Pressure induced structure-property tuning of two dimensional materials

dc.contributor.advisorAkinwande, Dejien
dc.contributor.advisorLin, Jung-Fuen
dc.contributor.committeeMemberWang, Yaguoen
dc.contributor.committeeMemberWang, Zhengen
dc.contributor.committeeMemberHall, Nealen
dc.contributor.committeeMemberDodabalapur, Ananthen
dc.creatorNayak Pradeep, Avinashen
dc.date.accessioned2016-07-25T22:08:10Z
dc.date.accessioned2018-01-22T22:30:17Z
dc.date.available2016-07-25T22:08:10Z
dc.date.available2018-01-22T22:30:17Z
dc.date.issued2015-05
dc.date.submittedMay 2015
dc.date.updated2016-07-25T22:08:10Z
dc.description.abstractControlling 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 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 eV 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, A₁[subscript g], and E₂[subscript g] modes becoming dominant at high pressures. This substantial reversible tunability of the electronic and vibrational property 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.en
dc.description.departmentElectrical and Computer Engineeringen
dc.format.mimetypeapplication/pdfen
dc.identifierdoi:10.15781/T26T0GW52en
dc.identifier.urihttp://hdl.handle.net/2152/39226en
dc.language.isoenen
dc.subject2D materials
dc.subjectTransition metal dichalcogenide
dc.titlePressure induced structure-property tuning of two dimensional materialsen
dc.typeThesisen
dc.type.materialtexten

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