Surface Photovoltage on Si(111)-(7x7) Probed by Optically-Pumped Scanning Tunneling Microscopy

Abstract

Scanning Tunneling Microscopy is combined with optical excitation techniques to probe spatially-resolved, non-equilibrium electronic transport processes at the Si(111)-(7x7) surface. Photo-excited carriers separate in the sub-surface space-charge region, producing a surface photovoltage which is detected using the STM tip as a potentiometer. While the photovoltage is uniform on well-ordered regions of Si(111)-(7x7), strong decreases are observed near virtually all defects. Differences in the functional dependence of the photovoltage on the illumination intensity are also observed. The spatial dependence of the photovoltage primarily results from spatial variations in the local surface recombination rate.

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Document Details

Document Type
Technical Report
Publication Date
May 15, 1990
Accession Number
ADA222004

Entities

People

  • K. Markert
  • R. J. Hamers

Organizations

  • IBM Thomas J. Watson Research Center

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Charge Carriers
  • Conduction Bands
  • Electric Fields
  • Electro-Optic Modulators
  • Electromagnetic Fields
  • Electron Holes
  • Electrons
  • Energy Bands
  • Fermi Levels
  • Measurement
  • Scattering
  • Semiconductor Devices
  • Semiconductors
  • Space Charge
  • Statistical Analysis
  • Three Dimensional
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Semiconductor Device Technology
  • Thin Film Deposition Science.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene
  • Space