Atom Probe Tomography of Zinc Oxide Nanowires

作者:Dawahre Nabil*; Shen Gang; Balci Soner; Baughman William; Wilbert David S; Harris Nick; Butler Lee; Martens Rich; Kim Seongsin Margaret; Kung Patrick
来源:Journal of Electronic Materials, 2012, 41(5): 801-808.
DOI:10.1007/s11664-011-1803-x

摘要

Wide-bandgap zinc oxide (ZnO) semiconductors and nanowires have become important materials for electronic and photonic device applications. In this work, we report the growth of well-aligned single-crystal ZnO nanowire arrays on sapphire substrates by chemical vapor deposition and the development of atom probe tomography, an emerging nanoscale characterization method capable of providing deeper insight into the three-dimensional distribution of atoms and impurities within its structure. Using a metal-catalyst-free approach, the influence of the growth parameters on the orientation and density of the nanowires were studied. The resulting ZnO nanowires were determined to be single crystalline, with diameter on the order of 50 nm to 150 nm and length that could be controlled between 0.5 mu m to 20 mu m. Their density was on the order of high 10(8) cm(-2) to low 10(9) cm(-2). In addition to routine characterizations using scanning and transmission electron microscopy, x-ray diffraction, photoluminescence, and Raman spectroscopy, we developed the atom probe tomography technique for ZnO nanowires, comparing the voltage pulse and laser pulse modes. In-depth analysis of the data was carried out to determine the accurate chemical composition of the nanowires and reveal the incorporation of nitrogen impurities. The current-voltage characteristics of individual nanowires were measured to determine their electrical properties.

  • 出版日期2012-5