Holes concentration

Phinyocheep, P. Tang, 1. M. Determination of the Hole Concentration (Copper Valency) in the High Superconductors, /. Chem. Educ. 1994, 71, A115-A118. 

It can be seen from Fig. 14.7 that the polarization curve for this reaction involving p-type germanium in 0.1 M HCl is the usual Tafel straight-line plot with a slope of about 0.12 V. For -type germanium, where the hole concentration is low, the curve looks the same at low current densities. However, at current densities of about 50 AJvcF we see a strong shift of potential in the positive direction, and a distinct limiting current is attained. Thus, here the first reaction step is inhibited by slow supply of holes to the reaction zone. 

Fig. 12. SIMS concentration profiles of B, H, and O in silicon. The inset shows the spreading resistance of this sample before (B) and after (A) hydrogenation. The hole concentration at the surface is 2.0 x 1019 cm-3 before and 1.4 x 1018 cm-3 after hydrogenation.

Fig. 4. Arrhenius plot of the free hole concentration in a beryllium-doped germanium crystal grown in a hydrogen atmosphere. The shallow acceptor A(Be,H), present at a concentration of 1013 cm-3, is shown to dissociate under thermal annealing. 

Fig. 9. Arrhenius plots of the free hole concentration p (log p versus 1000/T) in two samples cut from a partially dislocated slice of ultra-pure germanium. The dislocation-free sample contains an acceptor with Ev + 80 meV. The shallow level net-concentration is the same in both samples.

Electron and hole concentrations are often written as n and p, but this alternative will not be followed here to avoid confusion with pressure, also denoted as p.)... 

Figure 7.11 Computed polynomial plot for defect concentrations in a compound MX for the situation where Schottky defects are dominant, Ks = 104° defects m-3, Ke = 1032 defects m-3 [Eq. (7.36)] (a) hole concentration in MX as a function of partial pressure and (b) the complete diagram.

Exactly the same equations apply for cases in which the electronic defects dominate the equilibrium, so that Eq. (7.35) still represents the relationship between the hole concentration and partial pressure. The values of the equilibrium constants, however, are now changed. The revised values are ... 

Preparations under higher oxygen partial pressure would be expected to increase hole concentrations (CoCo ) and under lower partial pressures to increase the concentration of vacancies (Vo ). The exact defect population in a sample will depend upon temperature, oxygen partial pressure, and the rate at which samples are cooled. 

Holes, which initiate the dissolution process, are minority charge carriers in n-type electrodes. The concentration of holes nh is very low in n-type Si under equilibrium conditions. The hole concentration can be increased by illumination or by... 

The concentration of electrons, n, in the conduction band of n-type semiconductors and the hole concentration, p, in the valence band of p-type semiconductors are given by Eqn. 2-7 and Eqn. 2-10, respectively. The concentration of ionized donors, IVd-, and the concentration of ionized acceptors, iVx-, are derived by using the Fermi function approximated by the Boltzmann function as shown in Eqns. 2-18 and 2-19, respectively ... 

Similarly, one can derive an equation for a p-type semiconductor, where the distance between the Fermi energy level and the valence band is a logarithmic function of acceptor impurity concentration. As the acceptor impurity increases so too does the hole concentration in valence band, with the Fermi level moving closer to the valence band. 

Jv,Q is the exchange current density in the valence hand at equilibrium, ps denotes the equilibrium surface concentration of holes, ps represents the dynamic surface concentration of holes related to bulk surface hole concentration po by ... 

Figure 19 shows the free hole concentration as a function of reciprocal temperature for the samples implanted with B, co-implanted with C and B (C/B) and co-implanted with Si... 

Figure 19 Free hole concentration as a function of reciprocal temperature for B- (triangles), C/B-(circles), and C/Si-implanted (squares) SiC. Solid lines represent the fitting results.

The transport properties of the system Fe[V,Fe2-x]04 exhibit a sharp cusp at X == 1.89 and a large, positive Seebeck coefficient correlates well with a small hole concentration on the A sites in the domain 1.89 x < 2.0. The Mossbauer data also support the valency distribution... 

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