The mean inner potential of GaN measured from nanowires using off-axis electron holography


The mean inner potentials of wurtzite GaN nanowires are measured using off-axis electron holography in the transmission electron microscope (TEM). The nanowires have a circular cross-section and are suspended across holes in a holey carbon film, resulting in an accurate knowledge of their thickness profiles and orientations. They are also free of the implantation and damage that is present in mechanically-polished ion-milled TEM specimens. The effect of a thin amorphous coating, which is present on the surfaces of the nanowires, on measurements of their mean inner potential is assessed. A value for the mean inner potential of GaN of (16.7 ± 0.3) V is obtained from these samples.

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ASW and GWH acknowledge the Cambridge Commonwealth Trust. RDB, RAO and PMDFC also acknowledge the the Royal Society, the Royal Commission for the Exhibition of 1851 and the Engineering and Physical Sciences Research Council (EPSRC) for financial support, respectively.

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Correspondence to Andrew S. W. Wong.

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Wong, A.S.W., Ho, G.W., Dunin-Borkowski, R. et al. The mean inner potential of GaN measured from nanowires using off-axis electron holography. MRS Online Proceedings Library 892, 1102 (2005).

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