Carrier mobility converter
Convert carrier mobility between the CGS unit every datasheet uses and the SI one, and see the drift speed behind it.
That's about the same as electrons in silicon. In a field of 100 V/cm the carriers drift at about 1,400 m/s.
What it means
How fast do carriers move?
Mobility falls with temperature and with doping. Published figures are usually for lightly doped material at room temperature.
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Learn
Three things worth knowing
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1 m²/(V·s) = 10,000 cm²/(V·s)
The centimeter unit survives because silicon numbers come out as ordinary three- and four-digit figures in it.
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Drift, not speed
Electrons in a conductor rattle around at a million meters a second. The drift on top of that is a crawl — often millimeters a second — and it is the only part that carries current.
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Mobility is not conductivity
Conductivity is mobility times carrier concentration. Heavily doped silicon has poor mobility and excellent conductivity, because there are so many more carriers.
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Background
About carrier mobility
Mobility says how fast electrons or holes drift for a given electric field: velocity = mobility × field. Silicon electrons manage 1,400 cm²/(V·s); holes only 450, which is why n-channel transistors are faster.
Graphene reaches 200,000, which is a large part of why it excited everyone.