excess electron

excess electron

[′ek‚ses i′lek‚trän]
(solid-state physics)
Electron introduced into a semiconductor by a donor impurity and available for conduction.
References in periodicals archive ?
The excess electron will flow to nearby sites, designated cathodic sites at which they will be consumed by oxidizing species from the corrosive solution.
The other source of static electric field is that which is a natural consequence of the excess electron charge close to the Earth's surface.
Implicit in the method is the requirement that the ordered part of the crystal structure has no excess electron density so that all excess electron density then necessarily resides in the voids.
The effective surface recombination velocity [S.sub.eff] is calculated using SRH and amphoteric center recombination models and plotted as a function of the excess electron concentration [DELTA]n(W) at the edge of the surface field region.
[[Ti.sup.4+]] represents the exposed neighbouring [Ti.sup.4+] at oxygen vacancy (1) and [[Ti.sup.3+]] represents the exposed Ti reduced by the excess electron (2) from O removal.
When the excess electron migrates into bulk water, a local hydrogen-bonding network around the I atom and the excess electron change drastically due to reorientation of water molecules; [I.sup.-] and an excess electron cloud are hydrophilic, whereas a neutral I atom is hydrophobic.
The most natural and Occam's-razor-consistent conclusion to be drawn from (19), however, is that the excess electron (or electrons) in the reflected current is (are) coming from the right (z > 0) of the step at z = 0 and proceeding in the negative z direction away from the step.
Free radicals are molecules that have one excess electron or one less electron, and they try to steal or give electrons to other molecules, thereby changing their chemical structure.
of Basel, Switzerland) here presents nine articles on important aspects of charge transfer processes in DNA, including the principles and mechanisms of photoinduced charge injection, transport, and trapping in DNA; sequence-dependent dynamics as the regulator of DNA-mediated charge transport; excess electron transfer in DNA probed with flavin- and thymine dimmer-modified oligonucleotides; dynamics of photoinitiated hole and electron injection in duplex DNA; spectroscopic investigation of charge transfer in DNA; and electron transfer and structural dynamics in DNA.
David Coker (Boston) discussed his work on the surface hopping trajectory approach to nonadiabatic dynamics of excess electron relaxation in fluids that exhibit localized equilibrium solvated electron states and to electron ejection and trapping in glassy matrices.
They survive in environments without oxygen, and they use nanowires to rid themselves of excess electrons in what can be considered their equivalent to breathing.
For example, a supply of electrons is required for capturing light energy, while turning nitrogen into ammonia releases excess electrons, which must be dissipated.