Fowler-Nordheim

Fig. 8. Band-to-band tunneling in a semiconductor where the triangular barrier leads to Fowler-Nordheim tunneling (33).

Fig. 13. Electric-field dependence of the emission current obtained for a carefully aligned MWCNT film [38], Inset Fowler-Nordheim plot, where y is the field-enhancement factor.

Fluctuating Gap Model Fowler-Nordheim fluorine-doped tin dioxide full width at half maximum geminate pair... 

The field-induced tunneling across a potential barrier can be described using the Fowler-Nordheim equation [79] ... 

However, the values for the current, which are obtained using the Fowler-Nordheim equation with the actual device parameters, are several orders of magnitude [81, 82) higher than the values for the measured current in real devices. 

For the same the single layer devices based on Alq3, Peyghambarian et al. [83] found that the 1/V characteristics can also be described by an SCL current flow in the low cu ire lit regime. However, in the low current regime the 1/V characteristics can be qualitatively modeled by the Fowler-Nordheim equation (even if, quantitatively, the real device current differs from the calculated by seven orders of magnitude) [83] and thermionic emission ]78]. 

Fowler-Nordheim tunneling of, 22 258 in HBTs, 22 167-168 Moore s law and device scaling and, 22 254 in RTDs, 22 170-171 in semiconducting silicon, 22 485-486 in semiconductors, 22 233, 237-239 in SETs, 22 171-172 in single layer OLEDs, 22 215-216 in spinel ferrites, 11 60-61 in the superconducting state, 23 804 Electron spectrometer system, components of, 24 100-101... 

Fig. 10.19 (a) Current-voltage characteristic of the cold cathode according to the circuit shown in Fig. 10.18. (b) A Fowler-Nordheim... 

Field emission is the emission of electrons from a solid under an intense electric field, usually at ambient temperatures. It occurs by the quantum mechanical tunneling of electrons through a potential barrier (Fig. 13.1). This leads to an exponential dependence of emission current density J on the local electric field, as given by the Fowler Nordheim equation,... 

CO adsorbed Pd/Al Oj, 37 69-70 diffuse reflectance spectroscopy, 34 14 Fowler-Nordheim equation, 21 72 Fraction exposed, of total metal atoms definition, 36 72-73... 

Fig. 24 Schematic representation of electron injection from a metallic electrode into a semiconductor (a) via Schottky emission, (b) via Fowler-Nordheim tunneling, and (c) via hopping in a disordered organic solid.

Fig. 1.38. The Fowler Nordheim equation for field emission. The relevant dimensions are much smaller than the tip radius. Therefore, a one-dimensional model is adequate. Neglecting the image-force effect, the potential U(z) outside the metal surface is linear with respect to distance z- The relevant parameters are work function of the material, tj), and the field intensity near the surface, F.

Eq. (1.34) is the simplified version of the Fowler-Nordheim equation. In the original Fowler-Nordheim equation, there is an algebraic prefactor to the exponential factor. Experimentally, the exponential factor always dominates the functional dependence, leaving the existence and the specific form of the algebraic factor hardly distinguishable (see Fowler and Nordheim, 1928 Good and Muller, 1956). In practical units (work function cj> in eV, and the field intensity F in V/A), Eq. (1.34) becomes... 

The standard method for treating field-emission data is to make a plot of the logarithm of field-emission current In / versus MV or 1/F, then fit the data points with a straight line. This plot is called a Fowler-Nordheim plot (Good and Muller, 1956). 

According to the Fowler-Nordheim equation, Eq. (1.34), the field-emission current from electrons at energy j E below the vacuum level is proportional to... 

Agarwal, A. K., S. Seshadri, and L. B. Rolland, Temperature Dependence of Fowler-Nordheim Current in 6H- and 4H-SiC MOS Capacitors, IEEE Electron Device Letters, Vol. 18, Issue 12, December 1997, pp. 592-594. 

Hui-Feng, L., et al., Analysis of Fowler-Nordheim Injection in NO Nitrided Gate Oxide Grown on n-Type 4H-SiC, Microelectronics Reliability, Vol. 40, No. 2, February 2000, pp. 283-286. 

The dipole moment of adsorbed atoms can be derived by measuring the change in work function as a result of the presence of the adatoms. In macroscopic measurements, the states of the deposited adatoms are unknown. They may combine into clusters of different sizes and some of them may be absorbed into lattice steps. One can also use the field emission microscope for this purpose. However, similar uncertainties exist. To achieve a well characterized surface and a known number of individual adsorbed atoms on a surface, a combined experiment with field ion microscope observations and field emission Fowler-Nordheim (F-N) plots has been most successful.198,200... 

Differences in work function occur not only on different faces of a clean metal crystal, but result also from the presence of adsorbed films, or monolayers of gases. Since the work function appears to the (l -power in the exponent of the Fowler-Nordheim equation (Equation 4), changes in X of a few hundredths of an electron volt produce marked changes in emission. 

It should be pointed out here that large decreases in the pre-exponential term of the Fowler-Nordheim equation occur on oxygen adsorption, so that the slope of a log Z/F vs. 1/V plot should be used for determination of X- These decreases were also found by Muller (1) for oxygen and by the writer for hydrogen on tungsten. They may correspond, at least in part, to a decrease in effective emitting area, both micro- and macroscopically. 

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