Silicon nanocrystals with ensemble quantum yields exceeding 60%

Silicon nanocrystals with diameters of less than 5 nm show efficient photoluminescence at room temperature. For ensembles of silicon quantum dots, previous reports of photoluminescence quantum yields have usually been in the few percent range, and generally less than 30%. Here we report the plasma synthesis of silicon quantum dots and their subsequent wet-chemical surface passivation with organic ligands under. strict exclusion of oxygen. Photoluminescence quantum yields exceeding 60% have been achieved at peak wavelengths of about 789 nm. (c) 2006 American Institute of Physics.