Tuning the electronic properties of monolayer and bilayer transition metal dichalcogenide compounds under direct out-of-plane compression

0474909 - ÚFCH JH 2018 RIV GB eng J - Článek v odborném periodiku
Morales-García, A. - del Corro, Elena - Kalbáč, Martin - Frank, Otakar
Tuning the electronic properties of monolayer and bilayer transition metal dichalcogenide compounds under direct out-of-plane compression.
Physical Chemistry Chemical Physics. Roč. 19, č. 20 (2017), s. 13333-13340. ISSN 1463-9076. E-ISSN 1463-9084
Grant CEP: GA ČR GA14-15357S; GA MŠMT LL1301
Institucionální podpora: RVO:61388955
Klíčová slova: LAYER MOLYBDENUM-DISULFIDE * TOTAL-ENERGY CALCULATIONS * WAVE BASIS-SET
Obor OECD: Physical chemistry
Impakt faktor: 3.906, rok: 2017

The band-gap modulation of atomically thin semiconductor transition metal dichalcogenides (MX2, M = Mo or W, X = S or Se) under direct out-of-plane compression is systematically studied by means of the density functional theory (DFT) formalism including spin-orbit coupling (SOC) and dispersion correction (D3). The out-of-plane compared with other regimes stress regime significantly reduces the pressure threshold at which the semimetal state is achieved (2.7-3.1 and 1.9-3.2 GPa for mono- and bilayer systems, respectively). Structural, electronic and bonding properties are investigated for a better understanding of the electronic transitions achieved with compression. A notable relationship with the formal ionic radius (M4+ and X2-) is obtained. On one hand, the monolayer systems with the smallest transition metal radius (Mo4+ < W4+) reach the semimetal state at lower stress, on the other hand, for bilayer specimens the transition to semimetal is observed earlier for compounds with the smallest chalcogenide radius (S2- < Se2-). Moreover, the appearance of non-covalent interaction (NCI) domains in the semimetal state confirms that the out-of-plane compression promotes the interaction between sulfur atoms in the single layered systems and reduces the interlayer space in bilayer configurations. Our predictions, supported by experimental evidences in the case of monolayered MoS2, demonstrate new alternative methods for tuning the electronic properties of transition metal dichalcogenides under direct out-of-plane compression.

Trvalý link: http://hdl.handle.net/11104/0271815