SPI Surface Penning Ionization

SPI Surface Penning Ionization Neutral atoms, usually He, in excited states are incident on a surface at thermal energies. A surface electron may tunnel into the unoccupied electronic level, causing the incident atom to become ionized and eject an electron, which is then detected. This technique measures the density of states near the Fermi-level, and is highly surface sensitive. [Pg.21]

SPiES Surface Penning ionization Eiectron Spectroscopy... [Pg.1088]

SPIES Surface Penning ionization electron spectroscopy... [Pg.25]

Ultra-violet photoemission spectroscopy (UPS) probes the density of states, and ion neutralization spectroscopy (INS) and surface Penning ionization (SPI) provide similar information with probes of ions and metastable atoms, respectively. Angle-resolved UPS can determine the valence band structure. X-ray Photoelectron Spectroscopy (XPS) provides information on chemical shifts of the atomic core levels, and this can also help in understanding chemical bonding at the surface. [Pg.36]