Solid-State and Materials Chemistry

50 lessons, pages 3881–3930.

  1. From Molecules to Extended Solids — Why solids need a different electronic description from isolated molecules
  2. Bravais Lattices and Space Groups — The 14 lattices, symmetry operations and how crystal structures are classified
  3. The Reciprocal Lattice — Reciprocal vectors, lattice planes and the link to diffraction
  4. Bragg's Law and the Laue Condition — Two equivalent pictures of diffraction and structure factors
  5. Free-Electron Model of Metals — Electrons in a box, Fermi energy and Fermi sphere
  6. Density of States — Counting electronic states per unit energy in one, two and three dimensions
  7. Fermi–Dirac Statistics in Solids — Occupation of states, the Fermi level and temperature smearing
  8. Bloch's Theorem — Wavefunctions in a periodic potential and the crystal momentum k
  9. The Brillouin Zone — First zone, zone boundaries and high-symmetry points
  10. Nearly Free Electron Model and Band Gaps — How Bragg reflection at zone boundaries opens energy gaps
  11. Tight-Binding Model: Bands from Orbitals — LCAO chains, band width and overlap integrals
  12. Band Structure Diagrams — Reading E–k plots, band dispersion and effective mass
  13. Metals, Semiconductors and Insulators — Band filling, gap size and the classification of solids
  14. Band Theory of Main-Group Solids — sp hybrid bands in diamond, silicon and tin, and trends down Group 14
  15. Bands in Transition-Metal Compounds — d bands, narrow bands and the Mott insulator idea
  16. Peierls Distortion and Low-Dimensional Solids — Why one-dimensional metals distort and open a gap
  17. Band Theory: Checkpoint Review — Consolidating free-electron, Bloch and tight-binding pictures
  18. Thermodynamics of Point Defects — Why defects are always present above absolute zero; enthalpy versus configurational entropy
  19. Kröger–Vink Notation — Writing defects, effective charges and balanced defect equations
  20. Intrinsic Defect Equilibria — Schottky and Frenkel equilibrium constants and defect concentrations
  21. Extrinsic Defects and Aliovalent Doping — Charge compensation by vacancies, interstitials or electronic defects
  22. Non-Stoichiometry and Oxygen Partial Pressure — Metal-deficient and oxygen-deficient oxides; Brouwer diagrams
  23. Colour Centres in Crystals — F-centres, trapped electrons and coloured alkali halides
  24. Line Defects: Dislocations — Edge and screw dislocations, Burgers vectors and slip
  25. Planar and Volume Defects — Grain boundaries, stacking faults, twins and voids
  26. Diffusion in Solids — Vacancy and interstitial mechanisms, Fick's laws and Arrhenius behaviour
  27. Solid Electrolytes and Ionic Conduction — Fast-ion conductors, stabilised zirconia and defect-mediated conductivity
  28. Defects: Checkpoint Review — Linking defect chemistry to transport, colour and mechanical properties
  29. Intrinsic Semiconductors — Electrons, holes and thermal generation across the gap
  30. Carrier Concentration and the Law of Mass Action — The product np = nᵢ² and its temperature dependence
  31. Donor and Acceptor Doping — Shallow levels, ionisation energies and n-type versus p-type material
  32. The Fermi Level in Doped Semiconductors — How doping and temperature shift the Fermi level
  33. Carrier Mobility and Conductivity — Drift, scattering mechanisms and σ = neμ
  34. Direct and Indirect Band Gaps — Momentum conservation, phonon-assisted transitions and light emission
  35. Optical Absorption and Band-Gap Measurement — Absorption edges, Tauc analysis and colour of semiconductors
  36. The p–n Junction — Depletion region, built-in potential and band bending
  37. Diodes and Rectification — Forward and reverse bias and the diode equation
  38. Light-Emitting Diodes — Radiative recombination and tuning colour with composition
  39. Photovoltaic Cells — Charge separation, efficiency limits and solar-cell materials
  40. Compound Semiconductors — III–V and II–VI materials, alloys and band-gap engineering
  41. Metal–Semiconductor Contacts — Work functions, Schottky barriers and ohmic contacts
  42. Semiconductor Electrodes and Photocatalysis — Band edges in solution, TiO₂ and water splitting
  43. Quantum Dots and Nanostructured Semiconductors — Quantum confinement and size-dependent band gaps
  44. Transparent Conducting Oxides — Wide gaps with high carrier density: ITO and doped ZnO
  45. Superconductors — Zero resistance, the Meissner effect and cuprate chemistry
  46. Magnetic Materials and Exchange — Ferro-, antiferro- and ferrimagnetism and superexchange in oxides
  47. Synthesis of Solid-State Materials — Ceramic, sol–gel, hydrothermal and vapour-deposition routes in outline
  48. Characterising Solids — Powder XRD, electron microscopy and spectroscopic probes of structure
  49. Designing Functional Materials — Linking structure, bonding, defects and bands to target properties
  50. Solid-State and Materials Chemistry: Unit Review — Band theory, defects and semiconductors brought together