[10] When an electric field is applied strongly enough to draw the electrons into a beam, this may be referred to as a cathode ray, and is the basis of the cathode-ray tube display widely used in televisions and computer monitors until the 2000s.
[11] In semiconductors, which are the materials used to make electronic components like transistors and integrated circuits, two types of charge carrier are possible.
In p-type semiconductors, "effective particles" known as electron holes with positive charge move through the crystal lattice, producing an electric current.
In n-type semiconductors, electrons in the conduction band move through the crystal, resulting in an electric current.
[16] Minority carriers play an important role in bipolar transistors and solar cells.
[17] Their role in field-effect transistors (FETs) is a bit more complex: for example, a MOSFET has p-type and n-type regions.
It is similar to the carrier concentration in a metal and for the purposes of calculating currents or drift velocities can be used in the same way.
As yet, achieving superconductivity at room temperature remains challenging; it is still a field of ongoing research and experimentation.
Creating a superconductor that functions at ambient temperature would constitute an important technological break-through, which could potentially contribute to much higher energy efficiency in grid distribution of electricity.
Under exceptional circumstances, positrons, muons, anti-muons, taus and anti-taus may potentially also carry electric charge.
It might be possible to artificially create this type of current, or it might occur in nature during very short lapses of time.
It also occurs naturally in the cosmos, in the form of jets, nebula winds or cosmic filaments that carry charged particles.