IMPOSING BIAXIAL STRAIN ON 2D LAYERED MATERIALS BY LIQUID-INDUCED SWELLING OF SUPPORTING POLYMER

1,2 SAMPATHKUMAR Krishna
Co-authors:
1 PEKAREK Jan 2 FRANK Otakar
Institutions:
1 CEITEC - Brno University of Technology, Brno, Czech Republic, EU, krishna.sampathkumar@ceitec.vutbr.cz
2 J.Heyrovsky Institute of Physical Chemistry of the CAS, Prague, Czech Republic, EU, otakar.frank@jh-inst.cas.cz
Conference:
12th International Conference on Nanomaterials - Research & Application, Brno, Czech Republic, EU, October 21 - 23, 2020
Proceedings:
Proceedings 12th International Conference on Nanomaterials - Research & Application
Pages:
50-56
ISBN:
978-80-87294-98-7
ISSN:
2694-930X
Published:
28th December 2020
Proceedings of the conference have been sent to Web of Science and Scopus for evaluation and potential indexing.
Metrics:
145 views / 48 downloads
Abstract

2D layered materials promise to revolutionize the field of electronics, photonics, optoelectronics, energy storage, and sensing, etc. 2D materials have exceptional mechanical properties, with critical elongation >10%. Employing the strain to manipulate the electronic structure of these 2D materials could lead to further improvement of their implementation in many aspects. The ease of manipulation of their electronic structure can be one of the critical factors for their utilization in photonic devices. Apart from the strain, which decreases (increases) the bandgap energy at the rate of ~100 meV under 1% of biaxial tension (compression), also the layer number causes bandgap energy change of, e.g., 0.5 eV between bulk (1.3 eV) and monolayer MoS2 (1.8 eV). In our work, we focus on using the swelling behavior of PMMA/SU8 polymer in methanol to impose the strain on 2D layered materials. In the first trials, we have shown that it is possible to reach a strain gradient from 0 to ~0.5% of biaxial strain via simple swelling of polymer substrates, both for graphene [1] and transition metal di-chalcogenides (TMDC) like MoS2. Raman spectroscopy was used to probe the lattice strain in the materials through measuring changes of vibrational frequencies, and photoluminescence was used to probe the strain-induced bandgap character and energy in TMDC at room temperature. The surface corrugation of the 2D material after the soaking was recorded with the help of atomic force microscope (AFM).

Keywords: 2D material, graphene, TMDC, strain engineering, biaxial strain

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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