Relation between scattering and mobility[edit]
Recall that by definition, mobility is dependent on the drift velocity. The main factor determining drift velocity (other than effective mass) is scattering time, i.e. how long the carrier is ballistically accelerated by the electric field until it scatters (collides) with something that changes its direction and/or energy. The most important sources of scattering in typical semiconductor materials, discussed below, are ionized impurity scattering and acoustic phonon scattering (also called lattice scattering). In some cases other sources of scattering may be important, such as neutral impurity scattering, optical phonon scattering, surface scattering, and defect scattering.[12]
Scattering time refers to the amount of time it takes for a particle or wave to be scattered from its original path due to interactions with other particles or obstacles in its environment.
Scattering time can be measured by observing the change in direction or velocity of the particle or wave over a period of time. It can also be calculated using mathematical models and equations.
The scattering time of a particle or wave can be influenced by several factors, including the density and composition of the medium it is traveling through, the size and shape of the particles or obstacles it encounters, and the energy of the particle or wave.
Scattering time is an important concept in physics as it helps us understand the behavior of particles and waves in different environments. It is also used in various fields such as material science, astrophysics, and quantum mechanics to study the properties of matter and energy.
Scattering time is closely related to other concepts such as diffusion, reflection, and refraction. It is also connected to the principles of conservation of energy and momentum, as well as the laws of thermodynamics.