Semiconductors, General Properties

The main characteristics of semiconducting materials are briefly reviewed. First, semiconductors are treated in the context of the one-electron band structure defining the differences with respect to metallic conductors. The same framework is then used to present basic notions, such as the effective mass, the mobility, intrinsic and doped materials, and donors and acceptors. The fundamental mechanism of rectification by p–n junctions and a short description of the main properties of selected group IV and III–V semiconducting materials – including direct-gap and indirect-gap cases – are then presented. Finally, a short introduction of the optical properties of semiconductors and their use in light emitting devices and photon detectors is presented.