Stable Scaffolds for Reacting Si Nanowires with Further Organic Functionalities while Preserving Si-C Passivation of Surface Sites

Functionalization of Si NWs with CH3sCHdCHs groups gives nearly full coverage of the Si atop sites. The resulting Si NWs provide high stability against oxidations and, at the same time, reactive functionality for further chemical modifications. In contrast, CH3sCtCs and CH3s functionalities, which give nearly full coverage of the Si atop sites too, could not achieve (simultaneously) the combination of stability and subsequent functionalization. The reported approach has the advantage of controlling the density of reactive cross-linkers without affecting the stability of the Si NWs. Formation of monolayers with a variety of termination groups is expected to open up a wide range of opportunities for producing stable molecule-based electronic devices. Immobilization of biomolecules or selective receptors on the Si NWs offers opportunities for the development of novel (bio)- chemical sensors. Attachment of redox active molecules or “molecular switches”10 to Si NWs could enable fabrication of molecular scale memory or logic elements integrated with conventional Sibased nanoelectronic devices.