What is electrical mobility?
Electrical (carrier) mobility describes how quickly a charged particle, like an electron or ion, moves through a material in response to an applied electric field. It’s a key property in semiconductor design, since higher mobility generally means faster, more efficient devices.
The formula
Mobility is calculated as μ = vd ÷ E, where vd is the carrier’s drift velocity (average velocity gained from the field, distinct from random thermal motion) and E is the electric field strength. The SI unit is m2/(V·s), though cm2/(V·s) is more commonly used in semiconductor literature.
Mobility is generally treated as constant only at low-to-moderate field strengths; at very high fields, carrier velocity can saturate and no longer increase linearly with field strength. This calculator is for general physics and semiconductor education.