Lazhar Lalaoui

Université Ferhat Abbes Setif, Institute of Optics and Precision Mechanics, Post-Doc

Followers

Following

Public Views

I am currently a Ph.D Student at the Institute of Optics and Precision Mechanics, University of Setif. My research interests are Engineering Optics, Fluorescence Correlation Spectroscopy and also solar cell efficiency. My most recent publication is 'Axial Point Spread Function Modeling by Application of Effective Medium Approximations: Widefield Microscopy'.

less

Interests

Uploads

Papers by Lazhar Lalaoui

Scattering Correlation Spectroscopy and Raman Spectroscopy of Thiophenol on Gold Nanoparticles: Comparative Study between Nanospheres and Nanourchins

The Journal of Physical Chemistry C, 2017

A surface characterization of branched and spherical gold nanoparticles was done by two complemen... more A surface characterization of branched and spherical gold nanoparticles was done by two complementary techniques: scattering correlation spectroscopy (SCS) and surface enhanced Raman spectroscopy (SERS). Thiophenol was used as a surface marker to probe the surface area and the gold-thiophenol interaction in gold nano-urchins (GNU) and gold nano-spheres (GNS). We have observed that for GNU, the thiophenol is first grafted on the core, with a saturation concentration around 10-3 M as observed for GNS. Afterwards, the saturation of the branches occurs at higher thiophenol concentration (~1 M). A numerical calculation of the surface area of different sizes of GNS allowed us to estimate the GNU surface area. The hydrodynamic radius was measured at different steps of thiophenol-GNP functionalization. By comparing spherical and non-spherical nanoparticles, we demonstrate that the molecules-GNP interaction is highly dependent on the nanoparticles morphology (size and shape). 10,34-35 While, electronic microscopy has the disadvantage of consuming a lot of time for GNP characterization, an attractive alternative is dynamic light scattering, 36-37 although it is difficult to get a high spatial resolution and further physical properties. Recently, correlation spectroscopy has been demonstrated to be one of the most fast and sensitive techniques used for GNP size and surface chemistry characterization. 38-40 Correlation spectroscopy using fluorescence (FCS) or scattering (SCS) signals was especially used to characterize GNP interaction with various molecules as fluorescent markers, 41-44 polymers 45-46 or proteins. 47 Recently, correlation spectroscopy was associated to SERS in many studies for nanoparticles-molecules interaction chemical characterization. 48-49 In this latter, thiophenol (TP) is one of the most studied SERS-active molecules to characterize GNPs, due to the strong affinity of thiols to form covalent bonds with gold surface and the ability of the aromatic cycle to produce strong SERS spectra. 50-51 In

Download

Indoor and Outdoor Measurements of PV Module Performance of Different Manufacturing Technologies

In the present paper, an experimental analysis of the PV modules efficiency of different photovol... more In the present paper, an experimental analysis of the PV modules efficiency of different photovoltaic comprising monocrystalline silicon, polycrystal-line silicon and thin-film silicon technologies has been made. The PV modules were first subjected to thorough indoor evaluation (Sun simulator, Electroluminescence) to check the real characteristics and internal defects that make the effectiveness of these modules lower compared to characteristics declared by the manufacturer under the terms of DIN EN ISO/IEC 17025:2005. Results of the first analysis have been taken as a reference for the second part, which consist of ex-posing the PV modules to various natural factors in outdoor environment (solar radiation, temperature, wind, humidity…) versus time. Then, using the peak power measuring device PVPM, different electrical characteristics of the photovoltaic module during the exposure in operating site were determined. Significant differences in the energy efficiency of PV modules have ...

Download

Axial Point Spread Function Modeling by Application of Effective Medium Approximations: Widefield Microscopy

Optik

$Research paper thumbnail of Refractive effects of the Gaussian beam on the volume confinement for fluorescence correlation spectroscopy: Experimental and numerical study$

Refractive effects of the Gaussian beam on the volume confinement for fluorescence correlation spectroscopy: Experimental and numerical study

Optik - International Journal for Light and Electron Optics

Scattering Correlation Spectroscopy and Raman Spectroscopy of Thiophenol on Gold Nanoparticles: Comparative Study between Nanospheres and Nanourchins

The Journal of Physical Chemistry C, 2017

Download

Indoor and Outdoor Measurements of PV Module Performance of Different Manufacturing Technologies

Download

Axial Point Spread Function Modeling by Application of Effective Medium Approximations: Widefield Microscopy

Optik

$Research paper thumbnail of Refractive effects of the Gaussian beam on the volume confinement for fluorescence correlation spectroscopy: Experimental and numerical study$

Refractive effects of the Gaussian beam on the volume confinement for fluorescence correlation spectroscopy: Experimental and numerical study

Optik - International Journal for Light and Electron Optics

Lazhar Lalaoui

Uploads

Papers by Lazhar Lalaoui

Log In