Skip to main content
Article
The Impact of Erbium Incorporation on the Structure and Photophysics of Silicon-Germanium Nanowires
Nanoscale (2010)
  • Ji Wu, Georgia Southern University
  • Monika Wieligor, Texas Christian University
  • T. W. Zerda, Texas Christian University
  • Jeffrey L. Coffer, Texas Christian University
Abstract

In this paper, we report multi-step processes for the fabrication of Er3+-doped SiGe nanowires(NWs) and characterization of their emissive properties. Three different alloyed architectures are obtained by altering the deposition sequences of Si and Er3+ on a Ge core NW, each involving a fixed concentration of these three elements. The deposition of Si onto the Ge NWcore, followed by an Er3+-rich layer on the outermost surface, permits facile formation of a SiGealloy given the lack of an erbium diffusion barrier; yet clustering of the erbium centers on the NW surface produces the weakest emitter. For nanowires prepared by co-depositing Si and Er3+ on top of the Ge core, the presence of impurity Er3+ ions greatly reduces the alloying rate of Si andGe such that less Si can diffuse into the Ge core. For this structure, the reduction of Er–Er interactions by a polycrystalline Si shell results in the strongest emission at 1540 nm. If an Er3+layer is inserted between the Ge and Si layers (a sandwich structure), it is found that Er3+ ions diffuse preferentially into the SiGe core instead of the silicon-rich shell, with a correspondingly weaker luminescence intensity. A combination of high resolution transmission electron microscopy, energy dispersive X-ray mapping, micro-Raman spectroscopy, andphotoluminescence spectroscopy are employed to derive these conclusions.

Keywords
  • Erbium,
  • Silicon-germanium nanowires,
  • Micro-Raman spectroscopy
Disciplines
Publication Date
2010
Citation Information
Ji Wu, Monika Wieligor, T. W. Zerda, and Jeffrey L. Coffer. "The Impact of Erbium Incorporation on the Structure and Photophysics of Silicon-Germanium Nanowires" Nanoscale 2 (2010): 2657-2667. doi:10.1039/C0NR00476F