Nanosphere lithography

About: Nanosphere lithography is a research topic. Over the lifetime, 1266 publications have been published within this topic receiving 50161 citations.

Nanosphere lithography: A materials general fabrication process for periodic particle array surfaces

Abstract: In this article nanosphere lithography (NSL) is demonstrated to be a materials general fabrication process for the production of periodic particle array (PPA) surfaces having nanometer scale features. A variety of PPA surfaces have been prepared using identical single‐layer (SL) and double‐layer (DL) NSL masks made by self‐assembly of polymer nanospheres with diameter, D=264 nm, and varying both the substrate material S and the particle material M. In the examples shown here, S was an insulator, semiconductor, or metal and M was a metal, inorganic ionic insulator, or an organic π‐electron semiconductor. PPA structural characterization and determination of nanoparticle metrics was accomplished with atomic force microscopy. This is the first demonstration of nanometer scale PPA surfaces formed from molecular materials.

Nanosphere lithography: Tunable localized surface plasmon resonance spectra of silver nanoparticles

Abstract: The wavelength corresponding to the extinction maximum, λmax, of the localized surface plasmon resonance (LSPR) of silver nanoparticle arrays fabricated by nanosphere lithography (NSL) can be systematically tuned from ∼400 nm to 6000 nm. Such spectral manipulation was achieved by using (1) precise lithographic control of nanoparticle size, height, and shape, and (2) dielectric encapsulation of the nanoparticles in SiOx. These results demonstrate an unprecedented level of wavelength agility in nanoparticle optical response throughout the visible, near-infrared, and mid-infrared regions of the electromagnetic spectrum. It will also be shown that this level of wavelength tunability is accompanied with the preservation of narrow LSPR bandwidths (fwhm), Γ. Additionally, two other surprising LSPR optical properties were discovered: (1) the extinction maximum shifts by 2−6 nm per 1 nm variation in nanoparticle width or height, and (2) the LSPR oscillator strength is equivalent to that of atomic silver in gas or...

Chain Length Dependence and Sensing Capabilities of the Localized Surface Plasmon Resonance of Silver Nanoparticles Chemically Modified with Alkanethiol Self-Assembled Monolayers

Abstract: In this paper, we explore the optical properties of Ag nanoparticles chemically modified with alkanethiol self-assembled monolayers (SAMs) by measuring the localized surface plasmon resonance (LSPR) spectrum using UV−vis extinction spectroscopy. For all the experiments presented here, the Ag nanoparticles were fabricated using the technique of nanosphere lithography (NSL) and had in-plane widths of 100 nm and out-of-plane heights of 50 nm. We first demonstrate that unmodified nanoparticles are extremely susceptible to slight changes in 3-dimensional structure when exposed to various solvents. These structural effects can have dramatic effects on the extinction maximum, λmax, of the LSPR shifting it to the blue by over 100 nm. The significant discovery reported here is that λmax for NSL fabricated Ag nanoparticles is extremely sensitive to the SAM properties. We will demonstrate the following new features: (1) λmax of the LSPR linearly shifts to the red 3 nm for every carbon atom in the alkane chain; (2) ...

Wavelength-scanned surface-enhanced Raman excitation spectroscopy.

Abstract: A detailed wavelength-scanned surface-enhanced Raman excitation spectroscopy (WS SERES) study of benzenethiol adsorbed on Ag nanoparticle arrays, fabricated by nanosphere lithography (NSL), is presented. These NSL-derived Ag nanoparticle array surfaces are both structurally well-characterized and extremely uniform in size. The WS SERES spectra are correlated, both spatially and spectrally, with the corresponding localized surface plasmon resonance (LSPR) spectra of the nanoparticle arrays. The surface-enhanced Raman scattering (SERS) spectra were measured in two excitation wavelength ranges: (1) 425−505 nm, and (2) 610−800 nm, as well as with the 532-nm line from a solid-state diode-pumped laser. The WS SERES spectra have line shapes similar to those of the LSPR spectra. The maximum SERS enhancement factor is shown to occur for excitation wavelengths that are blue-shifted with respect to the LSPR λmax of adsorbate-covered nanoparticle arrays. Three vibrational modes of benzenethiol (1575, 1081, and 1009 ...

Metal Nanoparticles: Synthesis, Characterization, and Applications

Abstract: Introduction to particle synthesis, optical, and electronic properties solution-phase nanocluster synthesis and mechanisms of formation magic number metal clusters electrochemical synthesis of high aspect ratio gold particles template synthesis of metal nanostructures synthesis of metal nanoclusters using dendrimer templates nanosphere lithography electrochemistry of monolayer protected gold clusters modelling of nanoparticle optical properties hyper-Raleigh scattering of nanoparticles nanoparticle single electron devices DNA detection using gold nanoparticles conductance-based nanoparticle chemical sensors surface plasmon resonance detection of biomolecules synthesis of conductive polymer-gold particle composites optical properties of complex metal nanostructures si-coated nanoparticles nanoparticle arrays mixed particle arrays nanoparticles in electronic devices.