The formation of Ga-, Mn- and Ca-GaAs(110) interfaces is studied with soft x-ray and ultra-violet photoemission spectroscopy. Band bending at the semiconductor surface is analyzed in terms of a two-step model of the pinning of the Fermi level. At low coverage, adsorbate induced donor states produce rapid band bending on p-GaAs. A well defined trend in the energy level of the adsorbate-induced donor state vs ionization energy of the adatom emerges from these and previous data on In-, A1-, Ag-, Au-, Pd-, and Sn-GaAs(110) interfaces. At high coverage, the pinning of the Fermi level is associated with appearance of metallic character at the interface.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry
- Schottky barrier
- low temperature