dimensional materials can be effectively tuned by strain induced from a deformable substrate. In the present work we combine first-principles calculations based on density functional theory and the effective Bethe-Salpeter equation with high-pressure optical measurements to thoroughly describe the effect of strain and dielectric environment onto the electronic band structure and optical properties of a few-layered transition-metal dichalcogenide. Our results show that WS2 remains fully adhered to the substrate at least up to a -0.6% in-plane compressive strain for a wide range of substrate materials. We provide a useful model to describe effect of strain on the optical gap energy. The corresponding experimentally determined out-of-plane and in-plane stress gauge factors for WS2 monolayers are -8 and 24 meV/GPa, respectively. The exceptionally large in-plane gauge factor confirms transition metal dichalcogenides as very promising candidates for flexible functionalities. Finally, we discuss the pressure evolution of an optical transition closely lying to the A exciton for bulk WS2 as well as the direct-to-indirect transition of the monolayer upon compression.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ELECTRON-HOLE EXCITATIONS; LAYER MOS2; FEW-LAYER; BAND-GAP; MONOLAYER; SINGLE; SPECTROSCOPY; SEMICONDUCTORS; MODULATION; TRANSITION; high pressure; two-dimensional materials; density functional theory; TMDCS; modulated spectroscopy |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Jaroslav Fabian |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 16 Feb 2024 05:22 |
| Last Modified: | 16 Feb 2024 05:22 |
| URI: | https://pred.uni-regensburg.de/id/eprint/57827 |
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