Supplemental Materials
Surface Plasmon Resonances of Ga Nanoparticle Arrays
M. Kang,1 T. W. Saucer,2 M. V. Warren,1 J. H. Wu,1 H. Sun,1 V. Sih,2 and R. S. Goldman1*
Department of Materials Science and Engineering
Department of Physics
University of Michigan, Ann Arbor, MI 48109-2136, USA
*[email protected]
For transmission electron microscopy (TEM) studies, cross–sectional specimens of Ga
nanoparticle (NP) arrays on GaN surfaces were prepared by ion milling followed by lift-out
processing in a FEI Helios Nanolab 650 FIB. The sample was then mounted on a Mo grid and
ion polished to ~ 100 nm. TEM imaging and selected area diffraction (SAD) were carried out in
a JEOL 3011 operating at 300 kV.
Figure 1 presents (a) a bright-field TEM image and corresponding selected area diffraction
(SAD) patterns collected from (b) a FIB-patterned Ga NP and (c) the GaN substrate, in the
vicinity of the Ga NP. The SAD pattern from the Ga NP, shown in Fig. 1(b), presents a diffuse
ring corresponding to a mean interatomic distance of 2.79 Å, similar to the first nearest neighbor
Ga separation reported for α-Ga, 2.78 Å.1 For the GaN region, Fig. 1(c) reveals a single crystal
pattern with R1/R2 = 1.778 and θR1-R2 = 90°, similar to the [ 1 100] zone axis of a-plane wurtzite
GaN, with R(11 2 0)/R(0001) = 1.779 and θ(11 2 0)-(0001) = 90°.2
Supplemental Figure Caption
Supplemental Fig. 1 (a) Bright-field transmission electron micrograph of a FIB-fabricated Ga
nanoparticle (NP) on a GaN surface; corresponding SAD pattern collected from (b) a Ga NP and
(c) the GaN substrate, in the vicinity of the Ga NP.
Supplemental Fig. 1
A. Bererhi, L. Bosio, and R. Cortes, J. Non-Crystalline Solids 30, 253 (1979).
C. H. Shih, T. H. Huang, R. Schuber, Y. L. Chen, L. Chang, I. Lo, M. M. Chou, and D. M.
Schaadt, Nanoscale Res. Lett. 6, 425 (2011).

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