Assembly of silver nanoparticles on nanowires into ordered nanostructures with femtosecond laser radiation

Abstract

In this work, we show that well-ordered structures of silver nanoparticles on nanowire substrates can be produced by irradiation with femtosecond (fs) laser pulses at fluences ranging from 10.3 to 15.9 mJ/cm² if the direction of polarization is parallel to the long axis of the nanowire. Experimental results show that a uniformly spaced distribution of nanoparticles is more readily produced on nanowires with lengths L≤2λ, where λ=800 nm is the laser wavelength. The distribution of nanoparticles is found to become less well organized as L≥2λ. Finite element method simulations, combined with experimental observations, indicate that nanoparticles are initially distributed in response to the electric field along the clean Ag nanowire arising from optical excitation. This electric field is responsible for the attraction of nanoparticles to certain locations on the nanowire. We show how a fs-laser-driven assembly of nanoparticles on nanowires can be used in the development of a nanoscale optical logic processor. This method of creating periodic arrays of metallic nanoparticles on nanowire substrates then has many possible applications in electro-optics.

Macroscopic Alignment of Silver Nanoplates in an Adaptable Dichroic Polarizer

“…In order for this color change to occur, the majority of the Ag-NPLs would have to be anisotropically oriented, on average, within the polymer; thus, the two separate plasmon bands (longitudinal and transverse) exhibit a non-uniform response to the polarized light. Multiple axial-dependent plasmonic bands have been observed previously for ansiotropic particles including nanorice [1], nanowires [9], and nanorods [26]. Similar dichroic polarization behavior was observed by Dirix et al for composites containing oriented pearl necklace arrays; however, these arrays were produced in situ and lack the optical and morphological tractability that our method provides [6].…”

“…Due to their dichroic nature and facile synthesis, ellipsoidal silver nanoparticles (Ag-NPs), including so-called nanorice [1], nanocarrots [2], nanorods [3], and nanoplates [4], are excellent candidates for the design of devices with controlled absorption of light. Specific control of the assembly and orientation of Ag-NPs has led to the development of polarizing films [5][6][7][8], nano-antennas [9], dichroic optical filters [6,10], and surface-enhanced Raman substrates [11]. Oriented arrays of Ag-NPs can be difficult and expensive to fabricate in large reproducible quantities and are limited in their tractability over the optical properties.…”

Formation Mechanism and Fluorescence Characterization of a Transient Assembly of Nanoparticles Generated by Femtosecond Laser Trapping

“…Through combination of two lasers with different wavelengths as a trapping laser and heating source, fs laser trapping can be used to probe the temperature of particles in solution . Moreover, a nanostructure can be built by a combination of optical force and nonlinear effect of the fs laser, which breaks through the diffraction limitation. , Irradiating the fs laser on metal nanowires generates a plasmon, which induces force to attract nanoparticles. , Fs trapping is receiving much attention as a potential tool in chemistry and material science or in biological science, and its studies or dynamics and mechanism are strongly requested.…”

“…17,18 Irradiating the fs laser on metal nanowires generates a plasmon, which induces force to attract nanoparticles. 19,20 Fs trapping is receiving much attention as a potential tool in chemistry and material science or in biological science, and its studies or dynamics and mechanism are strongly requested.…”

Fabrication of large‐area ordered array of gold nanoparticles on c‐Si substrate and its characterisation through reflectance spectra

“…Introduction: Array of Au NPs (gold nanoparticles) is a much sought after structure having a wide range of applications in photovoltaics [1], surface enhanced fluorescence [2], bio sensing [3], label-free visualisation of living cells [4], magnetic memory and so on. Different processes are available to fabricate an array of Au NPs such as focused ion beam fabrication [5], femtosecond laser irradiation [6], thermal dewetting [7][8][9], nanoplastic forming with thermal dewetting [10][11][12][13] and so on. However, most of these processes results in random sized nanoparticles (NPs) and their position are also random and/or it is difficult to achieve over a larger area.…”