TY - JOUR
T1 - 1-D Metal Nanobead Arrays within Encapsulated Nanowires via a Red-Ox-Induced Dewetting
T2 - Mechanism Study by Atom-Probe Tomography
AU - Sun, Zhiyuan
AU - Tzaguy, Avra
AU - Hazut, Ori
AU - Lauhon, Lincoln J.
AU - Yerushalmi, Roie
AU - Seidman, David N.
N1 - Funding Information:
D.N.S., L.J.L., A.T., O.H., R.Y., and Z.S. acknowledge partial funding support from the United States−Israel Binational Science Foundation (grant number 2012088). D.N.S., L.J.L., and Z.S. acknowledge the support of Northwestern University’s McCormick School of Engineering and Applied Science. L.J.L. acknowledges support of DMR-1611341. We kindly thank Prof. J. T. Hupp and Dr. W. Hoffeditz for performing atomic layer deposition. APT was performed at the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The local-electrode atom-probe tomography at NUCAPT was acquired and upgraded with equipment grants from the MRI program of the National Science Foundation (grant number DMR-0420532) and the DURIP program of the Office of Naval Research (grant numbers N00014-0400798, N00014-0610539, N00014-0910781). This work made use of the EPIC, Keck-II, and/or SPID facility(ies) of Northwestern University’s NUANCE Center, which received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN.
PY - 2017/12/13
Y1 - 2017/12/13
N2 - Metal nanoparticle arrays are excellent candidates for a variety of applications due to the versatility of their morphology and structure at the nanoscale. Bottom-up self-assembly of metal nanoparticles provides an important complementary alternative to the traditional top-down lithography method and makes it possible to assemble structures with higher-order complexity, for example, nanospheres, nanocubes, and core-shell nanostructures. Here we present a mechanism study of the self-assembly process of 1-D noble metal nanoparticles arrays, composed of Au, Ag, and AuAg alloy nanoparticles. These are prepared within an encapsulated germanium nanowire, obtained by the oxidation of a metal-germanium nanowire hybrid structure. The resulting structure is a 1-D array of equidistant metal nanoparticles with the same diameter, the so-called nanobead (NB) array structure. Atom-probe tomography and transmission electron microscopy were utilized to investigate the details of the morphological and chemical evolution during the oxidation of the encapsulated metal-germanium nanowire hybrid-structures. The self-assembly of nanoparticles relies on the formation of a metal-germanium liquid alloy and the migration of the liquid alloy into the nanowire, followed by dewetting of the liquid during shape-confined oxidation where the liquid column breaks-up into nanoparticles due to the Plateau-Rayleigh instability. Our results demonstrate that the encapsulating oxide layer serves as a structural scaffold, retaining the overall shape during the eutectic liquid formation and demonstrates the relationship between the oxide mechanical properties and the final structural characteristics of the 1-D arrays. The mechanistic details revealed here provide a versatile tool-box for the bottom-up fabrication of 1-D arrays nanopatterning that can be modified for multiple applications according to the RedOx properties of the material system components.
AB - Metal nanoparticle arrays are excellent candidates for a variety of applications due to the versatility of their morphology and structure at the nanoscale. Bottom-up self-assembly of metal nanoparticles provides an important complementary alternative to the traditional top-down lithography method and makes it possible to assemble structures with higher-order complexity, for example, nanospheres, nanocubes, and core-shell nanostructures. Here we present a mechanism study of the self-assembly process of 1-D noble metal nanoparticles arrays, composed of Au, Ag, and AuAg alloy nanoparticles. These are prepared within an encapsulated germanium nanowire, obtained by the oxidation of a metal-germanium nanowire hybrid structure. The resulting structure is a 1-D array of equidistant metal nanoparticles with the same diameter, the so-called nanobead (NB) array structure. Atom-probe tomography and transmission electron microscopy were utilized to investigate the details of the morphological and chemical evolution during the oxidation of the encapsulated metal-germanium nanowire hybrid-structures. The self-assembly of nanoparticles relies on the formation of a metal-germanium liquid alloy and the migration of the liquid alloy into the nanowire, followed by dewetting of the liquid during shape-confined oxidation where the liquid column breaks-up into nanoparticles due to the Plateau-Rayleigh instability. Our results demonstrate that the encapsulating oxide layer serves as a structural scaffold, retaining the overall shape during the eutectic liquid formation and demonstrates the relationship between the oxide mechanical properties and the final structural characteristics of the 1-D arrays. The mechanistic details revealed here provide a versatile tool-box for the bottom-up fabrication of 1-D arrays nanopatterning that can be modified for multiple applications according to the RedOx properties of the material system components.
KW - One-dimensional dewetting
KW - atom-probe tomography
KW - germanium oxide nanowire
KW - hybrid nanostructure
KW - metal nanobeads (NBs)
KW - oxidation
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U2 - 10.1021/acs.nanolett.7b03391
DO - 10.1021/acs.nanolett.7b03391
M3 - Article
C2 - 29116798
AN - SCOPUS:85038210181
VL - 17
SP - 7478
EP - 7486
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 12
ER -