What is the relation between scattering and mobility in solid state physics?

[struggling_student]

I came across the term scattering time in Simon's "The Oxford Solid State Physics".

Apparently it's supposed to be obvious because I can't find a definition anywhere but what is it? Why is so much stuff left undefined in solid state physics?

 

[jedishrfu]

This wiki article discusses it as well as other solid state terminology:

https://en.wikipedia.org/wiki/Elect...determining drift,its direction and/or energy.

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]