Photoelectron energy distribution

Fig. 15. Angle-integrated photoelectron energy distribution curves of uranium in the region of the giant 5 d -> 5 f resonance (90 eV < hv < 108 eV). The 5 f intensity at Ep is suppressed by more than a factor of 30 at the 5 ds/2 threshold (see the spectra for hv = 92 and 94 eV) and resonantly enhanced above threshold (see, e.g., the spectrum for hv = 99 e V). At an initial energy 2.3eV below Ep a new satellite structure is observed which is resonantly enhanced at the 5 d5/2 and 5 ds onsets. At threshold the satellite coincides with the Auger electron spectrum, which moves to apparently larger initial energies with increasing photon energy (from Ref. 67)...

Fig. 2. Photoelectron energy distributions of trans-stilbene following the excitation with different photon energies, a) 316nm, b) 3 lOnm, c) 301nm and d) 266nm.

Figure 5 The photoelectron energy distribution is shown for electrons transmitted through layers of Cdar (dashed), Cdbr (dotted) and of mixed monolayers (solid) for three (A) and nine (b) layers.

For samples in good ohmic contact to the detector system the photoelectron energy distribution curve is referred to the Fermi level Ef. Adsorbate induced shifts of the photoemission spectra are thus related to changes of the binding energy values EB and changes of the work function Eg= hv - Efcin - 41 and Acft = - eVbb +... 

Fig. 8 Normalized temperature dependent photoelectron energy distribution spectra for photoelectrons emitted from gold coated with monolayers of (a) LC polyalanine, and (b) DN polyalanine. The laser wavelength was 266 nm (4.66 eV)...

This completes our brief description of the computational methods used in these studies. In the following sections some recent results will be presented and discussed. We will cover the calculation of ionization rates, the photoelectron energy distributions, the determination of the residual excited state populations remaining after excitation by a short pulse and finally show some photoemission spectra. The shape of the pulse envelope clearly can affect all these observable quantities. For example, the final state populations are found to be very sensitive to the pulse width and the peak intensity. Such results emphasize the point that in a strong, short pulsed field, the time dependence of the field envelope is reflected in the time evolution of the excitation dynamics. During the pulse. 

Fig. 9. Calculated photoelectron energy distribution for a laser wavelength of 1.053 pm and an intensity of 3 x 10 W/cm ...

P E, hv) is the distribution of photoelectron energy, E, excited by photon of energy, hv, T E) is the transmission function and D E) is the escape function. Both T E) and D(E) are smoothly varying functions. Therefore the structures in the observed intensities are almost entirely determined by P E, hv). The photoelectron energy distribution function is given by. 

We note that the work function increases upon CHC1, chemisorption for silver and copper clusters. The work-function change is monitored by the change in width of the photoelectron energy distribution curve (Table II). We find an increase in work... 

Fig. 12. Photoelectron energy distribution for Si lll 2 X 1. The filled surface state curve represents the difference between clean and oxidized surface curves and depicts the optical density of intrinsic surface states (after Eastman and Grobman [154]).

Given adequately prepared surfaces, angle-resolved photoemission and the various yield spectroscopies have been used to investigate filled and empty surface states, respectively. Results of angle-resolved photoemission measurements have been published by Knapp and Lapeyre [181], Williams et al. [182], Knapp et al. [183] and Huijser et al. [184], A typical set of angle-resolved photoelectron energy distributions (AREDCs) due to Huijser et al. [184] is shown in Fig. 16, in which four structures labelled B , SM S2 and B2 are observed. They are ascribed to emission from filled intrinsic states since they disappear on exposure to 10s L of H2. As we shall see below, B , S and S2 are primarily As-derived, while B2 is mainly a Gas-like state bonded to Asp-states. 

Figure 5.9 shows the photoelectron energy distribution of Fe/W(110) obtained in normal emission for oppositely magnetized (M", M ) films and the corresponding asymmetry A = — 7 —)/(/ + 7 ). The angle of photon... 

Fig. 13. Photoelectron energy distributions for YH2 for low photon energies. The bonding band is revealed by the emission form 3 to 10 eV below Et the narrow band at E is the metal derived conduction band (Weaver and Peterson, 1979).

The photoelectron kinetic energy (or wave number) dependent photoelectron angular distribution for ionization to state c, Pc,kj(( k,k,t, tpr), and the photoelectron energy distribution for ionization to state c, Pc ek,t]tpr), may be defined as parts of Eq. (3.87),... 

Fig. 5.5 shows the photoelectron energy distributions as a function of pump-probe delay time with the probe polarization parallel to the molecular axis. As is expected from previous model studies of this system [63,78], the kinetic... 

Figure 5.10 Determination of the work function from the total width of a photoelectron energy distribution. The left part shows a schematic energy diagram for the photoexcitation of electrons from the Fermi level into final states, which can propagate into the vacuum. The right side shows a typical photoelectron energy distribution.

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