Role of the Si excess on the excitation of Er doped SiOx

The authors have investigated the role of the Si excess on the photoluminescence properties of Er doped substoichiometric SiO_x layers. They demonstrate that the Si excess has two competing roles: when agglomerated to form Si nanoclusters
Si-nc’s it enhances the Er excitation efficiency but it also introduces new nonradiative decay channels. When Er is excited through an energy transfer from Si-nc’s, the beneficial effect on the enhanced excitation efficiency prevails and the Er emission increases with increasing Si content. However, when pumped resonantly, the Er luminescence intensity always decreases with increasing Si content. These data are presented and their implications are discussed.

For more info:

• Role of the Si excess on the excitation of Er doped SiO_x
  G. Franzò, E. Pecora, F. Priolo, F. Iacona
  Applied Physics Letters 90, 183102 (2007)
• Er-based materials for Si microphotonics
  F. Iacona, G. Franzò, M. Miritello, R. Lo Savio, E. Pecora, A. Irrera, F. Priolo
  Optical Materials, 31, 1269 (2009)
• Erbium doped materials for a Si-based microphotonics
  F. Priolo, G. Franzò, F. Iacona, A. Irrera, R. Lo Savio, M. Miritello, E. Pecora
  Solid State Phenomena 131-133, 563 (2008)