Hall effect measurements

Temperature dependent Hall effect measurements have also been carried out in the temperature range 30 to 260 K on a K3C60 thin film [116]. For three... 

Kennedy and Benedick [67K02, 68K03] were successful in carrying out difficult Hall effect measurements in germanium samples explosively loaded at the upper end of the elastic range. Nevertheless, the measurements did not provide sufficient information to develop a physical interpretation. 

Several additional conclusions concerning the nature of the chemisorbed layer can be drawn from the Hall effect measurements (33, 34) The chemisorbed species, together with the surface metal atoms, represent complexes analogical to the ordinary chemical compounds and, consequently, one might expect that the metal atoms involved in these complexes will contribute to lesser extent or not at all to the bulk properties of the metal. Then we should speak about the demetallized surface layer (41). When the Hall voltage was measured as a function of the evaporated film thickness... 

Combined resistivity and Hall-effect measurements provided the first... 

For depth inhomogeneities in the free electron concentration n x) and electron mobility the Hall-effect measurement yields an effective... 

To eliminate the above uncertainties in the interpretation of the transport data, Hall-effect measurements were combined with layer removal on homogeneously doped n-type layers (Johnson and Herring, 1988a). The... 

In the study by Johnson et al. (1986) it was shown by Hall effect measurements that the sheet carrier density was decreased and the mobility was increased for a thin w-type layer following exposure to a hydrogen plasma at 150°C. To explain the mobility increase it was argued that donor-H complexes were formed and that the concentration of ionized scattering centers was thereby decreased. On the basis of semiempirical calculations, a structural model was suggested for the donor-H complex in... 

This same equation is, of course, also used to rationalise the general electronic behaviour of metals, semiconductors and insulators. The quantitative application of Eqn (2.1) is handicapped for ionic conductors by the great difficulty in obtaining independent estimates of c,- and u,-. Hall effect measurements can be used with electronic conductors to provide a means of separating c, and u,- but the Hall voltages associated with ionic conduction are at the nanovolt level and are generally too small to measure with any confidence. Furthermore, the validity of Hall measurements on hopping conductors is in doubt. 

Figure 18 Free carrier (electron) concentration in SiC samples implanted with P ions at RT (circles) and 1200 ° C (squares) as a function of annealing temperature. Annealing was performed for 20 min in Ar atmosphere. The electron concentration was obtained from Hall effect measurement at RT.

In crystalline semiconductors, the most common technique for the measurement of carrier mobility involves the Hall effect. However, in noncrystalline materials, experimental data are both fragmentary and anomalous (see, for example. Ref. [5]). Measured HaU mobility is typically of the order of 10 - 10 cm A /s and is frequently found to exhibit an anomalous sign reversal with respect to other properties providing information concerning the dominant charge carrier. Thus, apart from some theoretical interest, the Hall effect measurements are of minimal value in the study of macroscopic transport in amorphous semiconductors. 

To summarize the various results which suggest the energy level diagram of Fig. 1, many authors have shown (24,26,28) that zinc oxide has interstitial zinc as a donor impurity. As determined by conductivity and Hall effect measurements, the energy level for single ionization of this interstitial zinc is of the order of several hundredths of an electron volt below the conduction band when the concentration of donors is of the order of 10 cm. . The energy level for double ionization, from optical absorption measurements, appears to be at about 3.2 e.v. below the con-... 

Let us turn now to the other conclusions which can be based on free electron theory. The Hall effect measurements of Kyser and Thompson permitted the computation of the free electron concentration. The Hall effect is produced by a balance between the magnetic force (Lorentz force) on a current carrier and the electric force produced by a displaced charge density within a conductor. For a charge, q, moving... 

The number of characterization techniques that are sufficiently sensitive for this material and preferably impurity species or defect structure specific is rather small. Variable temperature Hall effect measurements in the Van der Pauw (1958) configuration allow the determination of (NA - ND). The... 

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