Soft X-ray Induced oxidation on acrylic acid grafted luminescent silicon quantum dots in ultrahigh vacuum

摘要

As the basic building block of semiconductor electronics, silicon is a widely available, comparatively cheap, ecologically friendly and technologically well developed material. Since 1990, when Canham [1] found silicon nanostructures were able to emit visible light, interest in nanoscale silicon structures has risen sharply throughout the wider scientific community [2-11 ]. Owing to their ability to emit red light and lack of toxicity [12, 13], silicon quantum dots (Si-QDs), are deemed to be one of the best candidates as bio-labels for applications in bio-imaging. However, their full potential faces a major barrier in respect of their water solubility. Unfortunately the popular alkyl-capped Si-QDs are hydrophobic, and cannot be dissolved in water. Thus they are of limited use in a wide range of biological applications. Several groups have attempted to make the QDs water soluble by various routes [14-18]. Warner etal. [19] produced allylamine-capped Si-QDs using a Pt catalyst.