Original title: Experimental and Theoretical Comparative Study of Monolayer and Bulk MoS2 under Compression
Authors: del Corro, Elena ; Morales-García, A. ; Peňa-Alvarez, M. ; Kavan, Ladislav ; Kalbáč, Martin ; Frank, Otakar
Document type: Papers
Conference/Event: NANOCON 2015. International Conference /7./, Brno (CZ), 20151014
Year: 2015
Language: eng
Abstract: Recently, a new family of 2D materials with exceptional optoelectronic properties has stormed into the scene of nanotechnology, the transition metal dichalcogenides (e.g., MoS2). In contrast with graphene, which is a zero band gap semiconductor, many of the single layered materials from this family show a direct band-gap in the visible range. This band-gap can be tuned by several factors, including the thickness of the sample; the transition from a direct to indirect semiconductor state takes place in MoS2 when increasing the number of layers from 1 towards the bulk. Applying strain/stress has been revealed as another tool for promoting changes in the electronic structure of these materials; however, only a few experimental works exist for MoS2. In this work we present a comparative study of single layered and bulk MoS2 subjected to direct out-of-plane compression, using high pressure anvil cells and monitoring with non-resonant Raman spectroscopy; accompanying the results with theoretical DFT studies. In the case of monolayer MoS2 we observe transitions from direct to indirect band-gap semiconductor and to semimetal, analogous to the transitions observed under hydrostatic pressure, but promoted at more accessible pressure ranges (similar to 25 times lower pressure). For bulk MoS2, both regimes, hydrostatic and uniaxial, lead to the semimetallization at similar pressure values, around 30 GPa. Our calculations reveal different driving forces for the metallization in bulk and monolayer samples.
Keywords: high pressure; MoS2; Raman spectroscopy
Project no.: GA14-15357S (CEP), 604391, LL1301 (CEP)
Funding provider: GA ČR, GA MŠk
Host item entry: NANOCON 2015: 7th International Conference, Papers - Full Texts, ISBN 978-80-87294-59-8

Institution: J. Heyrovsky Institute of Physical Chemistry AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0265120

Permalink: http://www.nusl.cz/ntk/nusl-262429


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Research > Institutes ASCR > J. Heyrovsky Institute of Physical Chemistry
Conference materials > Papers