Silicon nanoparticles with chemically tailored surfaces

Silicon nanoparticles are useful materials for optoelectronic devices, solar cells and biological markers. The synthesis of air‐stable nanoparticles with tunable optoelectronic properties is highly desirable. The mechanochemical synthesis of silicon nanoparticles via high‐energy ball milling produces a variety of covalently bonded surfaces depending on the nature of the organic liquid used in the milling process. The use of the C8 reactants including octanoic acid, 1‐octanol, 1‐octaldehyde and 1‐octene results in passivated surfaces characterized by strong SiC bonds or strong SiO bonds. The surfaces of the nanoparticles were characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The nanoparticles were soluble in common organic solvents and remarkably stable against agglomeration and air oxidation. The luminescence and optical properties of the nanoparticles were very sensitive to the nature of their passivating surface.