Abstract
We report on the functionalization of Si NWs with C1-C6 alkyl chains using a versatile two step chlorination/alkylation process. We show that Si NWs terminated with C1-C6 molecules, through Si-C bonds, connect alkyl molecules to 50-100% of the Si atop sites and provide surface stability that depends on the chain length and molecular coverage, according to the following order: C1-Si NW > C2-Si NW > (C 3-C6)-Si NW. Our results indicate that the oxidation resistance of (C1-C2)-Si NWs is significantly higher than equivalent 2D Si(100) surfaces, whereas (C3-C6)-Si NWs are comparable to 2D (C3-C6)-Si(100). These discrepancies can be explained as follows: the lower the molecular coverage, the higher the probability for interaction between oxidizing agents (O2 or H 2O) and molecule-free sites. Our results are of practical importance when reduced amounts of oxide are required, e.g., for radial epitaxy on NWs to realize vertical P-N junctions for solar cells or for radial Si/Ge superlattices for application in optoelectronics.
Original language | English |
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Pages (from-to) | 19168-19172 |
Number of pages | 5 |
Journal | Journal of Physical Chemistry C |
Volume | 112 |
Issue number | 49 |
DOIs | |
State | Published - 11 Dec 2008 |
Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Energy
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films