Conjugated Conducting PolymersHelmut Kiess This book reviews the current understanding of electronic, optical and magnetic properties of conjugated polymers in both the semiconducting and metallic states. It introduces in particular novel phenomena and concepts in these quasi one-dimensional materials that differ from the well-established concepts valid for crystalline semiconductors. After a brief introductory chapter, the second chapter presents basic theore tical concepts and treats in detail the various models for n-conjugated polymers and the computational methods required to derive observable quantities. Specific spatially localized structures, often referred to as solitons, polarons and bipolarons, result naturally from the interaction between n-electrons and lattice displacements. For a semi-quantitative understanding of the various measure ments, electron-electron interactions have to be incorporated in the models; this in turn makes the calculations rather complicated. The third chapter is devoted to the electrical properties of these materials. The high metallic conductivity achieved by doping gave rise to the expression conducting polymers, which is often used for such materials even when they are in their semiconducting or insulating state. Although conductivity is one of the most important features, the reader will learn how difficult it is to draw definite conclusions about the nature of the charge carriers and the microscopic transport mechanism solely from electrical measurements. Optical properties are discussed in the fourth chapter. |
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Results 1-5 of 43
Page 15
... configuration of the nuclei and the ( adiabatic ) dynamics around this ground state . The Born - Oppenheimer approximation is justified if the electronic motion is much more rapid than the relevant nuclear motions . Within the Born ...
... configuration of the nuclei and the ( adiabatic ) dynamics around this ground state . The Born - Oppenheimer approximation is justified if the electronic motion is much more rapid than the relevant nuclear motions . Within the Born ...
Page 20
... configuration of the ions , these are Bloch functions ( r ) from which we can derive , in principle , Wannier functions ( r ) centred around the Ith ( CH ) unit . Thus for this periodic reference configuration , we can write the ...
... configuration of the ions , these are Bloch functions ( r ) from which we can derive , in principle , Wannier functions ( r ) centred around the Ith ( CH ) unit . Thus for this periodic reference configuration , we can write the ...
Page 21
... configuration { R } , which is close to the actual configuration , and expands in powers of the ( assumed small ) displacements , u1 = R1 — R ° . If the ( small ) variations in the Wannier functions and in Veff ( r — r ' ) are neglected ...
... configuration { R } , which is close to the actual configuration , and expands in powers of the ( assumed small ) displacements , u1 = R1 — R ° . If the ( small ) variations in the Wannier functions and in Veff ( r — r ' ) are neglected ...
Page 22
... configuration ( u1 = R1 — R1 ) , - Vp ( r , { R } ) = Vp ( r , { R ° } ) + Σ avp TƏR ( r , { R ° } ) · u , + O ( u } ) . ( 2.10 ) Substituting this expression into ( 2.8a ) , we see that the one - electron term in ( 2.7 ) actually ...
... configuration ( u1 = R1 — R1 ) , - Vp ( r , { R } ) = Vp ( r , { R ° } ) + Σ avp TƏR ( r , { R ° } ) · u , + O ( u } ) . ( 2.10 ) Substituting this expression into ( 2.8a ) , we see that the one - electron term in ( 2.7 ) actually ...
Page 23
... configuration with a mirror plane through the carbon sites perpendicular to the chain axis , as in undimerized trans - polyacetylene . The gradient of the pseudo - potential is then odd under reflection through this mirror plane ...
... configuration with a mirror plane through the carbon sites perpendicular to the chain axis , as in undimerized trans - polyacetylene . The gradient of the pseudo - potential is then odd under reflection through this mirror plane ...
Contents
1 | |
7 | |
7 | 44 |
13 | 60 |
15 | 72 |
18 | 101 |
References | 114 |
28 | 115 |
Charge Transport in Polymers | 135 |
Theory and Experiment | 141 |
References | 171 |
References | 214 |
References | 297 |
Subject Index | 305 |
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Common terms and phrases
A.J. Heeger A.R. Bishop atoms Baeriswyl band band gap behaviour bipolarons bond alternation bond lengths calculations chain charged solitons Chem chemical shift cis-(CH conducting polymers configuration conjugated polymers correlation effects Coulomb interactions coupling Cryst D.K. Campbell defects dependence dimerization discussed dopant doping doping levels e-e interactions electron correlation electron spin electron-electron interactions electron-phonon ENDOR energy excitations exciton experimental finite polyenes frequency function Hamiltonian Hartree-Fock hopping Hubbard model Hückel inter-chain kink Kivelson lattice Lett linewidth magnetic Mazumdar metallic molecular molecules neutral solitons nonlinear nonlinear optical nuclear observed obtained one-dimensional optical absorption optical gap parameter peak Peierls Peierls-Hubbard model phonon Phys polarons polyacetylene polyenes polypyrrole polythiophene properties proton quantum quasi-particles Raman relaxation resonance Sect Solid State Commun spectra spectrum spin density SSH model susceptibility symmetry Synth temperature theoretical theory trans-(CH trans-polyacetylene transition triplet valence bond values Vardeny