title: Enhanced ordering in gold nanoparticles self-assembly through excess free ligands.
abstract: Self-assembly of nanometer-sized particles is an elegant and economical approach to achieve dense patterns over large areas beyond the resolution and throughput capabilities of electron-beam lithography. In this paper, we present results of self-assembly of oleylamine-capped gold nanoparticles with 8.0 ± 0.3 nm diameter into densely packed and well-ordered monolayers with center-to-center distance of ∼11 nm. Self-assembly was done in a Langmuir-Blodgett trough and picked up onto Si substrates. The nanoparticles undesirably assembled within micrometer-sized "droplets" that were organic in nature. However, within these droplets, we observed that the addition of the excess ligand, oleylamine, drastically enhanced the self-assembly of the nanoparticles into monolayers with near-perfect ordering. This approach has the potential use in templated self-assembly of nanoparticles for rearranging poorly ordered assembly into a commensurate prepatterned substrate.
authors.affiliation: Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States.
authors.forename: Cindy Y
authors.initials: CY
authors.lastname: Lau
authors.forename: Huigao
authors.initials: H
authors.lastname: Duan
authors.forename: Fuke
authors.initials: F
authors.lastname: Wang
authors.forename: Chao Bin
authors.initials: CB
authors.lastname: He
authors.forename: Hong Yee
authors.initials: HY
authors.lastname: Low
authors.forename: Joel K W
authors.initials: JK
authors.lastname: Yang