Azizollah Shafiekhani

Azizollah Shafiekhani
Alzahra University · Department of Physics

Professor

About

114
Publications
24,176
Reads
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1,590
Citations
Introduction
Azizollah Shafiekhani received his Ph. D. in Physics from department of Physics, Sharif University of Technology, Tehran, Iran. He held his BSc and MSc in the same department. His current research interest has focused on “Nanophysics in general”.
Additional affiliations
September 2002 - present
Alzahra University
Position
  • Faculty Member
June 1994 - present
Institute for Research in Fundamental Sciences (IPM)
Position
  • Researcher
Education
September 1990 - August 1994
Sharif University of Technology
Field of study
  • Physics

Publications

Publications (114)
Article
Full-text available
In this study, we investigated the morphology of synthesized Cu/Ni nanoparticles in trace of carbon sources by the co-deposition process of RF sputtering and RF-PECVD methods and localized surface plasmon resonance of CO gas sensing of Cu/Ni nanoparticles. The surface morphology was studied by analyzing 3D micrographs of atomic force microscopy usi...
Preprint
The effect of a bilayer of different dimension silver nanoparticles (Ag NPs) on light trapping in silicon solar cells is investigated. Here, we report on the improved performance of silicon solar cells by integrating two layers of silver nanoparticles of different sizes. We experimentally examine the plasmonic near-field and far-field effects of bi...
Article
We introduce a study of image analysis of kefir biofilms associated with Acai extract prepared by fermentation of fresh kefir grains natural. Atomic force microscopy data were studied, aiming to understand how the concentration of acai berry (Euterpe oleracea Mart.) influences the surface morphology as well as the texture complexity, evaluated by t...
Conference Paper
Cobalt nanoparticles were replaced in Diamond-like Carbon by radiofrequency sputtering (RF- Sputtering) and radio frequency plasma enhanced chemical vapor deposition (RF-PECVD), respectively. Then ultraviolet-visible-near-infrared spectroscopy was performed on these samples. Information obtained from analyzes such as atomic force microscopy (AFM)...
Article
The aim of the present study is to verify how alternations of annealing temperatures modify optical and micromorphological properties of n-ZnO/p-NZO and n-ZnO/p-NiO multilayers. As can be seen, the optical analysis of homojunctions and hetrojunction thin films shows a red shift by increasing annealing temperature which means that annealing can shif...
Article
Quantum Dots Sensitize Solar Cells (QDSSCs) using photoanodes of porous titanium dioxide with CdS quantum dots are fabricated, and Au Nanoparticles (NPs) within a Diamond-Like Carbon (DLC) are doped. The overall power conversion efficiency (PCE) and short-circuit current density (Jsc) of 2.18% and 7.85 (mA/cm²) are being obtained, respectively. For...
Article
Findings regarding the application of gas sensing on graphene-based material have led to a jump in nanotechnology. Hence, producing high-efficiency materials in this technology is a priority. Recent development in graphene-based material shows that it can be a good candidate for this target. With this in mind, we theoretically studied the effect of...
Article
Full-text available
Delafossite CuFeO2 (CFO) has attracted much attention as a candidate p-type photocathode for photoelectrochemical (PEC) solar hydrogen production. In this paper first, a detailed electrochemical study was carried out in order to determine the best potential range for the potentiostatic deposition of nanostructured CFO on FTO glass. The structural a...
Article
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The current rechargeable battery technologies have a failure in their performance at high pressure and temperature. In this article, we have brought theoretical insights on using boron nitride flakes as a protecting layer for a lithium-ion battery device and extended its application for a spin-dependent photon emission device. Hence, the electronic...
Article
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The main goal of the present work is to explore the three dimensional (3‐D) atomic force microscopy (AFM) images of human teeth and investigating their micromorphology. For this purpose, 10 fresh and permanent canine teeth were selected from a group of 40‐year‐old men who were candidate for the experimental processes. Afterward, they were all appli...
Article
Full-text available
The objective of this study is the experimental investigation of the silver in diamond-like carbon (Ag/DLC) nanocomposite prepared by the co-deposition of radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) and RF-sputtering. Atomic force microscopy (AFM), X-ray diffraction analyses, ultraviolet–visible (UV–visible) spectroscopy me...
Article
Textile industry produces huge amounts of wastewater containing synthetic dyes and impurities. Contaminants include toxic dyes, which can be found in dyeing wastewater. In textile industry, various dyes such as acid, basic, reactive, disperse are used for dyeing. The aim of this study was to evaluate adsorption of Acid Blue 74 by electrospun PA-6/M...
Article
Full-text available
Accuracy and speed of detection, along with technical and instrumental simplicity, are indispensable for the bacterial detection methods. Porous silicon (PSi) has unique optical and chemical properties which makes it a good candidate for biosensing applications. On the other hand, lectins have specific carbohydrate-binding properties and are inexpe...
