Semiconductors electrical properties, composition

The overview of the literature [284] should start with polymers and polymer-related materials like composites. However, for electrical properties a lot of pioneering experiments were done in the field of semiconductors, ce-... 

Chemical bonding and electrical conductivity provide five major categories of engineered materials metals, polymers, ceramics/glasses, composites, and semiconductors. The properties of these materials are dependent on atomic- and microscopic-scale stmcture, as well as on the way in which a given material is processed. Materials science enables the selection of the optimal material for a given application, see also Ceramics Glass Physical Chemistry Polymers, Synthetic Semiconductors. 

Electrochemical impedance spectroscopy provides a sensitive means for characterizing the structure and electrical properties of the surface-bound membranes. The results from impedance analysis are consistent with a single biomembrane-mimetic structure being assembled on metal and semiconductor electrode surfaces. The structures formed by detergent dialysis may consist of a hydrophobic alkyl layer as one leaflet of a bilayer and the lipid deposited by dialysis as the other. Proteins surrounded by a bound lipid layer may simultaneously incorporate into pores in the alkylsilane layer by hydrophobic interactions during deposition of the lipid layer. This model is further supported by the composition of the surface-bound membranes and by Fourier transform infrared analyses (9). 

If thermopassivation is a result of changes in composition of the corrosion layer, then the grid alloy composition will affect the semiconductor properties of the oxides in this layer through the dopants formed as a result of oxidation of the grid alloying additives. The latter s ions will modify the electrical properties of the oxides in the corrosion layer (Table 13.1) [5,6]. 

The term heterojunction in semiconductors science refers to a connection of layers of material with different electric properties, such as band gaps. The term bulk heterojunction has been introduced in organic semiconductors, and refers to a polymeric composite that is microscopically phase separated, e.g., by an interpenetrating network. These materials are characterized by a high interfacial area. 

By dispersing carbon black into POD-DPE, conductive composites can be obtained. The presence of carbon black enhances the thermal stability. The resistivity decreases continuously with an increase of pressure. Further, the composite shows a t5 ical semiconductor behavior, characterized by an increase of conductivity with temperature. The thermal and electrical properties and pressure sensitivity make this compound a good candidate for the application in manufacture of pressure sensors for high ambient temperatures. 

The energy band approximation constitutes a rigorous means for the understanding of the electronic behavior of semiconductors. However, in view of the complexity of the many electron systems the energy band approximation has been meaningfully or fully carried out for only a few simple systems. Furthermore, the band approximation does not lead to relationships concerning the dependence of electrical properties of materials on the chemical composition. It is... 

For numerous semiconductor compounds, experimental values of the heats of atomization (Hg) are not available. We have proposed [6] that an average heat of atomization (Hg) can be employed as a parameter of relative bond strength and consequently as the basis for correlatii the electrical properties of semiconductors and their chemical composition. For a compound... 

In the case of the nitrides and carbides the structures have some effect on the electric properties. For compounds that have an NaCl structure, the mononitrides and carbides are better metallic conductors than the metals themselves. Those that have zinc blende or Wiirtzite structures (SiC, AIN, InN) or other (SigNJ are useful semiconductors or insulators. Tungsten carbide when sintered with cobalt shows some catalytic activity in fuel cells. This hybrid composite is so hard and tough that it is widely used in drill bits for concrete drilling. 

During determination of dielectric constant (E = 3,5-5,0), tangent of angle of dielectric loss (tg5 = 0,02-0,03), specific volume electrical resistance (p = 10 - lO" Om-cm) we came to the conclusion that nitride and carbide of boron do not deteriorate the electrical properties of compositions and they are useful for pressurization of semiconductor instruments of high reliability. 

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