Bashir Ahmmad

Bashir Ahmmad
Yamagata University | YU · Department of Informatics and Electronics

PhD

About

79
Publications
38,554
Reads
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1,500
Citations
Additional affiliations
April 2017 - present
Yamagata University
Position
  • Professor
October 2012 - March 2017
Yamagata University
Position
  • Professor
April 2012 - September 2012
Kyushu University
Position
  • Researcher

Publications

Publications (79)
Article
Room-temperature atomic layer deposition (RT-ALD) of iron oxide is developed with a precursor of bis(N, N′-diisopropyl-propionamidinate)iron [(DIPPA) 2 Fe] and plasma excited humidified Ar. Saturated conditions of (DIPPA) 2 Fe and plasma excited humidified Ar exposures at room temperature (23–25 °C) are investigated by in situ IR absorption spectro...
Article
Full-text available
Organic molecule (Histidine) embedded cadmium sulfide (CdS) nanocomposites are prepared by the solvothermal method. CdS nanocomposite, prepared with 1:1 M ratio of S²⁻ to Cd²⁺, shows the highest crystallinity and highest hydrogen production via water splitting. Optimization of Pt deposition indicates that 5.5 wt% of Pt deposition on CdS nanocomposi...
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We report on the magnetic and optical properties of DyFe0.5Cr0.5O3 nanoparticles synthesized by sol-gel method. Rietveld refinement of powder X-ray diffraction (XRD) pattern confirms the formation of orthorhombic disordered phase with Pnma space group. The formation of nano-sized particles, with an average size of 42(±12) nm, was approximated by th...
Article
Nano crystalline zinc oxide (ZnO) is deposited by room temperature atomic layer deposition (RT-ALD) using dimethylzinc and a plasma excited humidified Ar without thermal treatments. The TEM observation indicated that the deposited ZnO films were crystallized with grain sizes of ∼20 nm on Si in the course of the RT-ALD process. The crystalline ZnO e...
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We report the effect of temperature on the crystallographic structure and magnetic properties of ultrasonically prepared nanostructured Nd0.7Sr0.3MnO3 perovskite manganite. The crystal structure of as-synthesized nanoparticles remains unaltered over a wide scanning temperature range. Temperature dependent magnetization measurements demonstrate that...
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Pure cadmium sulfide and histidine decorated cadmium sulfide nanocomposites are prepared by the hydrothermal or solvothermal method. Scanning electron microscopy (SEM) analysis shows that the particle sizes of pure cadmium sulfide (pu/CdS) and histidine decorated cadmium sulfide prepared by the hydrothermal method (hi/CdS) range from 0.75 to 3.0 μm...
Article
To improve the efficiency of organic photovoltaics (OPVs), the trapping of incident light with surface nanostructures, such as moth eye structures, is a highly useful strategy for enhancing absorption in the photoactive layer. Nanoimprint lithography is a widely used technique to produce large-area nanostructures cost effectively. However, the moth...
Article
To improve the performance of organic photovoltaics, we investigate an integrated device design in which the hybrid antireflection structure, composed of a surface moth-eye nanotexture and a multilayer interference film, is applied with a high-refractive-index glass substrate. The moth eye texture with a relatively long period, which is near the ba...
Article
Room temperature (RT) atomic layer deposition (ALD) of Nb2O5 is developed using (tert-butylimido)tris(ethylmethylamido)niobium and a plasma excited humidified Ar. To design the process condition, an in situ monitoring system of IR absorption spectroscopy (IRAS) is utilized to observe the surface saturation of precursors. Based on the saturation cha...
Article
In Bangladesh, India, and Pakistan the ship breaking (SB) sector dismantles end-of-life ships on open beaches, exposing the environment to the resulting pollution, especially the soil and water. Because SB occurs in the vicinity of other poorly-regulated activities in industrial zones (IZ) in these countries, there is some ambiguity concerning the...
