Fast, High Yield, and High Solid Loading Synthesis of Metal Selenide Nanocrystals

Abstract

The synthesis of metal selenide nanocrystals based on the injection of selenium powder in a hot mixture containing the metal cation precursor complexed by a carboxylic acid is demonstrated by means of the formation of CdSe and ZnSe nanocrystals. In both cases, the synthesis can reach reaction yields of 80–85% within 5 min. In the case of CdSe nanocrystals, a more extensive study shows that even without protective atmosphere, the synthesis leads to state-of-the-art nanocrystals with low size dispersion. Importantly, the size of the nanocrystals at close to full yield can be changed by varying the carboxylic acid chain length, whereas the solid loading, that is, the amount of nanocrystals formed over the reaction volume, of the synthesis can be the 10-fold of typical literature syntheses. The potential of this reaction for the scaled up production of metal selenide nanocrystals is discussed and supported by the automated, parallel synthesis of CdSe nanocrystal batches using this heterogeneous selenium precursor where the standard deviation on the nanocrystal diameter is less than 1.5%.