Ultrasmooth, highly spherical monocrystalline gold particles for precision plasmonics.
Ultrasmooth, highly spherical monocrystalline gold particles were prepared by a cyclic process of slow growth followed by slow chemical etching, which selectively removes edges and vertices. The etching process effectively makes the surface tension isotropic, so that spheres are favored under quasi-static conditions. It is scalable up to particle sizes of 200 nm or more. The resulting spherical crystals display uniform scattering spectra and consistent optical coupling at small separations, even showing Fano-like resonances in small clusters. The high monodispersity of the particles we demonstrate should facilitate the self-assembly of nanoparticle clusters with uniform optical resonances, which could in turn be used to fabricate optical metafluids. Narrow size distributions are required to control not only the spectral features but also the morphology and yield of clusters in certain assembly schemes.
Department of Polymer Science and Engineering and School of Chemical Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
You-Jin
YJ
Lee
Nicholas B
NB
Schade
Li
L
Sun
Jonathan A
JA
Fan
Doo Ri
DR
Bae
Marcelo M
MM
Mariscal
Gaehang
G
Lee
Federico
F
Capasso
Stefano
S
Sacanna
Vinothan N
VN
Manoharan
Gi-Ra
GR
Yi