Article
We report room-temperature atomic layer deposition (ALD) of SnO2 using tetramethyltin (TMT) as a precursor and plasmaexcited humidified argon as an oxidizing gas and investigate the saturation behaviors of these gases on SnO2-covered Si prisms by IR absorption spectroscopy to determine optimal precursor/oxidizer injection conditions. TMT is demonst...
Article
The authors present a plasma enhanced room-temperature atomic layer deposition (ALD) technique for depositing aluminum silicate on TiO2 photoanodes for dye-sensitized solar cells. In the ALD process, adsorption of the precursor is completed in a two-step process involving sequential application of a subsaturation quantity of tris(dimethylamino)sila...
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A simple route to prepare Gd0:7Sr0:3MnO3 nanoparticles by ultrasonication of their bulk powder materials is presented in this article. For comparison, Gd0:7Sr0:3MnO3 nanoparticles are also prepared by ball milling. The prepared samples are characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersi...
Article
We propose a new antireflection (AR) design for organic photovoltaics (OPVs) to achieve broadband and omnidirectional enhancement of photocurrent. In the proposed design, a hybrid AR structure, which combines moth eye texturing and two-layer interference coating, is integrated with a glass substrate having a high refractive index (n). Using the opt...
Article
The synthesis as well as structural, multiferroic and optical characterization of Dy doped BiFeO3 multiferroic ceramic are presented. Bulk polycrystalline Bi0.9Dy0.1FeO3 sample is synthesized by solid state reaction, while their nano counterparts are prepared using ultrasonic probe sonication technique. Significant improvement of phase purity in th...
Article
The authors developed a room temperature atomic layer deposition (ALD) system that can deposit TiO2 on gold nanoparticles by using tetrakis(dimethylamino)titanium and plasma-excited humidified argon. The growth per cycle of TiO2 was measured to be 0.25 nm/cycle on a monitored Si sample. For applying the nanoparticle coating, the source material, i....
Article
Sr-substituted perovskites, La1.8Sr0.2MMnO6 (M = Ni, Co), were synthesized using the solid-state reaction technique to present a systematic study on their morphological, structural and magnetic properties. The average grain size of the as-prepared La1.8Sr0.2NiMnO6 samples are in the range of 0.2–0.7 µm and those for La1.8Sr0.2CoMnO6 manganites are...
Article
In this investigation, undoped BiFeO3, Gd doped Bi0.9Gd0.1FeO3, and Gd-Ti co-doped Bi0.9Gd0.1Fe1−xTixO3 (x = 0.10, 0.20) materials were synthesized to report their multiferroic properties. The structural analysis and phase identification of these multiferroic ceramics were performed using Rietveld refinement. The Rietveld analysis has confirmed the...
Article
Full-text available
To improve the performance of organic photovoltaics (OPVs), it is useful to trap light by using the antireflection nanotexture such as moth eye structure. The finite-difference time-domain (FDTD) method is frequently used to analyze the optical properties of nanotexture. However, in the case that FDTD is applied to OPVs, the existence of a glass su...
Article
Room-temperature atomic layer deposition (ALD) of ZrO2 is developed with tetrakis(ethylmethylamino)zirconium (TEMAZ) and a plasma-excited humidified argon. A growth per cycle of 0.17 nm/cycle at room temperature is confirmed, and the TEMAZ adsorption and its oxidization on ZrO2 are characterized by IR absorption spectroscopy with a multiple interna...
Article
The ceramic pellets of the nominal compositions Bi0.7Ba0.3Fe1−xTixO3 (x = 0.00-0.20) were prepared initially by standard solid state reaction technique. The pellets were then ground into micrometer-sized powders and mixed with isopropanol in an ultrasonic bath to prepare nanoparticles. The X-ray diffraction patterns demonstrate the presence of a si...
Article
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Improvement in magnetic and electrical properties of multiferroic BiFeO3 in conjunction with their dependence on particle size is crucial due to its potential applications in multifunctional miniaturized devices. In this investigation, we report a study on particle size dependent structural, magnetic and electrical properties of sol-gel derived Bi0...
