Synthesis of Colloidal PbSe/PbS Core−Shell Nanowires and PbS/Au Nanowire−Nanocrystal\nHeterostructures

Abstract

The oriented attachment of PbSe nanocrystals results in single-crystalline colloidal PbSe nanowires. The\naddition of different surfactants allows tailoring nanowire morphology, choosing between straight, zigzag,\nhelical, and branched nanowires. In this work, we studied the formation of coaxial PbSe/PbS core−shell\nheterostructures and observed Stranski−Krastanov growth regime of PbS shell on PbSe nanowires at low\nreaction temperature (150 °C) that switched to layer-by-layer epitaxial growth above 180 °C. The protection\nof PbSe nanowires with a PbS shell substantially improves the nanowire stability against oxidation. We also\ndeveloped a technique for controllable decoration of colloidal PbSe nanowires with Au nanoparticles and\nfound that the morphology of nanowire template had a strong effect on nucleation and growth of gold\nnanoparticles.