Safi Jradi

Safi Jradi
Université de Technologie de Troyes | UTT · Physics Materials and Nanotechnologies

Dr.

About

111
Publications
19,632
Reads
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1,097
Citations
Additional affiliations
October 2015 - November 2020
Université de Technologie de Troyes
Position
  • Professor (Associate)
October 2009 - September 2015
Université de Technologie de Troyes
Position
  • Tenure Track
October 2007 - present
Université de Technologie de Troyes
Position
  • tenure Track

Publications

Publications (111)
Article
Full-text available
The integration of nano-emitters into plasmonic devices with spatial control and nanometer precision has become a great challenge. In this paper, we report on the use of a smart polymer to selectively immobilize nano-emitters on specific preselected sites of gold nanocubes (GNCs). The cunning use of the polymer is twofold. First, it records both th...
Article
Full-text available
In this study, we fabricated a hybrid plasmonic/semiconductor material by combining the chemical bath deposition of zinc oxide nanowires (ZnONWs) with the physical vapor depo�sition of aluminum nanostructures (AlNSs) under controlled temperature and atmosphere. The morphological and the optical properties of the ZnONWs/AlNSs hybrid material fabrica...
Poster
Full-text available
In this study, we have successfully fabricated a hybrid plasmonic/semiconductor material by combining the chemical bath deposition of zinc oxide nanowires (ZnONws) and physical vapor deposition of aluminum nanoparticles (AlNps) followed by thermal annealing under controlled atmosphere. The morphological and the optical properties of the ZnONws/AlNp...
Poster
Full-text available
In this work, aluminum nanoparticles (AlNps) were grown on ITO-Quartz substrates by physical vapor deposition (PVD) process followed by thermal annealing under controlled atmosphere. Different thicknesses were treated at different temperatures in order to improve the size and shape of AlNps. Scanning Electron Microscopy (SEM) and Atomic Force Micro...
Patent
Full-text available
The present invention is in the field of surface functionalization of a surface with nano- or microparticles. In particular, the invention concerns a process for functionalizing a surface of a solid support with nano- or microparticles, polymers comprising polymerized amine-functionalized monomer units, their use to functionalize a solid support wi...
Article
Full-text available
This work describes a novel, one-shot strategy to fabricate ultrasensitive SERS sensors based on silver/poly(methyl methacrylate) (PMMA) nanocomposites. Upon spin coating of a dispersion of PMMA and silver precursor on N-doped silicon substrate, closely separated silver nanoparticles were self-assembled into uniform nanospheres. As a result, a thin...
Article
Full-text available
One of the key issues for SERS-based trace applications is engineering structurally uniform substrates with ultrasensitivity, stability, and good reproducibility. A label-free, cost-effective, and reproducible fabrication strategy of ultrasensitive SERS sensors was reported in this work. Herein, we present recent progress in self-assembly-based syn...
Article
Full-text available
In microscale optoelectronics, the possibility to precisely control the spatial distribution of the active medium allows for the optimization of systems and devices. At the nanoscale, this issue still constitutes a challenge. In particular, in hybrid plasmonic nano-emitters based on the combinaison between quantum emitters and localized plasmonic m...
Preprint
Full-text available
Hybrid plasmonic nanoemitters based on the combination of quantum dot emitters (QD) and plasmonic nanoantennas open up new perspectives in the control of light. However, precise positioning of any active medium at the nanoscale constitutes a challenge. Here, we report on the optimal overlap of antenna's near-field and active medium whose spatial di...
Article
Full-text available
Hybrid plasmonic nano-emitters based on the combination of quantum dot emitters (QD) and plasmonic nanoantennas open up new perspectives in the control of light. However, precise positioning of any active medium at the nanoscale constitutes a challenge. Here, we report on the optimal overlap of antenna’s near-field and active medium whose spatial d...
Article
The optical properties of a monolayer of nanocomposite film (PMMA/gold nanocubes) were provided by fitting a proposed theoretical model to spectroscopic ellipsometry (SE) measurements. For such thin film, these features cannot be successfully determined by means of experimental and conventional effective medium theory such as Maxwell-Garnett or Bru...
Presentation
In this work, different sizes and thicknesses of zinc oxide nanowires (ZnO-NWs) were synthetized by hydrothermal method and functionalized by aluminum nanoparticles (ALNPs). The ALNPs were deposited by physical vapor deposition followed by thermal annealing. Structural and optical characterizations were performed using SEM, DRX, UV-visible spectros...
Article
