Search results
Results from the WOW.Com Content Network
Diffusion current is a current in a semiconductor caused by the diffusion of charge carriers (electrons and/or electron holes). This is the current which is due to the transport of charges occurring because of non-uniform concentration of charged particles in a semiconductor.
Drift current is the electric current caused by particles getting pulled by an electric field. The term is most commonly used in the context of electrons and holes in semiconductors, although the same concept also applies to metals, electrolytes, and so on.
This diffusion current is governed by Fick's law: = where: F is flux. D e is the diffusion coefficient or diffusivity; is the concentration gradient of electrons; The diffusion coefficient for a charge carrier is related to its mobility by the Einstein relation.
The saturation current (or scale current), more accurately the reverse saturation current, is the part of the reverse current in a semiconductor diode caused by diffusion of minority carriers from the neutral regions to the depletion region. This current is almost independent of the reverse voltage. [1]
The following image shows change in excess carriers being generated (green:electrons and purple:holes) with increasing light intensity (generation rate /cm 3) at the center of an intrinsic semiconductor bar. Electrons have higher diffusion constant than holes leading to fewer excess electrons at the center as compared to holes.
This process generates current, referred to as diffusion current. Diffusion current can also be described by Fick's first law = /, where J is the diffusion current density (amount of substance) per unit area per unit time, n (for ideal mixtures) is the electron density, x is the position [length].
Hannah Kobayashi's family says she was "found safe" on Wednesday, Dec. 11, about a month after she walked into Mexico and vanished in what police have called a voluntary disappearance that made ...
In semiconductor physics, the depletion region, also called depletion layer, depletion zone, junction region, space charge region, or space charge layer, is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have diffused away, or been forced away by an electric field.