Search results for "Nanofabrication"

Rayleigh-instability-driven dewetting of thin Au and Ag films on indium-tin-oxide surface under nanosecond laser irradiations

2013

Investigations have been carried out on laser-beam-induced nanoparticle (NP) formation in thin (5 nm) Au and Ag films on indium-tin-oxide substrate. After the irradiation the films were observed to break-up into NPs through a dewetting mechanism. This mechanism was investigated as a Rayleigh-instability- driven process. In fact, for each used laser fluence, the resulting Au and Ag NPs' mean size and surface-to-surface mean distance were quantified and correlated between them in the framework of the Rayleigh-instability theory showing an excellent agreement. © The Institution of Engineering and Technology 2013.

Single quantum dot emission at telecom wavelengths from metamorphic InAs/InGaAs nanostructures grown on GaAs substrates

2011

3 figuras, 3 páginas.

Biomineral Amorphous Lasers through Light-Scattering Surfaces Assembled by Electrospun Fiber Templates

2018

New materials aim at exploiting the great control of living organisms over molecular architectures and minerals. Optical biomimetics has been widely developed by microengineering, leading to photonic components with order resembling those found in plants and animals. These systems, however, are realized by complicated and adverse processes. Here we show how biomineralization might enable the one-step generation of components for amorphous photonics, in which light is made to travel through disordered scattering systems, and particularly of active devices such as random lasers, by using electrospun fiber templates. The amount of bio-enzymatically produced silica is related to light-scatterin…

Fabrication, Electrical Characterization and 1/f Noise Study of Submicron-sized Superconducting Tunnel Junctions

2016

Contrôle de nano-antennes optiques par une commande électrique : tuner plasmonique et transduction

2011

Optical nano-antennae are the new class of components to control light/matterinteraction at the nanoscale. These devices are operating in the visible to near infraredpart of the spectrum. The properties of these nano objects are controlled by theform, the size and the material.In the radio frequency domain, the tuner changes dynamically the operatingwavelength of the antenna. In this thesis work, we search to transfer this conceptto the nanoscale. The principle is to change the load impedance of the antenna, i.e.changing the optical index of the dielectric medium around the nano-object. Forthat we used anisotropic liquid cristal molecules. The value of the optical index iscontrolled by appl…

Laser-Fabricated Fluorescent, Ligand-Free Silicon Nanoparticles: Scale-up, Biosafety, and 3D Live Imaging of Zebrafish under Development

2022

This work rationalizes the scalable synthesis of ultrasmall, ligand-free silicon nanomaterials via liquid-phase pulsed laser ablation process using picosecond pulses at ultraviolet wavelengths. Results showed that the irradiation time drives hydrodynamic NP size. Isolated, monodisperse Si-NPs are obtained at high yield (72%) using post-treatment process. The obtained Si-NPs have an average size of 10 nm (not aggregated) and display photoemission in the green spectral range. We directly characterized the ligand-free Si-NPs in a vertebrate animal (zebrafish) and assessed their toxicity during the development. In vivo assay revealed that Si-NPs are found inside in all the early life stages of …

Photoconductive properties of Bi2S3nanowires

2015

The photoconductive properties of Bi2S3 nanowires synthesized inside anodized alumina (AAO) membrane have been characterized as a function of illuminating photon energy between the wavelengths of 500 to 900 nm and at constant illumination intensity of 1–4 μW·cm−2. Photoconductivity spectra, photocurrent values, photocurrent onset/decay times of individual Bi2S3 nanowires liberated from the AAO membrane were determined and compared with those of arrays of as-produced Bi2S3 nanowires templated inside pores of AAO membrane. The alumina membrane was found to significantly influence the photoconductive properties of the AAO-hosted Bi2S3 nanowires, when compared to liberated from the AAO membrane…

Well-aligned hydrothermally synthesized zinc oxide nanorods on p-GaN without a seed layer

2015

Zinc oxide nanorods have great potential for the realization of high efficiency heterostructure LEDs based on pdoped gallium nitride. In order to obtain a good confinement of the light, a well-aligned nanorod waveguiding structure is desirable. This paper reports on the fabrication of vertical zinc oxide nanorods using a solution-based growth process that does not require a seed layer. The nanorods obtained follow the crystalline growth direction of the GaN layer along the c-axis. Various results with different reagent concentrations are reported.

Nanofabrication on 2D and 3D Topography via Positive‐Tone Direct‐Write Laser Lithography

2019

Direct laser writing (DLW) lithography using two‐photon absorption is a powerful technique mostly used for fabrication of complex structures in micro‐ and nanoscale, by photopolymerizing a negative‐tone resist. In contrast, in this study it is demonstrated that DLW is also well suited for fabricating nano‐ to microscale metallic structures using lift‐off and a positive‐tone photoresist. It is shown first that versatile, fast and large area fabrication is possible on flat two‐dimensional insulating substrates, and an expression for how the line width varies with the scanning speed is derived, with excellent agreement with the experiments. Even more interestingly, a unique application for the…

Dielectrophoretic trapping of multilayer DNA origami nanostructures and DNA origami-induced local destruction of silicon dioxide

2015

DNA origami is a widely used method for fabrication of custom-shaped nanostructures. However, to utilize such structures, one needs to controllably position them on nanoscale. Here we demonstrate how different types of 3D scaffolded multilayer origamis can be accurately anchored to lithographically fabricated nanoelectrodes on a silicon dioxide substrate by DEP. Straight brick-like origami structures, constructed both in square (SQL) and honeycomb lattices, as well as curved "C"-shaped and angular "L"-shaped origamis were trapped with nanoscale precision and single-structure accuracy. We show that the positioning and immobilization of all these structures can be realized with or without thi…