Carrier Injection and Scanning Tunneling Microscopy at the Si(111)-2x1 Surface

Research output: Contribution to journalArticlepeer-review


Surface photovoltage at the Si(lll)-2Xl surface is measured using a scanning tunneling microscope by simultaneously modulating the sample bias and the intensity of illumination from a He-Ne laser. In the limit of small tunneling current, the dependence of surface photovoltage on light intensity measured for p- and n-type Si gives the Fermi level at the surface, 0.46±0.03 eV. Tunneling out of the surface injects bulk carriers that reduce band bending at the surface of n-type Si. Tunneling into the surface reduces the surface photovoltage on p-type Si and increases the photovoltage on n type demonstrating that the tunneling current changes the surface potential by charging of surface electronic states or through bulk spreading resistance. Spatial variations in the surface photovoltage measured at positive sample bias and large tunneling current are observed at surface defects.

Original languageEnglish (US)
Pages (from-to)792-796
Number of pages5
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Issue number4
StatePublished - Jul 1993

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


Dive into the research topics of 'Carrier Injection and Scanning Tunneling Microscopy at the Si(111)-2x1 Surface'. Together they form a unique fingerprint.

Cite this