Preparation and Characterization of Surface‐Modified Luminescent Porous Silicon

Abstract

Porous silicon layers are chemically grafted with trimethylsiloxy groups by exposure to hexamethyldisilazane (HMDSj vapors. After treatment, infrared spectroscopy reveals that part of the initially hydrogenated surface is actually modified. Luminescence of the porous layers appears to be little affected by the treatment. On strongly luminescent samples, the photocarriers exhibit the same infrared absorption as in hydrogenated or oxidized porous silicon, evidencing the similar involvement of localized states in the luminescence process. The treated porous silicon layers also exhibit an increased stability against aging in ambient, as compared to hydrogenated porous silicon. Furthermore, the modification can be removed by simple exposure to H F vapor, thereby restoring the initial hydrogenated surface.

Mesoporous Silicon in Drug Delivery Applications

“…This enables a postanodization modification of the pore size distribution, which could also be utilized in drug delivery purposes 74, 75. While some results of the chemical derivatizations of the PSi surface with organic compounds and formation of SiC bonds were already reported previously,76–80 the reports by the group of Buriak finally confirmed the advantages of SiC bond in the stabilization 81, 82. After the Lewis acid catalyzed hydrosilylation, the PSi surface was stable even in boiling aqueous KOH 81…”

New biodegradable materials produced by ring opening polymerisation of poly(l-lactide) on porous silicon substrates

“…5 shows that the pSi-Ox-PLLA degrades at a rate of approximately 0.4% EOT per hour. The lack of a protecting silane layer exposes the pSi surface to hydrolytic attack [13,44,55,56], even in the presence of the PLLA nanobrushes. The low water contact angle of the pSi-Ox-PLLA (56 • ) compared with 62 • and 72 • for the pSi-HEAPS-PLLA and pSi-PEGS-PLLA samples also suggest that the pSi-Ox-PLLA surface is the most wettable and that the pSi layer will subsequently be more prone to hydrolytic degradation.…”

High surface area silicon materials: fundamentals and new technology

“…(a) Oxidation, shown first in this figure, is the simplest and most straightforward chemical functionalization but leads to a somewhat ill-defined, and electronically defective oxide interface. (b) The Si-C bond on porous silicon can be synthesized via a number of approaches using different organic molecular precursors, including alkenes, alkynes, alkyl halides, aryl diazonium reagents and carbanions (see Anderson et al 1993;Buriak et al 1999;Dubin et al 1995;Gurtner et al 1999;Henry de Villeneuve et al 1997;Kim and Laibinis 1998;Robins et al 1999;Song and Sailor 1999;Wacaser et al 2003).…”