Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715629
Title: Electronic properties of molybdenum disulphide calculated from first principles
Author: Hayati, Farzad
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 2017
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Abstract:
The electrical properties of bulk and single-layer molybdenum disulphide and the electrical and magnetic properties of molybdenum disulphide nanoribbons have been investigated using density functional theory within the first principles’ calculation framework. Changes in energy band structure observed during the transition from bulk to single-layer MoS\(_2\) are linked to atomic orbitals through the use of maximally-localised Wannier functions. Extensive structural optimisation studies have been used to explore the effects of stress and strain on the electronic properties of both bulk and single-layer MoS\(_2\). It has been found that the electronic structure and in particular, the energy band gap of MoS\(_2\) nanoribbons are sensitive to the relaxation of the lattice; and consequently, measurements of the electronic properties will depend strongly on both the preparation of the sample and the substrate on which it is deposited. The spin polarised energy band structure and the charge density were used to determine the magnetic states of zigzag nanoribbons. It has been found that both ferromagnetic and anti-ferromagnetic states are equally probable in both passivated and non-passivated zigzag nanoribbons and the calculated result depends on the initial spin configuration prior to optimisation. A new hydrogen passivation structure on the edges of MoS\(_2\) nanoribbons was suggested, which shows zigzag nanoribbons can also become semiconducting. Finally, the electrical and magnetic properties of a novel chiral MoS\(_2\) nanoribbon were modelled, which showed that the chiral MoS\(_2\) nanoribbons can exhibit both semiconducting and ferromagnetic behaviour simultaneously; this has never been previously reported.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.715629  DOI: Not available
Keywords: QC Physics ; QD Chemistry ; TK Electrical engineering. Electronics Nuclear engineering
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