(354a) Mechanochemical Synthesis Of Blue Luminescent Functionalized Silicon Nanoparticles

A mechanochemical method for the synthesis of alkyl passivated blue photoluminescent silicon nanoparticles using high energy ball milling (HEBM) is described. The method provides for the simultaneous production of photoluminescent silicon nanoparticles and the passivation of the particle surface with alkyl groups covalently linked through Si-C bonds. As fresh silicon surface is formed during HEBM by particle fracture, the surface Si atoms react in-situ with liquid alkyls, such as 1-octyne and 1-hexyne. Functionalized silicon nanoparticles with physical dimensions less than the bulk Bohr radius of silicon display intense photoluminescence due to quantum size effects, and have exhibited a quantum yield of 0.60. The fluorescent nanoparticles are then characterized using spectroscopic techniques such as photoluminescence, NMR, and FTIR. The effects of mechanochemical processing parameters such as milling time and reactive media on nanoparticles properties and surface functionalization are described.