Article
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We have investigated the effect of temperature on magnetic properties of Bi$_{0.9}$Gd$_{0.1}$Fe$_{1-x}$Ti$_x$O$_3$ (x = 0.00-0.20) multiferroic system. Unexpectedly, the coercive fields ($H_{c}$) of this multiferroic system increased with increasing temperature. The coercive fields and remanent magnetization were higher over a wide range of tempera...
Article
To improve the power conversion efficacy of organic photovoltaics (OPVs), it is required to design antireflection structures that could realize efficient and broadband light trapping. In this article, we perform global optimization of the textured pattern of moth eye antireflection surfaces to maximize the short-circuit current density (J SC) of OP...
Article
Full-text available
Fundamental surface reactions in the atomic layer deposition of GaN with trimethylgallium (TMG) and plasma-excited NH3 are investigated by multiple-internal-reflection infrared absorption spectroscopy (MIR-IRAS) at surface temperatures varying from room temperature (RT) to 400°C. It is found that TMG is saturated at RT on GaN surfaces when the TMG...
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This article discusses the hydrothermal synthesis of well-dispersed faceted α-GaOOH in the presence of sodium acetate by the self-assembly method. The synthesized α-GaOOH possesses a mixture of hexagonal and rectangular plates, cubic and diamond-like morphologies. The presence of ethanol as a co-solvent with water (1:1) facilitates scroll-like cyli...
Article
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The exchange bias (EB) effect has been observed in magnetic Bi0.9Gd0.1Fe0.9Ti0.1O3 nanoparticles. The influence of magnetic field cooling on the exchange bias effect has also been investigated. The magnitude of the exchange bias field (HEB) increases with the cooling magnetic field, showing that the strength of the exchange bias effect is tunable b...
Article
Full-text available
Gallium oxide is expected as a channel material for thin film transistors. In the conventional technologies, gallium oxide has been tried to be fabricated by atomic layer deposition (ALD) at high temperatures from 100-450 °C, although the room-temperature (RT) growth has not been developed. In this work, we developed the RT ALD of gallium oxide by...
Article
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Nitrogen adsorption on thermally cleaned Si (100) surfaces by pure and plasma excited NH3 is investigated by in situ IR absorption spectroscopy and ex-situ X-ray photoelectron spectroscopy with various temperatures from RT (25°C) to 800°C and with a treatment time of 5 min. The nitrogen coverage after the treatment varies according to the treatment...
Article
Dielectric and magnetic properties of BiFeO3 samples, co-doped with Gd or Ba and Ti in place of Bi and Fe, respectively, were investigated. The bulk powder samples of nominal compositions of Bi0.9Gd0.1Fe1–xTixO3 and Bi0.7Ba0.3Fe1-xTixO3 (x=0.00-0.25) ceramics were synthesized by conventional solid state reaction technique. The as prepared ceramics...
Article
We propose a hybrid antireflection structure (ARS), which integrates moth eye texturing and multilayer interference coating, to improve efficiency of organic photovoltaic (OPV) solar cells. We perform nearly global optimization of the geometric parameters characterizing the hybrid ARS, by using optical simulations based on the finite-difference tim...
Article
Room-temperature atomic layer deposition (ALD) of HfO2 was examined using tetrakis (ethylmethylamino)hafnium (TEMAH) and remote plasma-excited water and oxygen. A growth rate of 0.26 nm/cycle at room temperature was achieved, and the TEMAH adsorption and its oxidization on HfO2 were investigated by multiple internal reflection infrared absorption s...
Article
The mesoporous α-GaOOH was synthesized using oxalic acid in a hydrothermal process at various hydrothermal temperatures and times. The nitrogen adsorption analysis indicated that α-GaOOH with surface areas ranging from 6 to 87 m2/g and pore sizes from 3.8 to 7.2 nm can be prepared by adjusting the experimental conditions. The photocatalytic hexaval...
Article
Full-text available
The effect of carbon materials on TiO 2 for the photocatalytic hydrogen gas production from water / alcohol mixtures was investigated. Single walled carbon nanotubes (SWNTs), multi walled carbon nanotubes (MWNTs), carbon nanofiber (CNF), fullerene (FLN), graphite (GP), and graphite silica (GS) were used as co-catalysts by directly mixing with TiO 2...
