Abstract
Some ligand effects on synthesis of PbSe nanocrystals presented here were different from the previously well-established model on the basis of the mostly-studied CdSe nanocrystals. We have demonstrated that the ligand effects played an important role in the growth mechanism of nanocrystals, addressing that tributylphosphine (the ligand of selenium monomers) could produce relatively smaller and more monodisperse PbSe nanocrystals than the generally used ligand, trioctylphosphine. In comparison, manipulating the ligand of lead monomers resulted in drastic effect on the nanocrystal growth. The post-synthetic investigation of surface ligand effects illustrated that the desorption of both ligands and their bonded atoms was observable. The additional introduction of surface ligands did not improve or stabilize PbSe nanocrystals, but instead caused the nanocrystals to shrink much faster. This study provided some insight into the stability of labile PbSe nanocrystals.