Electronic Structure and Electronic Transitions in Layered Materials

This new volume in the series Physics and Chemistry of Materials with Layered Structures satisfies the need for a comprehensive review of the progress made in the decade 1972-1982 in the field of the electronic properties of layer compounds. Some recent theoretical and experimental developments are highlighted by authori­ tative physicists active in current research. The previous books of this series covering similar topics are volumes 3 and 4. The present review is mainly intended to fulfill the gap up to 1982 and part of 1983. I am indebted to all the authors for their friendly co-operation and continuous effort in preparing the contributions in their own fields of competence. I am sure that both the expertise scientists and the beginners in the field of the electronic properties of layered materials will find this book a valuable tool for their research work. Warm thanks are due to Prof. E. Mooser, General Editor of the series, for his constant and authoritative advice. * * * This book has been conceived as a tribute to Prof. Franco Bassani to whom the Italian tradition in the field of layer compounds, as well as in other fields of solid­ state physics, owes much. The authors of this review have all benefited at some time of their professional life from close cooperation with him. Istituto di Struttura della Materia, VINCENZO GRASSO Universitd di Messina IX V Grasso (ed.). Electronic Structure and Electronic Transitions in Layered Materials. ix.

Electronic Energy Bands.- 1. Introduction.- 2. Transition metal dichalcogenides.- 2.1. Dichalcogenides of the Group IVB transition metals.- 2.2. Dichalcogenides of the Group VB transition metals.- 2.3. Dichalcogenides of the Group VIB transition metals.- 3. Transition metal trichalcogenides.- 4. Monochalcogenides of the Group IIIA elements.- 5. Monochalcogenides of the Group IVA elements.- 6. Dichalcogenides of the Group IVA elements.- 7. Iodides of Group IIB and IVA elements.- 7.1. CdI2.- 7.2. PbI2 and SnI2.- 8. Graphite and hexagonal BN.- 9. Miscellaneous layered materials.- 9.1. Arsenic chancogenides.- 9.2. Di-and trihalides.- 9.3. V2O5.- 9.4. Black phosphorous.- 9.5. ZrCl, ZrBr, ScCl, PtTe.- 9.6. Li3N.- 9.7. CaGa2.- References.- Optical Properties in the Low Energy Range.- 1. Introduction.- 2. Group II dihalides.- 2.1. Cadmium iodide (CdI2).- 2.2. Mercuric iodide (HgI2).- 2.3. Cadmium chloride and bromide (CdCl2, CdBr2).- 3. Group IV halides.- 3.1. Lead iodide (PbI2).- 3.2. Lead bromide (PbBr2).- 4. Group V halides.- 4.1. Bismuth and antimony triiodides (BiI3, SbI3).- 5. Transition metal halides.- 5.1. Cobalt Chloride and bromide (CoCl2, CoBr2).- 5.2. Chromium trichloride and tribromide (CrCl3, CrBr3).- 5.3. Nickel chloride and bromide (NiCl2, NiBr2).- 6. Group III chalcogenides.- 6.1. Gallium selenide (GaSe).- 6.2. Gallium sulphide (GaS).- 6.3. Indium selenide (InSe).- 6.4. Gallium telluride (GaTe).- 6.5. Mixed crystals (GaSxSe,1-x, GaSexTe,1-x).- 7. Group IV dichalcogenides.- 7.1. Tin Disulphide (SnS2).- 7.2. Tin diselenide (SnSe2).- 7.3. Hafnium disulphide (HfS2).- 8. Transition metal dichalcogenides.- 8.1. Group IV transition metal dichalcogenides (TiS2, TiSe2, TiTe2, ZrS2, ZrSe2).- 8.2. Group V transition metal dichalcogenides (TaS2, TaSe2, NbTe2, NbSe2).- 8.3. Group VI transition metal dichalcogenides (WS2, WSe2, MoS2, MoTe2).- References.- Optical Properties in the High Energy Range.- 1. Introduction.- 2. Theoretical background.- 2.1. The dielectric function.- 2.2. Vertical transitions.- 2.3. The projected density of states.- 2.4. Near edge structures: local approach.- 2.5. Effects of the finite photon momentum.- 3. Connections between experiment and theory.- 4. Core excitons.- 4.1. Introductory considerations.- 4.2. Insulating compounds.- 4.3. Semiconducting compounds.- 4.4. BN and graphite.- 5. Vacuum ultraviolet spectra.- 5.1. The III–VI compounds.- 5.2. The IV–VI compounds.- 5.3. The V–VI compounds.- 5.4. The transition metal chalcogenides.- 5.5. Graphite and BN.- 5.6. Ternary semiconductors.- 5.7. Metal halides.- 6. X-Ray spectra.- 6.1. Transition metal dichalcogenides.- 6.2. The III–VI compounds.- 6.3. Metal halides.- 6.4. EXAFS spectroscopy.- References.- Photoemission.- 1. Introduction.- 1.1. The EDC mode of photoemission.- 1.2. The CFS photoemission mode and partial-yield spectroscopy.- 1.3. The CIS mode.- 1.4. Photo-polarized photoemission.- 1.5. Angle-resolved photoemisison: the band-mapping technique.- 2. III–VI compounds.- 2.1. EDC’s and CIS curves.- 2.2. Band mapping.- 2.3. The composition-dependent electronic structure of GaSxSe1-x solid.- 3. Group IV dichalcogenides: photoionization cross-section effects.- 3.1. Electronic structure of the valence and conduction bands of SnS2 and SnSe2.- 3.2. Core-level photoionization cross-section — extended fine structure.- 4. Group IV monochalcogenides.- 5. Layered halides: core excitonic effects.- 5.1. Electronic states: the important role of the lone-pair electrons.- 5.2. Core excitonic effects in PbI2 and BiI3.- 6. Transition-metal trichalcogenides and dichalcogenides.- 6.1. Transition-metal trichalcogenides.- 6.2. Transition-metal dichalcogenides.- 6.3. Photoemission investigations of phase transitions.- 7. Layer compounds of other families.- 7.1. Other kinds of binary and ternary layered chalcogenides.- 7.2. Graphite and intercalated graphite compounds.- 8. Final remarks.- References.- Plasmons in Layered Compounds.- 1. Outline.- 2. Plasmons in a uniaxial crystal: macroscopic theory.- 2.1. Electromagnetic equations.- 2.2. Normal modes.- 2.3. Damping of a light beam.- 2.4. Damping of fast electrons.- 3. Plasmon in selected layered crystals.- 3.1. Preliminaries.- 3.2. Insulators and semiconductors.- 3.3. Semimetals.- 3.4. Metals.- 4. Superlattice effects on a plasmon: the case of charge-density-waves.- 4.1. Scope of the section.- 4.2. Formulation.- 4.3. Plasmon shift due to the 3 X 3 charge density waves super-lattice of (2H) TaSe2.- 4.4. Plasmon damping caused by a charge density wave.- 5. Plasmons in electron—hole layered structures.- 5.1. Motivation.- 5.2. A model calculation.- 5.3. Results and discussions.- References.- Author Quotations Index.