Synthesis and photoluminescence of Cd-doped α-MnS nanowires

Cd-doped alpha-MnS nanowires (av diam = 70 nm) were synthesized by the chemical vapor deposition of MnCl2/CdS powders. They all consisted of single-crystalline rock-salt MnS structures with the [111] growth direction. The X-ray diffraction pattern analysis indicates that 10% Cd doping would expand the lattice constants by 0.3%. As the content of Cd increases, the band edge emission band (2.9 eV) of photoluminescence becomes broader, and the Mn2+ emission band (1.6 eV), which emerged at temperatures below similar to 150 K, decreases in intensity. The decay time of the 1.6 eV band decreases from 40 to 30 mu s when the Cd doping is increased from 0 to 10%. In contrast to the bulk (T-N = 150 K), the MnS nanowires were found to be paramagnetic with antiferromagnetic interactions. These distinctive magnetic properties of the nanowires have a strong correlation with their photoluminescence, which could be influenced by the nanosize effect and the Cd doping.