Electron mobility

In physics, electron mobility (or simply, mobility), is used to describe the relation between drift velocity of electrons or holes in a solid material or electrons/ions in a gas, and an applied electric field. The drift velocity is directly related to the electric field as follows,

Related Topics:
Physics - Drift velocity - Electron - Hole - Ions - Electric field

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:v_d = mu E,

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where μ is the mobility.

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In metric units, mobility is normally measured in cm2/(V·s). Since mobility is a strong function of impurities in a materials as well as temperature, it is difficult to provide any values of mobility here for common materials. Mobility is also different for electrons and holes in a semiconductor. When one charge carrier is dominant the conductivity of a semiconductor is directly proportional to the mobility of the dominant carrier.

Related Topics:
Metric - Cm - V - S - Semiconductor - Conductivity

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Typical electron mobility for GaAs at room temperature is 2000 cm2/(V·s).

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In approximation the mobility can be written as a combination of influences from lattice vibrations (phonons) and from impurities by following equation:

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:mu = rac{1}{rac{1}{mu_{ m lattice}}+rac{1}{mu_{ m impurities}}}.

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