What is "field effect"

n. The use of an electric field to control the conductivity of a channel in a semiconductor, as in FET.

Field effect may refer to: relative influence of electricity to the substrate within a given field.

• Field effect (semiconductor), the physical mechanism modulating the conductivity of a semiconductor using an applied voltage difference.
• Field effect (medicine): Field effects within medicine follow textbook physiology and rigid rules. The Immersed Boundary Method governs the macroscopic scale of the interface between living blood and tissue. Individual fields of influence are numerous.
  1. neoplasm (also referred to as "field defect", "field cancerization", and "field carcinogenesis"), a field of molecular and cellular changes in normal appearing tissue, which predispose to the development of cancer.
  2. ischemia Resource variability within Substrate by gradual or sudden degradation of either Blood or Electricity sources. Encyclopedic definitions of gating, pooling and draining Hydraulics extends the utility of understanding the myocardium as the underlying substrate.
• Wien effect, in electrolytes, an increase in ionic mobility or conductivity of electrolytes at very high gradient of electrical potential.

In physics, the field effect refers to the modulation of the electrical conductivity of a material by the application of an external electric field.

In a metal the electron density that responds to applied fields is so large that an external electric field can penetrate only a very short distance into the material. However, in a semiconductor the lower density of electrons (and possibly holes) that can respond to an applied field is sufficiently small that the field can penetrate quite far into the material. This field penetration alters the conductivity of the semiconductor near its surface, and is called the field effect. The field effect underlies the operation of the Schottky diode and of field-effect transistors, notably the MOSFET, the JFET and the MESFET.