Article
Full-text available
Hydrogen sensing property of composite films of camphorsulfonic acid-protonated polyaniline (Pani) with different amounts of multiwall carbon nanotube (MWCNT) was investigated in this paper. The MWCNT/Pani composite films were deposited by a spin-coating method on both ITO and Au-interdigitated electrodes (Au-IDE) substrates. Sensor film characteri...
Preprint
Full-text available
In this study, the electronic properties of pristine and Li-doped BN flakes have been studied by first-principle density functional theory and the B3LYP/6-31G(d,p) level. Accordingly, for pristine flakes, stability increases as the size increases. For doped flakes, the adsorption energy also increases as the size increases. And, for the $N-H$ bond...
Article
Full-text available
The purpose of the present study is to evaluate the effects of different laser irradiations including Nd-YAG (neodymium-doped yttrium aluminum garnet laser; Nd:Y3Al5O12), Er-YAG (erbium-doped yttrium aluminum garnet laser, erbium YAG laser), and Carbon dioxide (CO2) infrared lasers on surface topography of zirconia-based ceramics samples which were...
Article
Full-text available
Further to traditional corrosion monitoring techniques for rated deteriorations, nowadays modern electrochemical monitoring methods are promising for the control of non-rated damage mechanisms. Considering carbon steel as the most commonly used alloy in the oil and gas industry, there are special grades under NACE MR0175 standard which are immune t...
Article
Full-text available
Effects of diamond-like carbon (DLC) and Ag nanoparticles (Ag NPs) on photoanode of quantum dot sensitized solar cell (QDSSCs) have studied for the first time. Photoanodes include thin films of the TiO2 deposited on the FTO substrate, subsequently, graphene and CdS quantum dots (QDs) added on. Some photoanodes decorate by Ag nanoparticles and DLC t...
Article
Full-text available
The aim of the present study is to explore the 3-D micromorphology of human canine teeth materials using multifractal analysis through atomic force microscopy (AFM). The 3-D surfaces of ten extracted canine teeth of a group of 40 year old men were studied (enamel, inter enamel, inter dentin, and cementum) by AFM images in tapping mode and on square...
Article
Full-text available
In the present study, Ag nanoparticles were synthesized in amorphous hydrogenated carbon films on glass substrates by RF-PECVD and RF-sputtering co-deposition method at the room temperature. Methyl orange was utilized as an analyte with different concentrations on Ag nanoparticles that were embedded in diamond-like carbon (DLC). Ultraviolet–visible...
Article
Full-text available
Pure and co-doped Titania thin films were prepared on aluminum substrates through the sol-gel method. The co-doped sample showed higher photocatalytic activity on benzene degradation compared to pure TiO2 under visible light illumination. XRD results showed the anatase phase for both TiO2 and co-doped TiO2 lattices with an average crystalline size...
Article
Full-text available
The purpose of the present study was to investigate a new method to evaluate micro topography and micro morphology of hard tissue of canine teeth using an atomic force microscope (AFM). For this aim, three extracted human canine teeth were applied. The unpolished surfaces were analyzed with AFM images with 15 µm × 5 µm area and their information ob...
Article
Full-text available
In this study, a stereometric analysis of the three-dimensional (3-D) surfaces of the Ag/diamond-like carbon (DLC) nanocomposite films was done. The nanocomposite thin films were fabricated by Radio Frequency Plasma-Enhanced Chemical Vapour Deposition (RF-PECVD). The 3-D surface microtexture was studied by high-resolution Atomic Force Microscopy (A...
Article
Full-text available
Determining surface topography of different tissues of the molar tooth with novel analytical methods has opened new horizons in dental surface measurements which characterize tooth surface quality in dentistry. Studying surface topological measurements and comparing surface morphology of hard tissue of the molar tooth are the ultimate goals of the...
Preprint
In this paper, the results of helium plasma jet treatment of hard tissues of natural human teeth including enamel, dentin, and cementum are presented. Changes in surface morphology and structural properties have been investigated using scanning electron microscopy (SEM) in connection with multiscale image analysis, X-ray diffraction (XRD) with the...
Article
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We demonstrate the possibility to tune the distribution of deep localized states and electronic transport properties of TiO 2 nanotube arrays (TNA)through decoration its surface with Pt or [email protected] (Diamond-like carbon). A quantitative calculation of the position of the deep trap states in the band gap and the amount of accumulated charge...
Article
Full-text available
Phenotypic variation – such as disease susceptibility and differential drug response – has a strong genetic component. Substantial effort has therefore been made to identify causal genomic variants explaining such variation among humans. Point mutations (PMs), which are single nucleotide changes in the genome, have been identified to be the most ab...
