Size-independent organosilane functionalization of silicon nanocrystals using Wilkinson's catalyst

A low-temperature size-independent method for modifying the surface chemistry of the silicon nanocrystal (SiNC) surface is reported. Wilkinson's catalyst has been applied to accelerate the dehydrogenative coupling reaction between organosilane molecules and hydride-terminated SiNCs. Two strategies and multiple organosilanes were evaluated to study surface modification efficiency. During the investigations, it was determined that surface functionalization efficiency showed some dependence upon the organic modifier in question. The comparatively low reactivity of octadecyldimethyl silanes may result from the formation of Si-Rh-Si intermediates hindered by the steric bulk of the silanes when reacted with activated SiNCs. Quenching of the SiNC-based photoluminescence is observed and the origin of this phenomenon has been attributed to the present of trace rhodium on SiNCs detected using X-ray photoelectron spectroscopy.