An investigation into the conversion of In2O3 into InN nanowires
1 Department of Physics, Research Centre of Ultrafast Science, University of Cyprus, P.O. Box 20537, Nicosia, 1678, Cyprus
2 Nanostructured Materials and Devices Laboratory, Department of Mechanical Engineering, Materials Science Group, School of Engineering, University of Cyprus, P.O. Box 20537, Nicosia, 1678, Cyprus
Nanoscale Research Letters 2011, 6:311 doi:10.1186/1556-276X-6-311Published: 7 April 2011
Straight In2O3 nanowires (NWs) with diameters of 50 nm and lengths ≥2 μm have been grown on Si(001) via the wet oxidation of In at 850°C using Au as a catalyst. These exhibited clear peaks in the X-ray diffraction corresponding to the body centred cubic crystal structure of In2O3 while the photoluminescence (PL) spectrum at 300 K consisted of two broad peaks, centred around 400 and 550 nm. The post-growth nitridation of In2O3 NWs was systematically investigated by varying the nitridation temperature between 500 and 900°C, flow of NH3 and nitridation times between 1 and 6 h. The NWs are eliminated above 600°C while long nitridation times at 500 and 600°C did not result into the efficient conversion of In2O3 to InN. We find that the nitridation of In2O3 is effective by using NH3 and H2 or a two-step temperature nitridation process using just NH3 and slower ramp rates. We discuss the nitridation mechanism and its effect on the PL.