Phosphine-free synthesis of high quality zinc-blende CdSe nanocrystals in air

Based on a phosphine-free synthesis route, a safe, common, low-cost, non-coordinating solvent (liquid paraffin) was used as matrix for the synthesis of CdSe nanocrystals. High quality zinc-blende (cubic) CdSe nanocrystals have been synthesized by using stearic acid as a ligand under the air condition. Adding n-hexadecylamine into reaction solution, highly homogeneous and luminescent CdSe nanocrystals in the less common zinc-blende crystal structure have been obtained. The reproducibility of the synthesis of CdSe NCs by this route was discussed. Without any size sorting, the size distribution of the nanocrystals can be readily controlled and the higher photoluminescence quantum efficiency of the nanocrystals was up to 20-30%.