Narrow band UV emission from direct bandgap Si nanoclusters embedded in bulk Si

J Phys Condens Matter. 2010 Feb 24;22(7):072203. doi: 10.1088/0953-8984/22/7/072203. Epub 2010 Feb 2.

Abstract

We report on the formation of UV emitting Si nanoclusters (NCs) in Si, using a two stage Au implantation technique. These Si NCs, with an average size of 2 nm, show photoluminescence at room temperature, over a narrow band of about 100 meV with a peak of emission near 3.3 eV. With emission lifetimes in the range of 1.5-2.5 ns, the transitions seem to come from excitonic recombinations across a quasi-direct gap. Since the structures are below the surface, there is no adverse effect of oxidation resulting in a shift in emission wavelength. On the other hand, an annealing at 500 °C has been found to result in a significant increase in the emission intensity. This is due to localized plasmon induced electric field enhancement in Au nano-islands in the vicinity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Gold / chemistry*
  • Nanostructures / chemistry*
  • Nanotechnology*
  • Particle Size
  • Silicon / chemistry*
  • Surface Properties
  • Ultraviolet Rays*

Substances

  • Gold
  • Silicon