Article
Full-text available
Objective: Substantial effort has been put into designing DNA-based biosensors, which are commonly used to detect presence of known sequences including the quantification of gene expression. Porous silicon (PSi), as a nanostructured base, has been commonly used in the fabrication of optimally transducing biosensors. Given that the function of any...
Article
Among the different synthesizingmethod of graphene, besides having amost suitable and cost-effective method, it is essential to have high-quality graphene. For this reason, the effects of the cathode electrode, the time and type of voltage variation, dispersion time, the electrolyte salt and washing solvent on process performance of electrochemical...
Article
Full-text available
Among the different synthesizing method of graphene, besides having a most suitable and cost-effective method, it is essential to have high-quality graphene. For this reason, the effects of the cathode electrode, the time and type of voltage variation, dispersion time, the electrolyte salt and washing solvent on process performance of electrochemic...
Article
Full-text available
It is well known that all biological systems which undergo oxidative metabolism or oxidative stress generate a small amount of light. Since the origin of excited states producing this light is generally accepted to come from chemical reactions, the term endogenous biological chemiluminescence is appropriate. Apart from biomedicine, this phenomenon...
Article
Full-text available
The objective of this study was to evaluate the effect of two photoactivation modes of dental LED light‐curing unit (LCUs) (conventional and “Soft Start” mode) on surface texture parameters of two dental resin‐based nanocomposites. LED LCUs were considered as standard light‐curing devices in contemporary dental practice. Atomic force microscopy (AF...
Article
Full-text available
Knowing the exact pressure of the process has a great impact on the validity of the results, product quality, energy efficiency, and in some processes, on the security of work with the system. Hence, the calibration of the barometers and the accuracy of the readings should be taken seriously. Choosing the appropriate time interval for re-calibratio...
Article
Full-text available
Nowadays, increasing awareness of environment and fossil fuels protection stimulates intensive research on clean and renewable sources of energy. Production of hydrogen from water through solar-driven splitting reactions is one of the most promising approaches in the field of photoelectrochemistry (PEC). In this work we have fabricated well-aligned...
Article
Full-text available
In this paper, due to the importance and abundant applications of carbon nanotubes doped with boron (CNT/B2O3) in various industries with changes in the electrical, mechanical and chemical properties, mode identification and intensity of the Raman spectra of pure and boron oxide molecule-doped spectra have been performed. The main task in this pape...
Article
Full-text available
It is a challenge to fabricate high-quality graphene sheets due to the different effects of external factors on the fabrication process. Ultrasonic waves and temperature can be used as two important external factors to fabricate graphene. We conducted a research to study the effects of ultrasonic waves and temperature on the graphene fabrication pr...
Article
Full-text available
Organisms undergoing oxidative metabolism or stress chemically generate electronically excited species through dioxetane and tetroxide pathways. Consequently, luminescence is emitted which could be exploited for non-invasive label-free monitoring of oxidative stress. Spectral analysis of this endogenous chemiluminescence can serve as a tool for ide...
Article
Full-text available
Iron nanoparticles in amorphous hydrogenated carbon films (FeNPs@a-C:H) were prepared with RF-sputtering and RFPECVD methods by acetylene gas and Fe target. In this paper, deposition and sputtering process were carried out under influence of different initial pressure gas. The morphology and roughness of surface of samples were studied by AFM techn...
Article
Full-text available
A new compound Mn0.9Co0.1Al2O4 nanowires were synthesized by thermal method. The resulting powder samples were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). We found that a set of phase transformation occurred during the process. Eventually, five phases including three...
Article
Full-text available
Silver-Gold alloy/diamond like carbon (Ag-Au/DLC) nanocomposite films were prepared by co-deposition of RF-sputtering and RF-PECVD on glass substrates by using acetylene gas and silver-gold target. The deposition process was carried out at room temperature in one minute with the variable parameters of initial pressures and RF powers. X-ray diffract...
Article
Full-text available
Atomic force microscopy (AFM) images give valuable information about surface roughness of thin films based on the results of power spectral density (PSD) through the fast Fourier transform (FFT) algorithms. In the present work, AFM data are studied for silver and gold nanoparticles (Ag NPs a-C: H and Au NPs a-C: H) embedded in amorphous hydrogenate...
Article
Full-text available
Organisms undergoing oxidative metabolism or stress chemically generate electronically excited species through dioxetane and tetroxide pathways. Consequently, luminescence is emitted which could be exploited for non-invasive label-free monitoring of oxidative stress. Spectral analysis of this endogenous chemiluminescence can serve as a tool for ide...
Article
Full-text available
Novel formulations of nanocomposites derived from ZnO nanoparticles have provided potential biomedical applications as a new strategy for treatment of breast cancer. In this research, two types of ZnO nanomaterials were synthesized by sol–gel hydrothermal process and co-precipitation containing fast quenching and also surface modification methods....
