An informal and highly accessible writing style, a simple treatment of mathematics, and clear guide to applications, have made this book a classic text in electrical and electronic engineering. Students will find it both readable and comprehensive. The fundamental ideas relevant to the understanding of the electrical properties of materials are emphasized; in addition, topics are selected in order to explain the operation of devices having applications (or possible future applications) in engineering. The mathematics, kept deliberately to a minimum, is well within the grasp of a second-year student. This is achieved by choosing the simplest model that can display the essential properties of a phenomenon, and then examining the difference between the ideal and the actual behaviour. This new edition features many subjects which have reached maturity in the last 5 years, like organic semiconductors and artificial materials. The largest addition is to the treatment of light emitting diodes which are rapidly replacing classical lighting sources. There are also a number of new devices discussed including nanotube transistors, single electron transistors, magnetic tunnel junctions, quantum cascade lasers, and new ferroelectric and superconducting memories. The whole text is designed as an undergraduate course. However most individual sections are self contained and can be used as background reading in graduate courses, and for interested persons who want to explore advances in microelectronics, lasers, nanotechnology and several other topics that impinge on modern life. Online Resource Centre features: illustrations from the text available to download; and solutions manual, giving worked solutions to the problems in the book, available to download in PDF format.