Semiconductor, conductivity

In order to obtain appreciable conductivities, semiconductors must be doped witli small amounts of selected impurities. It is possible to switch tire doping type from n to p type, or vice versa, eitlier during tire growtli of a crystal or by tire selective introduction of impurities after tire growtli. The boundary region between tire p type and n type regions is... 

Eor metals, S generally varies between about 0 and 40 ]lV/K low conductivity semiconductors and insulators have values of S up to 1000 ]lV/K and higher. 

In this chapter nonlinear piezoelectric and dielectric behavior shock-induced electrical conductance semiconductors elastic physical properties. 

The scheme of the element is shown in Fig. 4.16. In order to increase variation of electric conductivity semiconductor film was deposited in the center of the plate, whereas activator was deposited at the plate edges at above specified distances through a mask. All stages of preparation were conducted in high vacuum ( 10" Torr). Sensitivity of such sensors to adsorption of hydrogen atoms at room at lower temperatures was about 10 - 10 at/cm, which corresponds to surface coverage of only 10-8 10-7% ( )... 

The size of the bandgap can vary from a fraction of an eV (in the IR region of the spectrum) to ca. 4 eV or more (wide-bandgap semiconductors). The upper limit is somewhat arbitrary a substance commonly thought of as an insulator such as diamond has a large bandgap of 5.5 eV, but it can nevertheless be doped with elements such as B, N, or P to become an electrically-conducting semiconductor. 

In the sense of electric conductivity, semiconductors are close to conductors but have very few free electrons. When electric resistance of metals increases with temperature, the semiconductor resistance decreases with temperature. Some of the electrons that are not free at normal temperature... 

A high electrical conductivity (semiconductor up to semimetallic conductivity)... 

Material science interest focuses on potential applications of its specific electronic and band structure. Metal-like conductivities, semiconductor properties, photoconductivity and the nonlinear optical features of URPAC samples suggest devices for electromagnetic shielding, energy storage, microelectronics, optoelectronic and optooptical communication or optical computing. 

So far, in reported SECM studies the rate constant and the transfer coefficient have been sufficient to describe the experimental results. However, the ohmic resistance of solids may lead to potential gradients inside bulk materials, which have not been dealt with up to now. This effect has to be taken into account, especially at poorly conducting semiconductors and thin films on insulators. 

Tin dioxide is characterized, just like zirconia, by the presence of oxygen vacancies. However, its electrical properties lead to it being sorted in the electronic-conduction semiconductor category. 

Bonding in Solids Metals, Insulators, and Semiconductors Models of Metallic Bonding Band Theory and Conductivity Semiconductors... 

Figure2.2. Conductivityin semiconductors. Le/t Intrinsic conductivity (/-semiconductors). Right p- and M-semiconductor function with doping...

A typical doping curve for PA is shown in Figure 3. These data are taken from the work of Park et al.(48) The results are characteristic of the doping of PA in that they show a S-curve shape with a precipitous rise in conductivity (semiconductor-to-metal transition ) at a doping level of about 2 to 4%. (More... 

The observational efficiency advantage of F.T. spectroscopy presumes that detector noise is constant regardless of whether the detector is employed in a grating or F.T. spectrometer. This is true only for low quality detectors. Most high quality detectors, from bolometers in the far I.R. to photo-conductive semiconductor detectors in the mid I.R., near I.R., and visible region, can achieve the "background limited mode", on F.T. spectrometers. In that case it becomes crucial to determine whether the radiation intercepted by the detector is radiation containing spectral information of interest or not. 

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