TY - JOUR

T1 - Angular distribution of photoelectrons emitted from noncrystalline solids

AU - Chen, Yung-Fu

PY - 1997

Y1 - 1997

N2 - Monte Carlo simulations have been performed for studies of the influence of surface excitations on the angular distributions of photoelectron peak intensities. An extended Drude dielectric function, which allows the characteristic oscillator strength, damping constant, and critical-point energy for each subband of valence electrons, is employed to evaluate the position-dependent inelastic mean free paths of photoelectrons emitted from a solid surface. Elastic-scattering cross sections are calculated using phase-shift analysis and the finite difference method for a solid atom with the Hartree-Fock-Wigner-Seitz potential in the Dirac equation. Results of Monte Carlo simulations on the angular distribution of the four electron lines from gold, (Formula presented), (Formula presented), (Formula presented), and 4s are presented. Our calculations reveal that surface effects leads to a reduction of the intensities at small detection angles and a sharp decrease at large angles since the surface excitation is most probable for glancing electrons. However, the difference between the results obtained with and without surface effects may nearly disappear for the ratio of two different photoelectron intensities at small escape angles. Nevertheless, the calculated results taking into account surface effects are in better agreement with the experimental data.

AB - Monte Carlo simulations have been performed for studies of the influence of surface excitations on the angular distributions of photoelectron peak intensities. An extended Drude dielectric function, which allows the characteristic oscillator strength, damping constant, and critical-point energy for each subband of valence electrons, is employed to evaluate the position-dependent inelastic mean free paths of photoelectrons emitted from a solid surface. Elastic-scattering cross sections are calculated using phase-shift analysis and the finite difference method for a solid atom with the Hartree-Fock-Wigner-Seitz potential in the Dirac equation. Results of Monte Carlo simulations on the angular distribution of the four electron lines from gold, (Formula presented), (Formula presented), (Formula presented), and 4s are presented. Our calculations reveal that surface effects leads to a reduction of the intensities at small detection angles and a sharp decrease at large angles since the surface excitation is most probable for glancing electrons. However, the difference between the results obtained with and without surface effects may nearly disappear for the ratio of two different photoelectron intensities at small escape angles. Nevertheless, the calculated results taking into account surface effects are in better agreement with the experimental data.

UR - http://www.scopus.com/inward/record.url?scp=0041418975&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.55.5478

DO - 10.1103/PhysRevB.55.5478

M3 - Article

AN - SCOPUS:0041418975

SN - 1098-0121

VL - 55

SP - 5478

EP - 5484

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 8

ER -