Here, we introduce a mechanistic study to design the hybrid junction in metallic‐semiconductor (M/SC) nanostructures. UV light induced hot electrons generation in ZnO nanostructures is precisely tuned the photoluminescence (PL) and photocatalytic (PC) properties in hybrid Au/ZnO nanomaterials. Both, enhancement and quenching of the PL and PC functi...
Preprint
Full-text available
Quantum dots optically excited in close proximity to a silver nanowire can launch nanowire surface plasmons. The challenge related to this promising hybrid system is to control the position of nanoemitters on the nanowire. We report on the use of two-photon photopolymerization process to strategically position quantum dots on nanowires at controlle...
Data
This is a research article about microfocusing effect generated by a pair of dielectric diffractive scatterers. It's shown that the scattered waves generate a quadratic phase modulation on the total propagating field leading to a diffraction-limited focusing i.e. an effective optical lens effect with high numerical aperture. It's also shown that fo...
Article
Full-text available
In this article, we demonstrate the feasibility of self-positioning nanoemitters onto optical waveguides by visible-light nanoscale photopolymerization. A light-sensitive material containing nanoemitters is photopolymerized at interfaces by using the evanes- cent field of the light propagating in photonic structures. By exploiting this method, it i...
Article
Full-text available
Diffractive approaches are needed when refractive microlenses reach their focusing limit at the micron-scale in visible light. Previously, we have reported on micron-sized optical lenses based on the diffraction of metallic nanowires. Here, we extend our study to lenses based on pairs of subwavelength dielectric scatterers. Using simulations by two...
Article
Full-text available
Quantum dots optically excited in close proximity to a silver nanowire can launch surface plasmons. The challenge related to this promising hybrid system is to control the position of nanoemitters on the nanowire. We report on the use of a two-photon photopolymerization process to strategically position quantum dots on nanowires at controlled sites...
Article
Full-text available
Here, we demonstrate for the first time a strategy to self-assemble ZnO nanoparticles (NP) on a large area by a facile one-step process. First, rough and random ZnO nanocrystals (NC), were produced by free-stabilizing aqueous synthesis. Therefore, a post thermal treatment at various temperatures ranging from 80 to 800 °C was necessary to obtain siz...
Article
In this work, we highlight the feasibility of new efficient catalytic processes by laser excitation, exemplified in the reaction of oxidation of glycerol over catalysts based on supported gold nanoparticles. We show that this catalytic oxidation reaction can efficiently proceed via laser excitation of surface plasmon resonance of gold nanoparticles...
Article
Full-text available
We show Femtosecond direct laser induced assembly of gold nanostructures with plasmon resonance band variable as a function of laser irradiation in a wide range of visible wavelengths. A system of 2-photon lithography is used to achieve site-selectively controlled dewetting of thin gold film into nanostructures where size and shape are highly depen...
Article
Quantum dots (QDs) films or layers are extensively used for various photonic and electronic applications since recent decades. Three‐dimensional (3D) nanostructures are the elegant fashion in micro‐optics, microfluidics, biomedicine, and imaging. In particular, 3D photoluminescent nanostructures play an important role in detection and sensing as we...
Poster
Best poster at the 3rd Edition of international Conference and Exhibitionon Polymer Chemistry, held during 26-28 Mars, 2018, in Vienna, Austria.
Article
Full-text available
Here, we report for the first time a facile and fast one-step strategy to fabricate monodisperse gold nanocubes (GNCs) by spin-coating of a gold precursor-loaded PMMA dispersion on N-doped silicon. A vapor induced phase separation allows the PMMA self-assembly into a nanoporous film including the GNCs in its holes. A control of size and shape until...
Article
A new methodology is developed to determine the shape distribution of gold nanoparticles (NPs) from optical spectroscopic measurements. Indeed, the morphology of Au colloids is deduced by fitting their absorption spectra with an effective medium theory which takes into account the nanoparticle shape distribution. The same procedure is applied to el...
Article
Full-text available
We report on the realization of functional infrared light concentrators based on a thick layer of air-polymer metamaterial with controlled pore size gradients. The design features an optimum gradient index profile leading to light focusing in the Fresnel zone of the structures for two selected operating wavelength domains near 5.6 and 10.4 μm. The...
Article
Full-text available
A new approach for surface nanostructuring was innovated by means of metallic nanoparticles organized in a thin homopolymer film (PMMA) on a silicon substrate. The originality of this simple self-assembly is that a film of polymer drilled by metallic nanoparticle (MNP) rings was fabricated in one step, in addition no reducing agent was used nor was...
