impurity


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Related to impurity: impurity band, dissensions

impurity

Electronics a small quantity of an element added to a pure semiconductor crystal to control its electrical conductivity

impurity

[im′pyu̇r·əd·ē]
(science and technology)
An undesirable foreign material in a pure substance.
(solid-state physics)
A substance that, when diffused into semiconductor metal in small amounts, either provides free electrons to the metal or accepts electrons from it.
References in classic literature ?
It is a mirror which no stone can crack, whose quicksilver will never wear off, whose gilding Nature continually repairs; no storms, no dust, can dim its surface ever fresh; -- a mirror in which all impurity presented to it sinks, swept and dusted by the sun's hazy brush -- this the light dust-cloth -- which retains no breath that is breathed on it, but sends its own to float as clouds high above its surface, and be reflected in its bosom still.
The indignant thought that his declaration of love soiled her; that she could only be cleansed from the stain of its impurity by appealing to the honest and true; supported her for a time against her fears, and confirmed her in her hasty resolution.
Thus, now boasting, now despairing, in either fit a captive with the jail-rot upon him, and the impurity of his prison worn into the grain of his soul, he revealed his degenerate state to his affectionate child.
Both reduction of power consumption and chip size shrinkage require controlling channel impurity concentration and fining layout.
a) Diesel DIESELsymfona with the following specifications cetane number = 45 (MIN) KTHI (lower efficiency) = 9 800 - 10 400 kcal / KG, sulfur impurity content = 0.
By focusing on another type of impurity, researchers have now developed a simple method of determining growth rates along different directions in a quartz crystal.
The approach to controlling impurities in a given alloy consists of: * removing the impurity, if possible for
Water contaminants, including dissolved gases, are removed, metallic impurity sources are eliminated, and particle sources are greatly reduced, resulting in purity equal to or better than that created by burning oxygen and hydrogen.
The SIP identifies the quantity of impurity - the more impurity, the faster the color change.
According to AEC CEO Blaine Froats, "The results of the first purity test were most pleasing as only one unacceptable impurity existed at low levels.
The detection technology includes the introduction of new grades of methanizer flame ionization detection (FID) helium and hydrogen that consistently have less than 5 ppb of CO and CO2 -- a level of impurity that minimizes the bias and results in more accurate measurements of CO and CO2.
Theory predicts that wires of the same dimension and composition would show slightly different conductances, reflecting differences in the positions of the impurity atoms responsible for scattering the electron waves in each sample.