Nonthermal plasma synthesized freestanding silicon-germanium alloy nanocrystals.
The composition, structure, light emission and oxidation kinetics of Si(1-x)Ge(x) alloy nanocrystals ( approximately 3 nm in diameter) synthesized by nonthermal plasma have been investigated. It is found that the synthesized nanocrystals are neither a mixture of Si nanocrystals and Ge nanocrystals nor Si-Ge (Ge-Si) core-shell nanocrystals. The H coverage at the surface of Si(1-x)Ge(x) nanocrystals decreases with the increase of the Ge atomic fraction. The incorporation of Ge enhances the oxidation of Si(1-x)Ge(x) nanocrystals when the atomic fraction of Ge is <0.5. No shift in photoluminescence from hydrosilylated Si(1-x)Ge(x) nanocrystals is observed when the atomic fraction of Ge varies between 0 and 0.1, indicating that the bandgap of Si nanocrystals is similar to that of Ge nanocrystals at a nanocrystal size of 3 nm.
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Department of Mechanical Engineering, University of Minnesota, Minneapolis 55455, USA. xdpi@zju.edu.cn
Kortshagen
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D000497:Alloys / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D005857:Germanium / Q000737:chemistry*; D006858:Hydrofluoric Acid / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology / Q000379:methods*; D044367:Phase Transition; D012825:Silicon / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction
D000497:Alloys; D005740:Gases; D005857:Germanium; D006858:Hydrofluoric Acid; D012825:Silicon