Threshold voltage separation

It contains parameters related to the solid-state (i.e., Ex) as well as to the chemical part(i.e., namL, jcq) of the sensor. Because the reference electrode is physically separate from the ISFET, its potential is not included in the threshold voltage. However, that choice is rather arbitrary. Whether the actual output follows (6.65) or (6.66) depends on the externally applied gate voltage Eg, which has nothing to do with the... 

Using naphthalenetetracarboxylic dianhydride as the semiconductor, changes in bulk conductivity, field-effect mobility, and threshold voltage were separately observed in response to exposure to water and oxygen [35, 36], Another more elaborate kind of pattern was produced by a virtual array of eleven different semiconductor OFET monitoring on-current in response to polar and nonpolar organic vapors [37]. Responses (0.8-0.3-fold reductions and 1.5-2-fold increases) were dis-... 

In summary, the 1-V characteristics of lightly doped quasi-ID PA nanofibers are non-ohmic and superlinear within the temperature interval 300-1.4 K. As temperature decreases the threshold voltage shifts to higher values with a weak influence of a magnetic field up to 7 T. We assume that at low temperatures such a doped polymer fiber can be considered as an array of small conducting regions separated by nanoscale... 

Fig. 6.4. Threshold voltage as a function of electrode separation for memory material TegiGejsSbjS using molybdenum electrodes. After Buckley (1972).

More detailed measurements of the dependences Uth f) in pure and doped MBBA at various temperatures (for sandwich cells) were performed [76, 109]. The results of these measurements are represented in Fig. 5.20. The threshold of the vortical motion was taken as the onset of the circular tion of the solid impurity particles in the electrode plane. The shape of the curves in Fig. 5.20 depends on the electrical conductivity. With a high electrical conductivity the curves have a plateau in the low-frequency region and a characteristic dependence I7th oc at frequencies above the critical frequency. At the transition point to the nematic phase the threshold voltage of the instability does not change. It is shown in [109] that the height of the low-frequency plateau is proportional to and at frequencies of u > 47r(j/e the threshold field does not depend on <7. Moreover, it does not depend on the thickness of the sample, i.e., on the separation between the electrodes. 

Figure 13.5 Threshold voltage dependence on the tip-surface separation, [a] Water, RH = 30%. [b] Ethanol. The inset shows the dependence of the maximum electric field on the tip-surface separation just before (solid line) and after (dotted line) the liquid bridge formation. The model uses a tip radius of 30 nm. (Data adapted from Ref 73.)...

In the ac case, space-charge separation perpendicular to the applied field is caused by the anisotropy in conductivity. 2,63 plied field produces a force upon the liquid crystal because of the space charge. This stimulus drags the fluid toward the walls. The cells walls impose boundary conditions that necessitate vortical flow of the fluid. The fluid shear torque aligns the director in the direction of the fluid flow, while the dielectric and elastic forces oppose the fluid deformation. At the threshold voltage, the fluid becomes unstable and the periodic distortion takes place. 

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