Paper NS-ThM1
Depth Resolved Luminescence from ZnO Nanowires
Thursday, November 12, 2009, 8:00 am, Room L
| Session: |
Characterization and Imaging at the Nanoscale |
| Presenter: |
R.A. Rosenberg, Argonne National Laboratory |
| Authors: |
R.A. Rosenberg, Argonne National Laboratory
S. Vijayalakshmi, Argonne National Laboratory
M. Abu Haija, Argonne National Laboratory
J. Zhou, Georgia Institute of Technology
J. Liu, Georgia Institute of Technology
S. Xu, Georgia Institute of Technology
Z.L. Wang, Georgia Institute of Technology
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| Correspondent: |
Click to Email |
Nanodevices based on wide bandgap semiconductors have great potential in applications running from photon detectors to gas sensors. Critical to their successful implementation is knowledge of the surface and interfacial properties. In the present work we have utilized the limited penetration depth of soft x-rays (550-1000 eV) to study the near surface properties of vertically aligned ZnO nanowires. For a grazing angle of 5 degrees the penetration depth of these x-rays varies between 11 and 65 nm. Thus by obtaining optical luminescence spectra as a function of energy it is possible to probe the near surface region with nm-scale resolution. We will present energy dependent optical luminescence data from ZnO nanowire samples with diameters of 350 nm, 390 nm and 720 nm. In each case the ratio of the oxygen vacancy luminescence to the near band edge luminescence intensity peaks at an energy corresponding to ~17 nm x-ray penetration. This shows that the nanowires of three different diameters have a near surface defect region with a width of ~20 nm, which agrees with the conclusions from previous photoluminescence and cathodoluminescence studies [1-3]. Applications of this technique to other systems will also be discussed.This work was performed at the Advanced Photon Source and was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-06CH11357.
REFERENCES
[1] N. Pan et al., J. Phys. Chem. C 111, 17265 (2007).
[2] I. Shalish, H. Temkin, and V. Narayanamurti, Phys. Rev. B 69, 245401 (2004).
[3] J. D. Ye et al., App. Phys. Lett. 92, 131914 (2008).