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Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems
Published on: April 28, 2016
Si nanorod length dependent surface Raman scattering linewidth broadening and peak shift
Gong-Ru Lin1, Yung-Hsiang Lin, Yi-Hao Pai
1Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan. grlin@ntu.edu.tw
Optics Express
|January 26, 2011
Summary
This study shows that longer silicon nanorods enhance Raman scattering intensity due to increased surface area and dangling bonds. Oxidation passivates these bonds, reducing the scattering signal.
Area of Science:
- Materials Science
- Nanotechnology
- Spectroscopy
Background:
- Silicon nanostructures are crucial for advanced electronic and photonic devices.
- Raman scattering is a key technique for characterizing semiconductor materials.
- Surface properties significantly influence the optical and electronic behavior of nanomaterials.
Purpose of the Study:
- To investigate the effect of silicon nanorod length on enhanced Raman scattering.
- To understand the role of surface dangling bonds and oxidation in modulating Raman signals.
- To correlate nanorod morphology with optical properties.
Main Methods:
- Metal-particle-catalyzed etching to fabricate vertically aligned silicon nanorods.
- Systematic variation of nanorod length (0.19 to 2.73 μm).
- Raman spectroscopy to measure scattering intensity, peak shift, and linewidth.
- Fourier transform infrared (FTIR) spectroscopy to analyze surface chemistry.
Main Results:
- Enhanced Stoke Raman scattering intensity correlates linearly with increased surface area and silicon dangling bonds.
- Raman peak shifts and linewidth broadening increase with nanorod length, indicating surface strain and crystal quality effects.
- Oxidation leads to the formation of Si-O-Si bonds, passivating dangling bonds and attenuating Raman scattering.
Conclusions:
- Silicon nanorod length is a critical parameter for controlling Raman scattering intensity.
- Surface dangling bonds significantly enhance Raman signals, while oxidation passivates them.
- Understanding these surface effects is vital for optimizing silicon nanostructures in optoelectronic applications.
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