Pressure-dependent optical and vibrational properties of monolayer molybdenum disulfide

Avinash P. Nayak, Tribhuwan Pandey, Damien Voiry, Jin Liu, Samuel T. Moran, Ankit Sharma, Cheng Tan, Changhsiao Chen, Lain-Jong Li, Manish U. Chhowalla, Jungfu Lin, Abhishek Kumar Singh, Deji Akinwande

Research output: Contribution to journalArticlepeer-review

194 Scopus citations

Abstract

Controlling the band gap by tuning the lattice structure through pressure engineering is a relatively new route for tailoring the optoelectronic properties of two-dimensional (2D) materials. Here, we investigate the electronic structure and lattice vibrational dynamics of the distorted monolayer 1T-MoS2 (1T′) and the monolayer 2H-MoS2 via a diamond anvil cell (DAC) and density functional theory (DFT) calculations. The direct optical band gap of the monolayer 2H-MoS2 increases by 11.7% from 1.85 to 2.08 eV, which is the highest reported for a 2D transition metal dichalcogenide (TMD) material. DFT calculations reveal a subsequent decrease in the band gap with eventual metallization of the monolayer 2H-MoS2, an overall complex structure-property relation due to the rich band structure of MoS2. Remarkably, the metastable 1T′-MoS2 metallic state remains invariant with pressure, with the J2, A1g, and E2g modes becoming dominant at high pressures. This substantial reversible tunability of the electronic and vibrational properties of the MoS2 family can be extended to other 2D TMDs. These results present an important advance toward controlling the band structure and optoelectronic properties of monolayer MoS2 via pressure, which has vital implications for enhanced device applications.
Original languageEnglish (US)
Pages (from-to)346-353
Number of pages8
JournalNano Letters
Volume15
Issue number1
DOIs
StatePublished - Dec 18 2014

ASJC Scopus subject areas

  • Bioengineering
  • Materials Science(all)
  • Chemistry(all)
  • Mechanical Engineering
  • Condensed Matter Physics

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