Název: Experimental and Theoretical Comparative Study of Monolayer and Bulk MoS2 under Compression
Autoři: del Corro, Elena ; Morales-García, A. ; Peňa-Alvarez, M. ; Kavan, Ladislav ; Kalbáč, Martin ; Frank, Otakar
Typ dokumentu: Příspěvky z konference
Konference/Akce: NANOCON 2015. International Conference /7./, Brno (CZ), 20151014
Rok: 2015
Jazyk: eng
Abstrakt: 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.
Klíčová slova: high pressure; MoS2; Raman spectroscopy
Číslo projektu: GA14-15357S (CEP), 604391, LL1301 (CEP)
Poskytovatel projektu: GA ČR, GA MŠk
Zdrojový dokument: NANOCON 2015: 7th International Conference, Papers - Full Texts, ISBN 978-80-87294-59-8

Instituce: Ústav fyzikální chemie J. Heyrovského AV ČR (web)
Informace o dostupnosti dokumentu: Dokument je dostupný v příslušném ústavu Akademie věd ČR.
Původní záznam: http://hdl.handle.net/11104/0265120

Trvalý odkaz NUŠL: http://www.nusl.cz/ntk/nusl-262429


Záznam je zařazen do těchto sbírek:
Věda a výzkum > AV ČR > Ústav fyzikální chemie J. Heyrovského
Konferenční materiály > Příspěvky z konference