Efficient Photoluminescence Upconversion in Porous Si

Abstract

We report on a new phenomenon specific for a system of spatially interconnected nanocrystal assemblies: efficient low temperature photoluminescence (PL) conversion at resonant optical excitation of porous Si. The upconverted photoluminescence (anti-Stokes PL) is observed at intensities as low as 0.1 W/cm(exp 2) and its intensity is as large as that of the Stokes PL band. The confirmation of the essence of connectivity between nanocrystals comes from the same type of studies performed on systems containing Si nanocrystals surrounded by a thick SiO(2) shell where the anti-Stokes PL is completely absent for any excitation energy and intensity used while the properties of the Stokes PL are very similar to those of porous Si.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2001
Accession Number
ADP013259

Entities

People

  • D. Kovalev
  • F. Koch
  • G. Polisski
  • J. Diener
  • N. Kuenzer

Organizations

  • Technical University of Munich

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption
  • Electrons
  • Energy
  • Excitation
  • Excitons
  • Hard Copy
  • High Energy
  • Intensity
  • Laser Beams
  • Military Research
  • Nanocrystals
  • Nanostructures
  • Optics
  • Photoluminescence
  • Physics
  • Technical Information Centers
  • Time Domain

Fields of Study

  • Materials science

Readers

  • Fluid Dynamics.
  • Materials Science and Engineering.
  • Optical Physics and Photonics.