Mott variable-range hopping

Table 12.4. Parameters obtained from the least-squares fitting of the Mott variable range hopping model to the data shown in Figure 12.4 (see text for parameter definitions and film designations)...

First, at low dopant concentrations, both PPY and PAc act as insulators. At a relatively high temperature, electronic transport can be described by Mott variable-range-hopping (VRH) model. Resistivity is a function of temperature that follows ... 

It is found that the Mott variable-range hopping law often holds at intermediate temperatures and the Efros-Shklovskii variable-range hopping law at lower temperatures. 

The charge transport properties in the direction of free-carrier motion in a restricted-dimensional system have inportant consequences for the magnetotransport effects. This is treated in Sect. 5.3.4. For disordered systems, when the Mott variable-range hopping mechanism [3.58] dominates the conductivity, the temperature scaling law depends on the dimensionality the 3-D conductivity <73-0 varies with temperature following the law log (T3.D a T, whereas the 2-D conductivity varies as log (T2-D The transition from 3-D to 2-D behav-... 

According to the Mott variable-range hopping (MVRH) model for conduction in solids, the temperature (T) dependence of electronic conductivity (. ) is given by... 

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