Diffusion of Mn in ZnO nanowires annealed in air.
We studied diffusion of Mn in ZnO nanowires by means of field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, photoluminescence and Raman scattering spectroscopy. The Mn-diffused samples were prepared by covering synthesized ZnO nanowires with a Mn chip and then annealing at temperatures between 200 and 1000 degrees C for 1 h in air. Microstructural analyses, and photoluminescence and Raman studies revealed that Mn atoms started diffusing in ZnO nanowires at 800 degrees C. The annealing-temperature increase up to 1000 degrees C led to a strong diffusion of Mn in the ZnO host lattice, which caused the blueshift of the ultra-violet emission. Concurrently, recored Raman scattering spectra showed some additional Mn-related modes. The origin of these lines was discussed in detail.
Micro- and Nano-Structures Group, H. H. Wills Physics Lab, University of Bristol, Bristol BS8-1TL, UK.
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Vincent
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