Morphology-controlled Lead Selenide Nanocrystals and Their In Situ Growth on Carbon Nanotubes

Abstract

High-quality colloidal lead selenide (PbSe) nanocrystals (NCs) were synthesized with various morphologies in a controlled manner by changing the growth temperature and capping ligand. When oleic acid was used as a ligand and activating agent for the Pb precursor, the evolution of the NCs from nanodots to nanocubes was achieved. The nanocubes can be progressively transformed into nanosized flowers, stars, hexapods, and tetrapods by decreasing the growth temperature, when using phosphonic acid instead of oleic acid. The tetrapods, whose branches are grown along the [111] direction, were produced at the lowest temperature. These systematic morphology-control strategies were applied to the in situ growth of PbSe NCs on carbon nanotubes, showing the successful production of dot, octahedron, tetragon, zigzagged rod, and tapered hexapod shaped PbSe NCs. We suggest that the carbon nanotubes would enhance the [100] growth of PbSe NCs, forming unique morphologies, which were not observed without carbon nanotubes.