The course covers the physics relevant for the manufacture and operation of electronic and optoelectronic devices which have revolutionised civilian and military technology. In particular it discusses crystal structure, and its determination by x-ray diffraction and electron microscopy, as an introduction to the concept of wave-particle duality. Other topics include the time-independent Schroedinger equation and the quantum-mechanical description of electrons, the Pauli Exclusion Principle, an introduction to the concept of band gaps, factors influencing the speed of electronic switching, and the absorption and emission of photons. The physical concepts are applied to a selection of the following topics: high-speed amplifiers and modulation doping, band-gap engineering, semiconductor lasers and light-emitting diodes, solar cells, thermoelectric devices, and piezoelectric transducers.