초록 |
In this research, we report the fine size tuning of PbSe nanocrytals with atomic-level precision and the morphologically controlled 2-dimensional PbSe nanosheets. The approach involves slow injection of precursors with excess amounts of oleic acid. Retarded growth, due to both the slow supply of precursors and the surfeit of oleic acid, causes attachment of PbSe nanocrystals through the (110) planes, the most reactive planes, into a two-dimensional geometry. In contrast, such attachment process can be prevented by impurities, e.g., Cd chalcogenide (CdSe or CdS) nanocystals dispersed in chloroform, resulting in the growth of monodisperse PbSe nanocrystals. |