The general formalisms of the charge carrier transport properties in semiconductors were presented with an emphasis on the basic concepts that allow one to investigate nanoscale materials and devices. The aim of presenting the formalisms here was to show the reader in a broader sense how the bulk materials are treated and to show the limitations of a classical treatment of the subject. Various characteristic lengths, including the de Broglie wavelength, and time scales of several physical processes were presented. These characteristic lengths show the transport regimes in bulk, mesoscopic, and low-dimensional semiconductor systems.

Hall-effect, quantum Hall-effect, and Shubnikov-de Haas measurements are widely used to investigate the transport properties in bulk and heterojunction semiconductors. These experimental techniques were discussed, and the basic formalisms to interpret the data were presented.

The discussion in this chapter started with the charge carrier transport in bulk materials, where the drift and diffusion current densities are dominant. The phenomenon of hot electron was briefly discussed, and the Gunn diode was presented as an example of the hot electron transport in bulk semiconductors. The Gunn diode operates in the gigahertz region where a negative differential resistance is observed at high electric fields in compound semiconductors, such as GaAs and InP. The negative differential resistance is the primary cause of the instability in the device, which leads Gunn oscillations with frequencies in the microwave region. In addition to drift and diffusion current densities, the generation and recombination processes in semiconductor materials were discussed. The continuity equation,...