In this thesis, we present results of studies of the electronic band structures and related electronic properties of some layered transition metal chalcogenides and their intercalation complexes. The materials investigated include group VIIc transition metal dichalcogenides, and 2H-TaS<SUB>2</SUB> and its lithium-, lead-, and tin-intercalated complexes, as well as dihafnium sulphide and selenide. Both experimental measurements and theoretical elect'onic band structure calculations have been carried out. The types of measurements conducted consist of reflectivity measurements in the energy range from 0.5 eV to 4.5 eV using the home-made reflectivity spectrometer, and electron energy loss measurements in the energy range up to 100 eV using the scanning transmission electron microscope as well as some characterization experiments (structural, chemical composition and thermal properties). The experimental investigations were restricted to the layered group VIIc metal dichalcogenides. All the electronic band structures are calculated using the linearized muffin-tin orbital (LMTO) method, and are reported for the first time except PdTe<SUB>2</SUB> and 2H-TaS<SUB>2</SUB>. The obtained electronic band structures for the Ni-group metal dichalcogenides, and the semiconductor-metal shift in progression from PtS<SUB>2</SUB> through PtSe<SUB>2</SUB> to PtTe<SUB>2</SUB> are discussed in terms of the binding energies of the atomic valence orbitals of the constituent atoms, the local coordination of the metal atoms and the symmetry of the crystals as well as the charge transfer effects. A superlattice structural phase transition is proposed for PtSe<SUB>2</SUB>, which may possibly explain the anomaly observed in the previous transport measurement. The previous photoemission spectra from NiTe<SUB>2</SUB>, PdTe<SUB>2</SUB> and PtTe<SUB>2</SUB>, and dHvA measurement on PdTe<SUB>2</SUB> are compared with their band structures in details, and a good agreement is found. Other available experimental data including the previous transport, optical and magnetic susceptibility measurements as well as the reflectivity and electron energy loss spectra measured in this work are also discussed in terms of these electronic structures. The band structure calculations for dihafnium chalcogenides predict that these materials are metals. They also suggest that there is a strong bonding between Hf atoms in the adjacent layers, thus giving rise to the rigidity in the c-direction which may preclude the intercalation of these materials. The results for 2H-TaS<SUB>2</SUB> and its intercalation complexes show that the rigid band model is essentially correct for 2H-LiTaS<SUB>2</SUB> but is an oversimplication for the post-transition metal intercalation compounds. Changes in the electronic structure upon intercalation are discussed in terms of the intercalant-host charge transfer and the hybridisation between the host states and the intercalation valence orbitals. Electrical conduction in 2H-PbTaS<SUB>2</SUB> and SnTaS<SUB>2</SUB> is found to be largely due to the p-valence electrons from the intercalant Pb (Sn) layers, resulting in the considerable increase in the superconducting transition temperature following intercalation. The results are also compared with the observed optical and transport properties and a broad agreement is found. The band structures and the electronic properties of other layered transition metal dichalcogenides and their intercalation complexes, as well as the band structure calculation techniques for the layered compounds are also reviewed in this thesis.

Wan, Xi. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 128-132). Also available in electronic version.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xii, 134 p.; also includes graphics. Includes abstract and vita. Advisor: Noriko Katsube, Dept. of Mechanical Engineering. Includes bibliographical references (p. 121-125).

Semiconductors are characterized by atomic resolution imaging and density of states measurements (DOS) obtained through the use of a scanning tunneling microscope (STM). The DOS of the conduction and valence bands can be measured separately with a STM as opposed to an optical measurement which measures only the joint DOS. Layered-structure semiconductors are characterized both in the bulk form and in the isolated cluster form. Images of three bulk layered-structure semiconductors, MoS₂, WSe₂, and SnS₂, were obtained with both positive and negative sample-to-tip bias voltages. Curves of tunneling current as a function of bias voltage were measured, from which the DOS of the valence and conduction bands can be inferred. We obtained an atomically resolved image of an isolated fragment of a semi-conductor cluster which was deposited on a graphite surface from a colloidal suspension of BiI₃. Also imaged were clusters of MoS₂ layered-structure semiconductors.

No description available.

Thesis (Ph.D.)--Baylor University, 2007. / Includes bibliographical references (p. 107-109).

Thesis (Ph.D.)--McMaster University (Canada), 1993. / Source: Dissertation Abstracts International, Volume: 54-12, Section: B, page: 6259. Adviser: Jules P. Carbotte.

by Ranganathan Venugopal. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 150-165). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

No description available.