Size-Dependent Reactivity in Hydrosilylation of Silicon Nanocrystals

In situ gas-phase hydrosilylation of plasma-synthesized silicon nanocrystals.

Surface passivation of semiconductor nanocrystals (NCs) is critical in enabling their utilization in novel optoelectronic devices, solar cells, and biological and chemical sensors. Compared to the extensively used liquid-phase NC synthesis and passivation techniques, gas-phase routes provide the unique opportunity for in situ passivation of semiconductor NCs. Herein, we present a method for in ...

Size-dependent oxygen-related electronic states in silicon nanocrystals

Silicon nanocrystals embedded in SiO2 were isolated with a selective etching procedure, and the isolated nanocrystals’ excitonic emission energy was studied during controlled oxidation. Nanocrystals having initial diameters, d0, of ,2.9–3.4 nm showed a photoluminescence sPLd blueshift upon oxidatively induced size reduction, as expected from models of quantum confinement. Oxidation of smaller S...

Size classification of silicon nanocrystals

We report on the synthesis of size-classified silicon nanocrystals by differential mobility classification of a polydisperse ultrafine silicon aerosol. Using the described technique, the average nanocrystal size can be tuned by simply adjusting an electric field. Samples of nonagglomerated silicon nanocrystals have been obtained and size control has been achieved within 15%–20% in the 2–10 nm s...

Photoluminescent silicon nanocrystals with chlorosilane surfaces--synthesis and reactivity.

We present a new efficient two-step method to covalently functionalize hydride terminated silicon nanocrystals with nucleophiles. First a reactive chlorosilane layer was formed via diazonium salt initiated hydrosilylation of chlorodimethyl(vinyl)silane which was then reacted with alcohols, silanols and organolithium reagents. With organolithium compounds a side reaction is observed in which a d...

Size dependent carrier recombination in ZnO nanocrystals