Trap-free insulators

Early Work of Mott. Poisson and Continuity Equations in a Trap-Free Insulator... 

The current in the trap-free insulators is obtained by solving the following Poisson and continuity equations,... 

This result is important since it shows that for finite (non-zero) Schottky barrier, i.e. P 0) < oo, and for large value of C, the current changes from the space charge limited current to the ohmic current. This result is similar to that given by Mott [36] for a trap-free insulator. Just before the ohmic region there is a transition region between the conventional power law and the ohmic region. 

In polymeric insulators, due to small concentrations and low mobility of free charges, the measured currents are very low, even at high electric fields. The dependence of steady-state current density jscLc on applied voltage y in the simplest form for the trap-free insulator (assuming that the ohmic electrodes are applied and there is no potential barrier for carrier injection) can be represented by Child s equation ... 

In a second approach to generate a CMOS inverter, OFETs with a PMMA insulator were utilized. For one of the OFETs the otherwise electron trap free PMMA dielectric was UV irradiated prior to the pentacene deposition [44]. 

Poly(o-aminophenol) was obtained by electropolymerization in an acidic aqueous solution [1099]. The relationship between electrode potential applied to the polymer film, current, conductivity, and concentration of free spins is displayed in Figure 77. The conductivity passes through a fairly narrow maximum, whereas the concentration of free spins (polarons) stays at high levels. Obviously the presence of free spins is not a suffieient precondition of electric conductivity, perhaps because the polarons are trapped between insulating sections of the polymer. 

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