LANGUAGE:
Company News

## Tunable Electronic and Dielectric Properties of Molybdenum Disulfide

Datetime:2016/7/18 22:02:20hit:10500

Tunable Electronic and Dielectric Properties of Molybdenum Disulfide. We report tunability in electronic and dielectric properties of a technologically promising nanomaterial MoS 2 . The properties of MoS 2 can be tuned by varying the layer thickness, by applying mechanic strain, by tuning the interlayer distance, and by applying external electric field. Reducing the slab thickness systematically from bulk to monolayers causes blue shift in the band gap energies, thereby, resulting in tunability of the electronic band gap. By reducing the number of layers from bulk to monolayer limit, electron energy loss spectra (EELS) shows red shift in the energies of both $${{\uppi}}$$ and $${{\uppi}} + {{\upsigma}}$$ plasmons. Mechanical strains reduce the band gap of monolayer MoS 2 by causing a direct-to-indirect band gap transitions and finally rendering it into metal at critical values depending on the types of applied strain. Dielectric properties of monolayer MoS 2 too get influenced by the type of applied strain. Imaginary part of dielectric function ( $${{\upvarepsilon}}_{2}$$ ) shows redshift in the structure peak energy on the application of strains with significant dependence on the types of applied strain. In-plane strains also cause semiconductor-metal transitions ( $${\text{e}}_{T}$$ ) in bilayer sheets of MoS 2 . The energy gap of semiconducting bilayer MoS 2 gets reduced continuously by reducing the bilayer separation, eventually rendering it metallic at critical value of interlayer distance. Electrically gated semiconducting bilayer MoS 2 is also found to show reduction in the band gap on increasing the magnitude of electric field and results in band gap closure at a critical value of the field.