Jun 1, 2011
LANE team engineers fast growth of branched nickel monosilicide nanowires
Self-organized hierarchical one-dimensional nanostructures, called branched nanostructures, have attracted much attention because of their structural complexity and novel electronic and photonic functionality. In a recent study performed by researchers at the University of Nebraska-Lincoln (UNL), US, branched nickel monosilicide (NiSi) nanowires (NWs) have been synthesized on nickel foams by laser-assisted chemical vapour deposition (LCVD) using disilane (Si2H6) molecules as the precursor. Investigations of these branched NiSi NWs suggest that the nickel diffusion process contributes to their formations.
As shown in the figure, the branched NiSi nanowires consist of branches extending from stems. The branches grow nearly perpendicular to the stem, tapering from the large stem-branch junctions to the branch tips with diameters of 5–10 nm.
The atomic ratio of nickel and silicon changes from 1.25:1 at the stems to 0.37:1 at the branches, indicating a gradual depletion of nickel content from the stems to the branches. The growth rate of branched NiSi NWs is estimated at up to 10 µm min–1.
The team believes that NiSi NWs with branched nanostructures could open up new opportunities in nanodevices.
The researchers presented their work in the journal Nanotechnology.
About the author
The work was performed at the UNL and supported by the National Science Foundation, US. Yang Gao, Zhiqiang Xie and Wei Xiong are currently pursuing their PhD degrees in the Laser-Assisted Nano-Engineering (LANE) Laboratory at UNL under the supervision of Prof. Yongfeng Lu. Dr Yunshen Zhou is a research assistant professor in the Department of Electrical Engineering at UNL. Prof. Lan Jiang and Dr Huifu Luo are from the Department of Mechanical and Automation Engineering at the Beijing Institute of Technology. Min Qian is a visiting student from the Department of Physics at East China Normal University. Prof. Yongfeng Lu, the Lott Professor of Engineering at UNL, is the primary investigator of the programme and leader of the LANE laboratory.