Article
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Bioplastic based on starch as the matrix and cellulose nanocrystals from rice straw as reinforcing filler were prepared in this study. The isolation of cellulose nanocrystal (CNC) followed a series of steps: delignification, sulfuric acid hydrolysis, and sonication. The process afforded short, rod-like CNCs with particle diameter ranging from 10 to...
Article
Full-text available
A green synthesis method of α-Fe 2 O 3 microparticles has been developed using the extract of green tea (camellia sinensis) leaves. The as-prepared microparticles were characterized by SEM, TEM, XRD, XPS, UV-visible spectroscopy, and N 2 adsorption analysis. The crystallized microparticles were elliptical in shape with a diameter and length of 1µm...
Article
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We present a simple technique to synthesize ultrafine nanoparticles directly from bulk multiferroic perovskite powder. The starting materials, which were ceramic pellets of the nominal compositions of Bi0.9Gd0.1Fe1-xTixO3 (x = 0.00-0.20), were prepared initially by a solid state reaction technique, then ground into micrometer-sized powders and mixe...
Article
Full-text available
Room-temperature atomic layer deposition (ALD) of TiO2 was developed using tetrakis(dimethylamino)titanium (TDMAT) and a remote-plasma-excited water vapor. A growth rate of 0.157 nm/cycle at room temperature was achieved, and the TDMAT adsorption and its oxidation on TiO2 were investigated by multiple-internal-reflection infrared absorption spectro...
Article
Nanoparticles of copper(I) oxide (cuprous oxide; Cu2O) were able to be synthesized from nano-restricted copper acetate (Cu(OAc)2) in micropores of single-wall carbon nanotubes (SWNTs) by visible-light photoreduction. The specific structure of confined Cu(OAc)2 in the micropore is indispensable for the reduction process to Cu2O by the irradiation, b...
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This article reports on recent developments in heterogeneous AOP processes such as photocatalysis, Fenton-like process and catalytic ozonation. The principle, mechanism, and influence of experimental conditions on the degradation of pollutants in heterogeneous catalytic ozonation and the photocatalytic process were discussed. Introducing solid cata...
Article
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Room temperature dielectric and magnetic properties of BiFeO3 samples, co-doped with magnetic Gd and non-magnetic Ti in place of Bi and Fe, respectively, were reported. The nominal compositions of Bi0.9Gd0.1Fe1–xTixO3 (x = 0.00-0.25) ceramics were synthesized by conventional solid state reaction technique. X-ray diffraction patterns revealed that t...
Article
Full-text available
Metal-organic chemical vapor deposition (MOCVD) method has been applied to grow nanostructured ZnO films on Si (100) substrate at temperatures ranging from 200 to 550 °C. The as-prepared films were characterized by XRD, SEM, XPS analysis. The growth rate of ZnO films increases with increasing the deposition temperatures. The deposition temperatures...
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A three-phase solid-state solar cell (SSSC) has been developed successfully using TaON nanoparticles or BiOI microspheres as a sensitizer material over a TiO 2 film and CuI as a hole collector. Stable current (I sc)–voltage (V oc) curves are found under ultraviolet (UV)– visible light irradiation with an efficiency of 0.15% and 0.10% for TaON-and B...
Article
Natural dolomite was calcined at different temperatures in the range 873–1373 K and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and N2 adsorption/desorption isotherm. The calcination temperature had considerable effect on the surface chemical composition, crystallinity, and basicity of CO2 gas...
Article
The study was conducted to reinforce starch-based biocomposite films using cellulose nanocrystals (CNCs) from garlic stalks. An average yield of 4.6% by mass based from air-dried garlic stalks was obtained through alkali delignification, acid hydrolysis and sonication. The isolated CNCs are spherical and have an average diameter of 35 nm and crysta...
Article
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The structure of hydrated Co ions confined in the nanospace of single-walled carbon nanotubes (SWNTs) has been studied using the X-ray absorption fine structure (XAFS) technique. Water adsorption isotherms on Co-impregnated SWNTs indicate a high affinity of Co ions to water molecules. The results of XAFS analysis provided the information on the pro...
