Hydrogen-induced metallization on Ge(1 1 1) c(2 × 8)
2006 (English)In: Applied Surface Science, ISSN 0169-4332, Vol. 252, no 15, 5300-5303 p.Article in journal (Refereed) Published
We have studied hydrogen adsorption on the Ge(1 1 1) c(2 × 8) surface using scanning tunneling microscopy (STM) and angle-resolved photoelectron spectroscopy (ARPES). We find that atomic hydrogen preferentially adsorbs on rest atom sites. The neighbouring adatoms appear higher in STM images, which clearly indicates a charge transfer from the rest atom states to the adatom states. The surface states near the Fermi-level have been followed by ARPES as function of H exposure. Initially, there is strong emission from the rest atom states but no emission at the Fermi-level which confirms the semiconducting character of the c(2 × 8) surface. With increasing H exposure a structure develops in the close vicinity of the Fermi-level. The energy position clearly indicates a metallic character of the H-adsorbed surface. Since the only change in the STM images is the increased brightness of the adatoms neighbouring a H-terminated rest atom, we identify the emission at the Fermi-level with these adatom states.
Place, publisher, year, edition, pages
Elsevier , 2006. Vol. 252, no 15, 5300-5303 p.
Scanning tunneling microscopy; Angle-resolved photoelectron spectroscopy; Hydrogen adsorption; Ge(1 1 1) c(2 × 8)
IdentifiersURN: urn:nbn:se:liu:diva-17368DOI: 10.1016/j.apsusc.2005.12.062OAI: oai:DiVA.org:liu-17368DiVA: diva2:208842