CdSe/CdTe core/shell nanowire heterostructures were synthesized not only in a noncoordinating octadecene (ODE) solvent but also in a coordinating tri-n-octylphosphine oxide (TOPO) solvent, using a relatively safe CdO as the Cd precursor instead of the highly toxic Cd(Me)(2) by a colloidal approach. The polycrystalline CdTe shell was formed in the Volmer-Weber island mode, and its morphology was controlled by delicately adjusting the reaction parameters. The as-prepared core/shell nanowires were characterized by various electron microscopic techniques, energy-dispersive X-ray spectroscopy (EDX) and corresponding elemental mapping, X-ray diffraction (XRD), UV-vis spectroscopy and transient absorption spectroscopy. (C) 2011 Elsevier B.V. All rights reserved.