Highly photoluminescent and stable silicon nanocrystals functionalized via microwave-assisted hydrosilylation

Herein, wereport amicrowave-assisted hydrosilylation (MWH) reactionfor the surfacepassivation of silicon
nanocrystals (Si-NCs) with linear alkenes. The MWH reaction requires only 20 minutes and allows us to
produce Si-NCs with high photoluminescence quantum yields (PLQYs), reaching 39% with an emission
maximum of 860 nm. Furthermore, we investigated the effect of ligand length on the
photoluminescence properties of Si-NCs. We tested six alkenes with an even number of carbon atoms
(from hexene-1 to hexadecene-1). The highest PLQY combined with a long stability (test period of 6
months) was observed when capping with the shortest ligand, hexene-1. The use of microwave heating
turns the hydrosilylation step into a facile and sustainable process. In order to provide insight into the
emissive properties of Si-NCs surface oxidation and luminescence decay were investigated using
Fourier-transform infrared spectroscopy and time-resolved photoluminescence measurements