Occurs when the conduction band and the valence band become a function
of position because of an electric field that exists inside a material.
The result is a variation of Ec and Ev
with position in the energy band diagram.
Current density:
Current is the charge per unit time crossing an arbitrarily chosen plane
of observation oriented normal to the direction of current flow. Current
density, J, is the current per unit area (J=I/A).
Diffusion:
The angular redistribution of radiation by a scattering, reflecting or
refracting system, ideally producing an isotropic distribution of intensity.
The gradual mixing of the molecules of two or more substances, as a result
of random thermal motion.
Drift:
To be carried along by or as by currents of air or water. To vary from
or oscillate randomly about a fixed setting, position, or mode of operation.
To move leisurely or sporadically from place to place.
Equilibrium:
A condition in which all acting influences are canceled by others, resulting
in a stable, balanced, or unchanging system. The condition of a system
in which the resultant of all acting forces is zero and the sum of all
torques about any axis is zero. The state of a reaction in which its forward
and reverse reactions occur at equal rates so that the concentration of
the reactants does not change with time.
Generation:
The act or process of generating, i.e. origination, production or procreation.
We will use it as the process whereby electrons and holes are created.
Lifetime:
The period of time during which an individual is alive. The period of time
during which an object, property, process, or phenomenon exists or functions.
Mobility:
Capable of moving or of being moved from place to place. Moving quickly
from one place to another; flowing freely.
Perturbation:
To disrupt greatly; to agitate. Variation in a designated orbit, as of
an electron or planet, resulting from the influence of one or more external
bodies.
Radiation:
The act or process of radiating. The emission and propagation of waves
or particles. The propagating waves or particles, such as light, sound,
radiant heat, or particles, emitted by radioactivity.
Recombination:
We will use it in the context of it being the process whereby electrons
and holes (carriers) are annihilated, or destroyed.
Resistivity:
The capacity for or tendency toward resistance. The resistance per unit
length of a substance with uniform cross-section. Resistance is the opposition
to electric current characteristic of a medium, substance, or circuit element.
Scattering:
The act or process of separation or dispersing. The dispersal of a beam
of particles or of radiation into a range of directions resulting from
physical interactions.
Thermal motion:
Motion due to temperature. Thermal is of, pertaining to, using, producing,
or caused by heat.