Article
Full-text available
Recently d-dimensional spherically symmetric charged Vaidya black hole solution has been constructed. We observe that this nonstationary solution admits extremal limit and study its near horizon geometry. We show that the symmetry of the near horizon geometry is SO(2, 1) × SO(d − 1). Our analysis shows that the theorems for the near horizon geometr...
Conference Paper
Full-text available
Ag nanoparticles were deposited on glass substrate by RF-PECVD and RF-sputtering co-deposition method. Methyl orange (MO) with different concentrations on Ag-DLC substrate has been utilized as an analyte. These concentrations reached to 10-9 (M) and it shows that Ag nanoparticles is an active substrate for SERS. Sensitivity of measurements in SERS...
Article
Full-text available
We investigate the effects of different contents of multiwall carbon nanotubes (MWCNTs) on optical and electrical properties of polyaniline (PANI). The MWCNTs/PANI composites are deposited on glass substrates coated with indium tin oxide (ITO) by the spin-coating technique. The scanning electron microscopy shows that nanotubes are coated with the P...
Article
Full-text available
The effect of gamma irradiation dose in the range of 1–10 kGy is investigated on the structural, optical and electrical properties of the polyaniline -emeraldine salt (PANI-ES) thin films deposited on the indium tin oxide (ITO) coated glass substrate by spin coating technique. X-ray diffraction patterns show that all deposited PANI films have an am...
Article
Full-text available
Silver–diamond like carbon (Ag–DLC) nanocomposite films were deposited on glass and silicon substrates by co-deposition of RF-sputtering and RF-PECVD method in acetylene plasma. The effects of deposition time on creation of conductive percolation pathway in Ag–DLC nanocomposite films were investigated. The films were characterized by XRD pattern, A...
Article
Full-text available
The presented study is aimed at analyzing the surface texture of amorphous hydrogenated carbon layers containing nickel nanoparticles (Ni-NPs@a-C:H) within their structure, which were deposited by Radio Frequency (RF) sputtering and RF-Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) methods on glass substrates. Prepared films were then used as...
Article
Full-text available
In the present work amorphous hydrogenated carbon films with sputtered iron nanoparticles (Fe NPs @ a-C:H) were deposited by co-deposition of RF-sputtering and RF-plasma enhanced chemical vapor deposition methods using acetylene gas and iron target on quartz and silicon substrates. Samples were prepared in different initial pressures and during con...
Article
Full-text available
A novel insight into the effect of Pt decoration on electrochemical and photoelectrochemical behavior of TiO2 nanotube arrays (TNA) was developed in this study. TNA samples were prepared via a two-step anodization of a titanium foil and decorated with Pt by a facile photodeposition method. The formation of metallic Pt were confirmed by X-ray photoe...
Article
In this paper the sputtered gold nanoparticles (NPs) deposited by Radio Frequency-Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) method on the glass substrates in trace of amorphous hydrogenated carbon (Au NPs @ a-C: H) were analyzed to study the three-dimensional (3-D) surface texture. The prepared Au NPs @ a-C: H films were used as research...
Article
Full-text available
This paper analyzes the three-dimensional (3D) surface texture of amorphous hydrogenated carbon films with sputtered iron nanoparticles (FeNPs@a-C:H) deposited by a radio-frequency plasma-enhanced chemical vapor deposition method on the quartz substrates. The prepared FeNPs@a-C:H films were used as research materials. The synthesized samples were d...
Article
Full-text available
Lead sulfide quantum dots (PbS QDs) were decorated onto a graphene surface in a semi-core–shell structure using supercritical ethanol. The temperature of ethanol played significant role in controlling size and agglomeration of QDs as well as the extent of reduction of graphene. Average size of the QDs was estimated by transmission electron microsco...
Article
Full-text available
Nickel nanoparticles arrays, growth into hydrogenated amorphous carbon, were prepared by means of RF-plasma enhanced chemical vapor deposition and RF-sputtering co-deposition from acetylene and a nickel target. The resulting nanocomposite films were characterized by X-ray diffraction and atomic force microscopy, and their magnetic responses and...
Article
Full-text available
Silver nanoparticles embedded in DLC matrix, were prepared by co-deposition of RF-Sputtering and RF-PECVD method from acetylene gas and sliver target. The RF power and initial pressure of chamber were fixed. Variations of morphology, optical and electrical properties of these films over time were investigated.
Article
Graphene clusters consisting of 24 to 150 carbon atoms and hydrogen termination at the zigzag boundary edges have been studied, as well as clusters disordered by vacancy(s). Density Function Theory and Gaussian03 software were used to calculate graphene relative stability, desorption energy, band gap, density of states, surface shape, dipole moment...