Search results
Results From The WOW.Com Content Network
Then the electron mobility μ is defined as =. Electron mobility is almost always specified in units of cm 2 /(V⋅s). This is different from the SI unit of mobility, m 2 /(V⋅s). They are related by 1 m 2 /(V⋅s) = 10 4 cm 2 /(V⋅s). Conductivity is proportional to the product of mobility and carrier concentration. For example, the same ...
The formula for evaluating the drift velocity of charge carriers in a material of constant cross-sectional area is given by: [1] =, where u is the drift velocity of electrons, j is the current density flowing through the material, n is the charge-carrier number density, and q is the charge on the charge-carrier.
The particles acquire an electrical mobility and are driven by the field to a collecting electrode. Instruments exist which select particles with a narrow range of electrical mobility, or particles with electrical mobility larger than a predefined value. [3] The former are generally referred to as "differential mobility analyzers".
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Help; Learn to edit; Community portal; Recent changes; Upload file
where D is the diffusion coefficient for the electron in the considered medium, n is the number of electrons per unit volume (i.e. number density), q is the magnitude of charge of an electron, μ is electron mobility in the medium, and E = −dΦ/dx (Φ potential difference) is the electric field as the potential gradient of the electric potential.
The drift velocity deals with the average velocity of a particle, such as an electron, due to an electric field. In general, an electron will propagate randomly in a conductor at the Fermi velocity. [5] Free electrons in a conductor follow a random path. Without the presence of an electric field, the electrons have no net velocity.
The proportionality constant is known as mobility of the carrier, which is a material property. A good conductor would have a high mobility value for its charge carrier, which means higher velocity, and consequently higher current values for a given electric field strength. There is a limit though to this process and at some high field value, a ...
The drift velocity, and resulting current, is characterized by the mobility; for details, see electron mobility (for solids) or electrical mobility (for a more general discussion). See drift–diffusion equation for the way that the drift current, diffusion current, and carrier generation and recombination are combined into a single equation.