Low temperature II–VI nanowire growth using Au–Sn catalysts

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 °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.