Controlled synthesis of high quality PbSe and PbTe nanocrystals with one-pot method and their self-assemblies

High quality PbSe and PbTe nanocrystals were synthesized with non-injection one-pot method which could be scale up easily. The use of traditional dangerous pyrophoric trioctylphosphine (TOP) and tributylphosphine (TBP) reagents was avoided. The crystal size was controlled by the reaction time and temperature, and the shape (sphere and cube) was controlled by the use of different combinations of surfactants. X-ray diffraction (XRD) and selective area electron diffraction (SAED) characterizations demonstrated the rock salt cubic structures; the transition electron microscopy (TEM) images show narrow size distributions of as-synthesized PbSe and PbTe nanocrystals. The uniform size of as-synthesized nanocrystals promoted the self-assemble of PbSe and PbTe nanocrystals into ordered superstructures.