Surface Photovoltage of Ag on Si(111)-7X7 by Scanning Tunneling Microscopy
Abstract
Using a scanning tunneling microscope and light from a He-Ne laser, we have measured the surface photovoltage of the Si(111)-7X7 surface with coverages of Ag up to 1 monolayer. The data agree with a model for the photovoltage based on the recombination of photoexcited minority carriers with majority carriers thermally excited over the surface Schottky barrier. The surface Fermi level positions derived from these data are consistent for n and p type Si decreasing from 0.60 eV above the conduction band maximum for the clean surface to 0.40 eV near 1 monolayer coverage. Although our photovoltage data are spatially resolved on an atomic scale, we do not observe any spatial variation in the photovoltage on the clean surface or on surfaces partially covered by Ag islands.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 30, 1991
- Accession Number
- ADA236971
Entities
People
- David G. Cahill
- R. J. Hamers