Charge carriers transference

The existence of two types of mobile charge carriers in semiconductors enables us to distinguish between a majority charge carrier transferred from the electrode into the electrolyte and a minority charge carrier injected from the electrolyte into the electrode. Minority carrier injection causes significant reverse currents, but may also contribute to the total current under forward conditions. 

Dispersive transport in PVC was investigated. The results of Pfister and Griffits obtained by the transit method are shown in Fig. 6. The hole current forms at temperatures > 400 K clearly show a bend corresponding to the transit time of the holes. At lower temperature the bend is not seen and transit time definition needs special methods. The pulse form shows the broad expansion during transition to the opposite electrodes. This expansion corresponds to the dispersive transport [15]. The super-linear dependence of the transit time versus sample thickness did not hold for pure PVC. This is in disagreement with the Scher-Montroll model. There are a lot of reasons for the discrepancy. One reason may be the influence of the system dimensions. It is quite possible that polymer chains define dimension limits on charge carrier transfer. 

Photosensitivity in a PVC-Se two layer Systran is equal to the Se photosensitivity in the strong absorption region [13]. The experimental data are presented in Fig. 13. Strong dependence of the photoresponse on the electric field strength was established. For n-Se and p-Se it was explained by the dependence of the quantum yield and charge carrier transfer from the electric field respectively. 

The localization radius Rc was equal to 0.1 nm for lexan with TP A, 0.154 nm with IPC, and 0.1 nm for PVC with TP A. The strong exponential dependence of the mobility proves the charge carrier transfer between localized states, connected with doping molecules. 

A. Cesnys, G. Juska and E. Montrimas, Charge Carrier Transfer at High Electric Fields in Noncrystalline Semiconductors... 

In the presence of a redox system dissolved in the electrolyte, as long as there exists an energy difference between the Fermi level of the semiconductor and the redox couple, to reach the equilibrium conditions charge-carrier transfer occurs across the semiconductor-liquid interface via the energy bands, i.e., the conduction or valence band of the semiconductor. At the equilibrium point, the Fermi level of the redox... 

Fig. 16.5 Charge-carrier transfer at large (left) and small (right) semiconductor particles in the presence of an electron donor D and an acceptor A [Copyright Wiley-VCH Verlag GmbH Co. KGaA. Reproduced with permission from Memming (2001)]...

SCHATZ, T., COOK, A. R., MEISEL, D., Charge Carrier Transfer Across the Silica Nanoparticle / Water Interface , J. Phys. Chem. 1998, 102, 7225-7230. 

In organic molecular crysrals the charge-carrier transfer integrals w are sensitive to the changes in intermolecular distance. The relation between w and the lattice displacements can be linearized and written in the form... 

To ensure optimal charge carrier transfer at the interface between the semiconductor and the substrate, it is essential to form a low-loss electronic contact (e.g., an ohmic or tunnel junction contact). An ohmic contact, as the name implies, follows Ohm s... 

The charge carrier transfer process in TiOj/BiaMoOg composites is as follows ... 

Our initial objective was to prepare organic polymeric systems which may be modified to electrically conducting materials. The approach was to obtain the butadiyne polymer in a thin film form by taking advantage of the synthetic procedure, characterization techniques and struc re-property insight that have been developed for polyacetylene. The formation of a partially crosslinked polyvinylene system that may reduce or eliminate the requirement of charge carrier transfer by intermolecular chain contact was envisioned (Eq. 2). 

Tyczkowski, J. (2010). Charge Carrier Transfer A Neglected Process in Chemical Engineering. Ind, Eng, Chem, Res, Vol. 49, pp. 9565-9579 Tyczkowski, J. (2011). New Materials for Innovative Energy Systems Produced by Cold Plasma Technique. Fund Mater, Lett, in press... 

Co -", Ni "", Cu -", and Zn ) [73], GR-Pd-CdS [76], and hierarchical CdS-ZnO-GR hybrids [108]. It is found that their photoactivities for reduction of nitro compounds to amino compounds with ammonium formate (HCOONH4) for hole scavenger in N2 atmosphere (Scheme 8.11) under visible light irradiation are all remarkably enhanced as compared to the blank semiconductors [73,100-102,106, 107]. It has been concluded that the selective reduction efficiency can be driven by appropriate introduction of GR into the matrix of pure semiconductor, which can boost the transfer and prolong the lifetime of the electrons photoexcited from the semiconductor due to the tighter connection between GR and the semiconductor, as well as the optimization of the atomic charge carrier transfer pathway across the interface between GR and the semiconductor. 

When the temperature inaeases, the probability of charge carrier transfer to the nearest neighbor increases, in spite of the energy difference, as shown in Figure 5(b). In such a case a more appropriate description of charge transport is offered by the Miller-Abrahams model descrihed in Section 2.33.2.3.2.2. 

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