NOVELTY - Method (I) of making II-VI core-shell semiconductor nanowires (215) comprises: (a) providing a support (200); (b) depositing a layer including metal alloy nanoparticles (230) on the support; (c) heating the support and growing II-VI core semiconductor nanowires, where the metal alloy nanoparticles act as catalysts and selectively cause localized growth of the core nanowires; and (d) modifying the growth conditions and shelling the core nanowires to form II-VI core-shell semiconductor nanowires.    USE - The method is useful for making II-VI core-shell semiconductor nanowires (claimed), which are useful in optoelectronic, electronic and optical applications including light emitting diodes, lasers, rectifiers, solar cells, transistors or phosphors.    ADVANTAGE - The method: provides nanowires with high quality, high quantum efficiency and low defect; enhances transport of the electrons and holes in the core region of the nanowires; and provides low cost semiconductor optoelectronic and electronic devices with good performance utilizing the nanowires.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for method (II) of making II-VI core-shell semiconductor nanowires comprising: step (a) and (b) as above per se; (e) heating the support and flowing II-VI semiconductor precursors to selectively provide localized growth of II-VI core semiconductor nanowires, where the metal alloy nanoparticles act as catalysts; and (f) modifying the growth conditions and shelling the core nanowires to form II-VI core-shell semiconductor nanowires by flowing II-VI semiconductor precursors to impinge upon the core semiconductor nanowires and obtain non-selective growth.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of II-VI core-shell semiconductor nanowire including doped discrete heterostructure units.    Support (200)    Core-shell semiconductor nanowires (215)    Discrete heterostructure units (222)    Dopants (224)    Metal alloy nanoparticles (230)