Phonon-mediated desorption of image-bound electrons from dielectric surfaces

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.81.155420· OSTI ID:21366729

Heinisch, R L; Bronold, F X; Fehske, H ^[1]

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1. Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, 17489 Greifswald (Germany)

A complete kinetic modeling of an ionized gas in contact with a surface requires the knowledge of the electron desorption time and the electron sticking coefficient. We calculate the desorption time for phonon-mediated desorption of an image-bound electron as it occurs, for instance, on dielectric surfaces where desorption channels involving internal electronic degrees of freedom are closed. Because of the large depth of the polarization-induced surface potential with respect to the Debye energy, multiphonon processes are important. To obtain the desorption time, we use a quantum-kinetic rate equation for the occupancies of the bound-electron surface states, taking two-phonon processes into account in cases where one-phonon processes yield a vanishing transition probability as it is sufficient, for instance, for graphite. For an electron desorbing from a graphite surface at 360 K, we find a desorption time of 2x10{sup -5} s. We also demonstrate that depending on the potential depth and bound-state level spacing, the desorption scenario changes. In particular, we show that desorption via cascades over bound states dominates unless direct one-phonon transitions from the lowest bound state to the continuum are possible.

• OSTI ID: 21366729
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 81, Issue 15; Other Information: DOI: 10.1103/PhysRevB.81.155420; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOUND STATE
COMPUTERIZED SIMULATION
DEGREES OF FREEDOM
DESORPTION
DIELECTRIC MATERIALS
ELECTRONS
GRAPHITE
PHONONS
POLARIZATION
REACTION KINETICS
SURFACE POTENTIAL
SURFACES
TEMPERATURE RANGE 0273-0400 K
CARBON
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
KINETICS
LEPTONS
MATERIALS
MINERALS
NONMETALS
POTENTIALS
QUASI PARTICLES
SIMULATION
SORPTION
TEMPERATURE RANGE