Electron thickness regimes

Figure 65 Unipolar (electron) current vs. electric field for a 0.1 cm-thick naphthalene single crystal provided with silver electrodes. Several different regimes can be distinguished (i) the low-field linear increase of the current (Ohmic regime) (ii) the SCLC in the presence of shallow traps (AE < kT) (iii) the trap-filled limit at FTFl and (iv) the SCLC with filled traps (no trapping). Adapted from Ref. 350a.

The drift mobility in this dispersive regime has an unusual electric field and thickness dependence. Fig. 3.13 shows the field dependence of the electron and hole mobility at different temperatures (Marshall et al. 1986, Nebel, Bauer, Gom and Lechner 1989). The electron drift... 

In the second part, theories of catalyst layers are presented. They account for the transport of feed gas, protons and electrons and rationalize the distribution of the rate of electrochemical reaction. A theoretically derived phase diagram suggests an optimum thickness of the layer, subject to the basic parameters and the target current regime. 

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