The reported deposition temperatures of II-VI semiconductor films of the highest optoelectronic quality are well below the typical growth temperatures of Au-catalyzed II-VI nanowires. Alternatively using Au-Sn as a nanowire catalyst enables the vapor-liquid-solid mechanism to operate at lower temperatures, where less defective material can be obtained. Zn-based II-VI nanowires were grown by metal organic vapor phase epitaxy at 320 degrees C. Microscopy and photoluminescence spectroscopy indicate that the highest quality nanowires were obtained at a Au:Sn volume ratio of 1:3, resulting in the formation of untapered, twin-free nanowires. Comparing the photoluminescence of ZnSe nanowires, with and without a shell of ZnMgSSe, shows that high quality core nanowires have some sub-bandgap defect emission which can be effectively removed by proper shelling. (C) 2011 Elsevier B.V. All rights reserved.