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This article reports a novel fabrication method for In(OH)3 from indium oxalate by hydrothermal process. Hydrothermal decomposition of indium oxalate at 180 degrees C for 10 h results in In(OH)3. The influence of hydrothermal experimental conditions such as temperature, time on the formation of indium hydroxide was investigated. The self-assembly p...
Article
We shed light on the specific hydration structure around a zinc ion of nanosolution restricted in a cylindrical micropore of single-wall carbon nanotube (SWNT) by comparison with the structure restricted in a cylindrical mesopore of multi-wall carbon nanotube (MWNT) and that of bulk aqueous solution. The average micropore width of open-pore SWNT wa...
Article
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A green synthesis method for the preparation of mesoporous α-Fe2O3 nanoparticles has been developed using the extract of green tea (camellia sinensis) leaves. This simple and one-step method can suitably be scaled up for large-scale synthesis. The as-prepared mesoporous nanoparticles were characterized by SEM, TEM, XRD, XPS, Raman, UV–visible spect...
Article
ABSTRACT: In this article, we report the fabrication of gallium oxide (α-Ga2O3) microspheres (GOMs) by a self-assembly process. Gallium nitrate with oxalic acid in a hydrothermal process results in α-GaOOH, which was further converted into gallium oxide by calcinations at 450 �C for 3 h. We first report the formation of various morphological α-GaOO...
Article
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In this article, we have reported the fabrication of various morphological porous Co3O4 by thermal decomposition of cobalt oxalate at open atmospheric conditions. Uniform cobalt oxalate microrods and microneedles were synthesized without using any surfactants or templates in large scale. The cobalt oxalate preparation method was played a crucial ro...
Article
In this article, we report the fabrication of highly stable amorphous mesoporous iron oxides (AMIOs) with surface tunable properties by a template-free method. AMIOs with surface areas from 264 to 43 m2/g and mesopore sizes from 5 to 11 nm were synthesized. The synthesized AMIOs were characterized using X-ray diffraction (XRD), field emission scann...
Article
In this article, we have successfully fabricated various morphological beta-Indium sulfide (In2S3) superstructures by using indium thiocyanate complex at acidic pH. All the synthesis has been performed by a template-free, hydrothermal method at 195 degrees C for 3 h. The photocatalytic activity of synthesized In2S3 have been investigated by using U...
Article
We report herein an unprecedented one-step green synthesis of gold nanoparticles (G-AuNps), using naturally occurring Korean red ginseng root (Panax ginseng C.A. Meyer) without any special reducing/capping agents. The AuNps generated through this ginseng-mediated process did not aggregate suggesting that the phytochemicals present in them serve as...
Article
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A simple and fast synthesis method of gold and silver nanoparticles without any surfactant or reducing agent has been developed by using the extract of green tea (camellia sinensis) under microwave irradiation. The synthesized gold and silver colloidal nanoparticles were spherical in shape and have an average diameter of 13 and 17 nm for Au and Ag...
Article
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The metallic Cu nanoparticles have been successfully deposited on the heterogeneous TiO2 surface by the borohydride reduction of copper nitrate in water/CH3CN mixture under Ar atmosphere. The catalytic activity of the Cu–TiO2 nanocomposite was evaluated by the application to a photocatalytic cancer cell-killing under UV–visible light irradiation. B...
Article
Without using an external precursor a simple and one-step method for the synthesis of C-doped TiO2 submicrospheres has been developed via hydrolysis of titanium tetraisopropoxide in pure methanol followed by calcination under air at 500°C. Also, with the addition of d-glucose and NH4OH solution during the hydrolysis process, C- or N-doped and C, N...
Article
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The relation among the change of the crystal structure, the amount of doped N and the photocatalytic activity for the decomposition of methylene blue was studied. The N-doping was promoted by the change of the crystal structure from the rutile phase to the anatase phase. The photocatalytic activity for the decomposition of methylene blue was enhanc...