Reflection Electron Energy Loss Spectroscopy of Alkali Metals on Silicon

• Authors: Ch. Kleint , S. Abd El-Halim
• Languages of publication: EN

Abstracts

EN

In an extended introduction studies of alkali adsorption on clean silicon surfaces are shortly reviewed and recent achievements are outlined. The main part describes our investigations of lithium and potassium adsorption by reflection electron energy loss spectroscopy (REELS). Beside (electronic) valence electron excitations also core losses of both silicon and these alkali metals were observed in the ionization loss spectroscopy mode (ILS). Additional information has been obtained by Auger electron spectroscopy (AES) and measurements of work function changes (WFC). The spectra of Li and K adsorption on the Si(100) plane show considerable differences which will be discussed in detail. By simulation of the REEL potassium spectra within the density of states (DOS) model using the Si(100)2 × 1 K DOS by R. Ramirez the origin of the 8.4 and 12.5 eV loss peaks can be traced to band structure features. In addition the known K peaks at 18.1, 20 and 22 eV are confirmed and their behaviour with increasing primary energy E_{p}, was investigated. While the K 3p-K 4s transition corresponding to the 18.1 eV loss increases with E_{p}, the dipole-forbidden K 3p-K 4p transition (20 eV) decreases. Shifts in the loss energy of these peaks as well as in the core loss energies at 295 and 296.8 eV are observed and explained by charge transfer.

Keywords

EN

73.20.-r; 79.20.Fv; 79.20.Hx

Discipline

• 79.20.Fv: Electron impact: Auger emission(for Auger electron spectroscopy, see 82.80.Pv)
• 73.20.-r: Electron states at surfaces and interfaces
• 79.20.Hx: Electron impact: secondary emission

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1992
• Volume: 81
• Issue: 1
• Pages: 47-65

Dates

published

1992-01

received

1991-05-21

(unknown)

1991-08-01

Contributors

author

Ch. Kleint

• Sektion Physik, Universität Leipzig, Linné str. 5, (O)-7010 Leipzig, Germany

author

S. Abd El-Halim

• Sektion Physik, Universität Leipzig, Linné str. 5, (O)-7010 Leipzig, Germany

Identifiers

DOI

10.12693/APhysPolA.81.47