Article
In this study, adsorption capacities of uremic toxins over Faujasite (HFAU) and Beta (HBEA) have been evaluated by varying the composition of solvent by using water, physiological and sodium chloride solutions. HFAU was found to be more efficient in adsorption of these molecules. The adsorption results over HFAU were compared in various conditions...
Article
Full-text available
This paper reports the complete ellipsometric characterization of gold nanoparticles (NPs) embedded in a photoresist films. The effective dielectric function of nanocomposite films as well as the shape distribution and the volume fraction of NPs are extracted from ellipsometric measurements by introducing an effective medium theory which takes into...
Article
The preparation method of porous PMMA containing silver nanoparticles self-assembled in rings is highly adaptable, yielding a variety of materials of controllable pore size (ranging from 200 nm to over 5 µm), nanoparticle size (20 to 200 nm), surface coverage and silver precursor concentration. In this article, it is optimized aiming at a best perf...
Article
A strong interest exists in developing surfaceenhanced Raman spectroscopy (SERS) substrates that uniformly enhance Raman signals of chemical and biological molecules over large scales while reaching the detection limit of trace concentrations. Even though the resonant excitation of localized surface plasmons of single or assembled metallic nanopart...
Article
A strong interest exists in developing Surface-Enhanced Raman Spectroscopy (SERS) substrates that uniformly enhance Raman signals of chemical and biological molecules over large scales while reaching the detection limit of trace concentrations. Even though the resonant excitation of localized surface plasmons of single or assembled metallic nanopar...
Article
Full-text available
We demonstrate two-color nano-emitters that enable the selection of the dominant emitting wavelength by varying the polarization of excitation light. The nano-emitters were fabricated via surface plasmon-triggered two-photon polymerization. By using two polymerizable solutions with different quantum dots, emitters of different colors can be positio...
Patent
Full-text available
The present disclosure relates to a method for manufacturing end microlenses of individual optical fibers which are part of a bundle or a multi-core fiber, including depositing a drop of a photopolymerizable solution on a first end of the bundle; adapting the size of the drop; applying light centered on a predetermined wavelength onto a second end...
Article
During holographic recording, interference patterns produced by a reference beam and the light waves scattered by the object are stored by building-up of refractive index variations or relief profiles in the photosensitive medium. Early holograms used silver halide photographic emulsions as the recording medium. Being able to memorize an incident c...
Article
Full-text available
Hybrid nanomaterials are targeted by a rapidly growing group of nanooptics researchers, due to the promise of optical behavior that is difficult or even impossible to create with nanostructures of homogeneous composition. Examples of important areas of interest include coherent coupling, Fano resonances, optical gain, solar energy conversion, photo...
Article
Full-text available
Fabrication of freestanding, three-dimensional microstructures having gold nanoparticles as building blocks has been achieved using two-photon lithography. The reported constructions hold structural coherence without the need of a polymeric network to embed the nanoparticles. The Au nanoparticles are produced by radical-mediated photoreduction and...
Article
Full-text available
In numerous applications of optical scanning microscopy, a reference tapered fiber lens with high symmetry at sub-wavelength scale remains a challenge. Here, we demonstrate the ability to manufacture it with a wide range of geometry control, either for the length from several hundred nanometers to several hundred microns, or for the curvature radiu...
Chapter
Achieving topography and chemistry control at the nanoscale of polymer surfaces constitutes a highly challenging objective in nanotechnology. Advances in this field suppose the development of characterization methodology with sub-100-nm resolution. Many imaging techniques based on scanning probe microscopy (SPM) were recently developed to achieve t...
Article
Full-text available
High-throughput, simple nanofabrication methods are essential keys for involving plasmonic materials with large electric fields for practical applications. We demonstrate in this paper a facile route for fabricating multifunctional metallic nanomaterials for sensing, which is particularly relevant to SERS spectroscopy. A simple deposition of a poly...
Article
Pointed carbon nanotips have been deposited on polymer microlensed optical fibers and used as highly resolving scattering nanoprobes. Optical characterizations supported by simulations demonstrate an efficient spatial filtering where the light scattered by the carbon tip is selectively coupled into the fiber core. As an application, a channel surfa...