Electronic properties of methyl and hydrogen terminated Si(111) surfaces

ORAL

Abstract

Functionalized Si(111) surfaces have many applications in photo-electrochemistry, and some of those (e.g. the use of Si rods as photo-cathodes in solar cell applications) require the development of chemical protection strategies so as to prevent uncontrolled oxidation. Recently [1] a full methylation of Si(111) has been achieved experimentally, which constiutes a promising means to protect Si(111) from oxidation. However, the apparently simple atomic structure of this surface is still under debate. In particular, low temperature STM images appear to yield a pattern in disagreement with structural, first principles optimizations. We have carried out a series of ab-initio calculations of both the structural and electronic properties of the CH3-Si(111) aimed at interpreting STM and STS measurements. A comparison between results obtained at the DFT-GGA level and by using GW calculations will be presented and compared with the corresponding ones for the H-Si(111). This work supported by grant NSF-CHE-0802907 [1]H. Yu et al., Appl. Phys. Lett. 88, 152111, (2006)

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Authors

  • Antonio Aliano

    • Physycs Dep., Politecnico di Torino, 10129, Italy, Dept. of Chemistry UC Davis
    • Materials Science and Chemical Eng. Dep., Politecnico of Torino, Italy

  • Yan Li

    • Dept. of Chemistry UC Davis
    • Department of Chemistry, University of California, Davis, USA

  • Giancarlo Cicero

    • Dept. of Mat. Science and Chem. Eng., Politecnico di Torino, Italy
    • Materials Science and Chemical Eng. Dep., Politecnico of Torino, Italy

  • Giulia Galli

    • Dept. of Chemistry and Dept. of Physics, UC Davis
    • Department of Chemistry and Department of Physics, University of California Davis
    • Dept of Chemistry \& Dept Physics, UC Davis
    • Department of Chemistry and Department of Physics, UC Davis, USA
    • Department of Chemistry and Department of Physics, University of California, Davis
    • UC Davis
    • Department of Chemistry, University of California, Davis, USA
    • University of California, Davis
    • Department of Chemistry and Department of Physics, University of California, Davis, CA, 95616
    • Department of Chemistry and Department of Physics, University of California, Davis, CA 95616
    • Chemistry Department and Physics Department UC Davis, Davis CA