Condensed Matter Physics 2014-15

*Prof Sir Richard Friend*

## Synopsis

**Periodic Systems: **Overview of crystal structures, the reciprocal lattice.

**Phonons: **Phonons as normal modes – classical and quantum picture. 1D monatomic chain, 1D diatomic chain, examples of phonons in 3D. Debye theory of heat capacity, thermal conductivity of insulators.

**Electrons in solids:**

Free electron model: Fermi-Dirac statistics, concept of Fermi level, electronic contribution to heat capacity. Bulk modulus of a nearly free electron metal. Electrical and thermal conductivity. Wiedemann-Franz law. Hall effect.

Nearly free electron model: Derivation of band structure by considering effect of periodic lattice on 1-D free electron model. Bloch’s theorem. Concept of effective mass. The difference between conductors, semiconductors and insulators explained by considering the band gap in 2D. Hole and electron conduction.

Doping of semiconductors, *p* and *n* types, *pn* junctions – diodes, LEDs and solar cells.

**BOOKS**

In general the course follows the treatment in *Solid State Physics*, J.R. Hook and H.E. Hall (2nd edition, Wiley, 1991).

*Introduction to Solid State Physics*, Charles Kittel (8th edition, Wiley, 2005) is highly recommended. (need not be the latest edition)

Other books, generally available in College libraries and may usefully be consulted:

*The Solid State*, Rosenberg H M (3rd edn OUP 1988)

*Solid State Physics*, Ashcroft N W and Mermin N D (Holt-Saunders 1976).