tailieunhanh - Báo cáo hóa học: " Probing Nucleation Mechanism of Self-Catalyzed InN Nanostructures?"

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: Probing Nucleation Mechanism of Self-Catalyzed InN Nanostructures | Nanoscale Res Lett 2010 5 7-13 DOI S11671-009-9434-3 NANO EXPRESS Probing Nucleation Mechanism of Self-Catalyzed InN Nanostructures Guowei Xu Zhuangzhi Li Javier Baca Judy Wu Received 3 June 2009 Accepted 2 September 2009 Published online 16 September 2009 to the authors 2009 Abstract The nucleation and evolution of InN nanowires in a self-catalyzed growth process have been investigated to probe the microscopic growth mechanism of the selfcatalysis and a model is proposed for high pressure growth window at 760 Torr. In the initial stage of the growth amorphous InNx microparticles of cone shape in liquid phase form with assistance of an InNx wetting layer on the substrate. InN crystallites form inside the cone and serve as the seeds for one-dimensional growth along the favorable 0001 orientation resulting in single-crystalline InN nanowire bundles protruding out from the cones. An amorphous InNx sheath around the faucet tip serves as the interface between growing InN nanowires and the incoming vapors of indium and nitrogen and supports continuous growth of InN nanowires in a similar way to the oxide sheath in the oxide-assisted growth of other semiconductor nanowires. Other InN 1D nanostructures such as belts and tubes can be obtained by varying the InN crystallites nucleation and initiation process. Keywords Indium nitride Self-catalyzed Nanowires InNx cones Sheath Introduction Indium nitride InN is currently receiving much attention in large part due to its recently observed narrow band gap of eV 1-3 . The direct band-gap transition in InN and its ability to form ternary ex. InGaN and G. Xu H Z. Li J. Baca J. Wu Department of Physics and Astronomy University of Kansas Lawrence KS 66045 USA e-mail xgw@ quaternary ex. AlInGaN alloys increases the versatility of group-III nitride in optoelectronic devices in a broad spectrum ranging from near IR to UV. InN also has promising transport and electronic properties. It has the smallest effective