tailieunhanh - Báo cáo hóa học: " Synthesis and Characterization of Glomerate GaN Nanowires"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Synthesis and Characterization of Glomerate GaN Nanowires | Nanoscale Res Lett 2009 4 584-587 DOI s11671-009-9285-y NANO EXPRESS Synthesis and Characterization of Glomerate GaN Nanowires Lixia Qin Chengshan Xue Yifeng Duan Liwei Shi Received 21 October 2008 Accepted 4 March 2009 Published online 17 March 2009 to the authors 2009 Abstract Glomerate GaN nanowires were synthesized on Si 111 substrates by annealing sputtered Ga2O3 Co films under flowing ammonia at temperature of 950 C. X-ray diffraction scanning electron microscopy high resolution transmission electron microscopy and Fourier transformed infrared spectra were used to characterize the morphology crystallinity and microstructure of the as-synthesized samples. Our results show that the samples are of hexagonal wurtzite structure. For the majority of GaN nanowires the length is up to tens of microns and the diameter is in the range of 50-200 nm. The growth process of the GaN nanowires is dominated by Co-Ga-N alloy mechanism. Keywords Nanowires Magnetron sputtering Alloy mechanism Introduction Gallium nitride GaN has gained considerable attentions due to its wide and direct band gap eV at room temperature high thermal stability and strong resistance to radiation 1-5 . GaN-based materials are expected to be a good candidate for high-power electronic devices lightemitting diodes and laser diodes in the blue and UV wavelength regions 6-8 . In recent years more and more research efforts have been devoted to the one-dimensional nanoscale materials because of their fascinating electronic optical and mechanical properties in fabrication of novel nanodevices 9-12 . The GaN nanowires are of interest due to the giant electrogyration effects 13 . Many attempts have been made to synthesize GaN nanowires using various techniques such as the carbon-nanotube-confined reaction the anodic alumina template method arc discharge laser ablation catalytic chemical vapour deposition and the oxide-assisted growth route 14-26 . Compared to these techniques the radio frequency RF