Characteristic curves current/voltage

Mains voltage influences. The given tolerances of the characteristic curves (constant voltage + 2%, constant current + 2%) have to be guaranteed for mains fluctuations of + 10% and frequency fluctuations of +2%. 

The device structures, operations of OFETs, and estimation of the FET characteristics from current-voltage curves have been summarized previously [2]. The important parameters to evaluate the quality of an OFET are carrier mobility /d), on/off ratio, and threshold voltage 8 performance of the transistor... 

Figure 43. Calculated current—voltage characteristics and power density curve of electrolyte-supported co-flow SOFC at an operating temperature of 1000 °C and anode and cathode stoichiometry of 1.5 and 2.0 at 0.4 A/cm, respectively.

The rotating disc electrode is constructed from a solid material, usually glassy carbon, platinum or gold. It is rotated at constant speed to maintain the hydrodynamic characteristics of the electrode-solution interface. The counter electrode and reference electrode are both stationary. A slow linear potential sweep is applied and the current response registered. Both oxidation and reduction processes can be examined. The curve of current response versus electrode potential is equivalent to a polarographic wave. The plateau current is proportional to substrate concentration and also depends on the rotation speed, which governs the substrate mass transport coefficient. The current-voltage response for a reversible process follows Equation 1.17. For an irreversible process this follows Equation 1.18 where the mass transfer coefficient is proportional to the square root of the disc rotation speed. 

Fig. 11 (a) Molecular orbital location in a C o based molecular rectifier, (b) Typical current-voltage characteristics recorded for HgATFPP/Cgo/SiCn ) structure (schematic shown in the upper inset). The lower inset shows a symmetric I-V curve recorded for the Hg/C6o/Si(n ) structure. (Reprinted with permission from [99])... 

Fig. 11.4. Logarithmic amplifier, (a) Schematic of a logarithmic amplifier. A diode is used as the feedback element in a current amplifier. The current-voltage characteristics are exponential. The output voltage is then proportional to the logarithm of the input current, (b) The transfer curve of a typical logarithmic amplifier, AD757N from Analog Devices. The reference current is internally set to be 10 p,A. It is accurate up to six decades.

An STM probe has been used to isolate individual MS (M = Cd, Pb) particles and to measure electronic phenomena (55,56,81). The MS films were prepared either by exposure of metal ion/fatty acid films to H2S (55,56) or by transfer of a compressed DDAB-complexed CdS monolayer (81). All the films were transferred onto highly oriented pyrolytic graphite (HOPG) for the STM measurements. A junction was created at an individual CdS particle with the STM tip as one electrode and the graphite as the other, and the current/voltage characteristics of the panicles were measured. For the particle prepared in the fatty acid films the I/V curves exhibit step-like features characteristic of monoelectron phenomena. In the case of the DDAB-coated CdS particles the I/V measurements demonstrated n-type semiconductor behavior. The absence of steps in this system is probably a reflection of the larger size of the particles in the DDAB films (8 nm by AFM) compared to the 2-nm particle size typically found for MS particles formed in fatty acid films. 

Thus, the displacement of the characteristic current voltage curves along the voltage axis represents the required C.P.D., Va a (Fig. 15). 

A similar mechanism could operate in the reduction of oxygen on chelate catalysts, as in the organic cathodes with air regeneration described by Alt, Binder, Kohling and Sandstede 13-40>. These cathodes contain a reversible insoluble quinone/hydroquinone system. The quinone, which is electrochemically reducible, can be obtained either by electrochemical oxidation or by purely chemical oxidation with H2O2 or oxygen (air). A cathodic current is observed in these systems only at potentials below the redox potential, and unusually hard current/ voltage characteristic curves are obtained. 

The current/voltage characteristic curves for the reduction of 2 on chelate catalysts mostly show a Tafel region with a slope of about 60 mV. This could... 

Fig. 7. Theoretical current-voltage characteristics of thick carrier membranes with different charge concentrations c = Z/CISn. The values for c are arbitrary and increase from curve A to D (for details see [55]).

Fig. 8. Current-voltage characteristics of two hypothetical devices of identical physical size. The gallium arsenide curve rises faster and reaches peak velocity faster than the silicon. This means that the group III-V (13-15) electrons produce significantly faster operating times in microchips. (AT T Technology)...

In Figure 2 we show the equivalent results with a reasonably effective stabilizing agent, ferrocyanide, present. In this figure we show results with HF present (no oxide) for comparison as curve (d). The first cycle of a freshly etched electrode in the 0,1 M potassium ferrocyanide/water solution is indicated in the current/voltage characteristics as curve (a). Now in curve... 

The complete current-voltage characteristics of the sensor can be derived from the similar consideration that was used for derivation of the i-E curve for liquid electrolytes. Because the potentials at each electrode are reversible, their difference can be expressed by the Nernst equation for the concentration of oxygen at the anode Co(0) and at the cathode Co (A). The current flowing through the layer generates a voltage drop iRb, where Rb is the bulk resistance of the ZrC>2 layer. 

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