scholarly journals High-responsivity hybrid α-Ag2S/Si photodetector prepared by pulsed laser ablation in liquid

2020 ◽  
Vol 11 ◽  
pp. 1596-1607
Author(s):  
Raid A Ismail ◽  
Hanan A Rawdhan ◽  
Duha S Ahmed
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Laser Ablation ◽  
Energy Gap ◽  
Longitudinal Optical Phonon ◽  
Ambient Conditions ◽  
Optical Energy Gap ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Scanning Electron

We report the synthesis of α-Ag2S nanoparticles (NPs) by one-step laser ablation of a silver target in aqueous solution of thiourea (Tu, CH4N2S) mixed with cationic cetyltrimethylammonium bromide (CTAB) as surfactant. The effect of the CTAB surfactant on the structural, morphological, optical, and elemental composition of Ag2S NPs was evaluated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV–vis spectroscopy. The optical absorption decreased and the optical energy gap of α-Ag2S increased from 1.5 to 2 eV after the CTAB surfactant was added to the Tu solution. XRD studies revealed that the synthesized Ag2S NPs were polycrystalline with a monoclinic structure and that crystallinity of the nanoparticles was improved after adding CTAB. Raman studies revealed the presence of peaks related to Ag–S bonds (Ag modes) and the longitudinal optical phonon 2LO mode. Scanning electron microscopy investigations confirmed the production of monodisperse Ag2S NPs when using the CTAB surfactant. The optoelectronic properties of α-Ag2S/p-Si photodetector, such as current–voltage characteristics and responsivity in the dark and under illumination, were also improved after using the CTAB surfactant. The responsivity of the photodetector increases from 0.64 to 1.85 A/W at 510 nm after adding CTAB. The energy band diagram of the α-Ag2S/p-Si photodetector under illumination was constructed. The fabricated photodetectors exhibited reasonable stability after three weeks of storage under ambient conditions with a responsivity of 70% of the initial value.

The adsorption of methylene blue on montmorillonite from acid solutions

Clay Minerals ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Z. Klika ◽  
P. Pustková ◽  
M. Dudová ◽  
P. Čapková ◽  
Ch. Kliková ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Methylene Blue ◽  
Ion Exchange ◽  
Powder Diffraction ◽  
Acid Solutions ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Adsorption Wave ◽  
Scanning Electron

AbstractThe adsorption of methylene blue (MB) on montmorillonite from acid solutions has not yet been studied in detail. In this paper the adsorption of this dye on Ca/SAz montmorillonite from 0.32, 0.80 and 1.60 M HCl solutions at ambient temperature and after 2 hours leaching was carefully studied and evaluated. Under the above conditions the MB/SAz intercalates formed are practically insoluble. In contrast to the adsorption of methylene blue on montmorillonite from aqueous solutions, the adsorption from acid solutions consists of two adsorption waves. The intercalated samples from the first and second waves were studied using X-ray powder diffraction (XRD), FTIR, Vis spectroscopy, and scanning electron microscopy (SEM) equipped with a microprobe system. The adsorption of MB in the first wave is attributed to ion exchange of the dye cationic species (MB+, MB22+, H-aggregates, MBH2+ and H+) for the original interlayer cations of montmorillonite. The percentages of MBH2+ and H+ based on total adsorbed MB were estimated for varying HCl concentrations. The second adsorption wave is linked to the precipitation of MB species on the outer MB/SAz surface.

Fabrication of La Doped ZnO Nanorods via a Solvothermal Route

2009 ◽  
Vol 620-622 ◽  
pp. 529-532
Author(s):  
Tie Kun Jia ◽  
Wei Min Wang ◽  
Zheng Yi Fu ◽  
Fei Huang ◽  
Hao Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Zno Nanorods ◽  
Photocatalytic Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
La Doped ◽  
Scanning Electron

La doped ZnO nanorods were synthesized via solvothermal technique using Zn(AC)2 and La(NO3)3 as starting materials. The products were characterized by X-ray diffraction (XRD), field scanning electron microscopy (FESEM) equipped with an energy dispersion X–ray (EDX) spectrometer, photoluminescence spectroscopy and UV-vis spectroscopy. The results of XRD in combination with EDS indicated that La was successful doped in ZnO. The obtained La doped ZnO sample exhibited nanorod like morphology and the diameter was about 30 nm. The photocatalytic property of La doped ZnO was evaluated by the variation of the concentration of RhB.

The Synthesis of Graphene Oxide via Electrochemical Exfoliation Method

2015 ◽  
Vol 1109 ◽  
pp. 55-59 ◽  
Author(s):  
Nurhafizah Md Disa ◽  
Suriani Abu Bakar ◽  
S. Alfarisa ◽  
Azmi Mohamed ◽  
Illyas Md Isa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Scanning Electron Microscopy ◽  
Graphene Oxide ◽  
Sodium Dodecyl ◽  
Electrochemical Exfoliation ◽  
Spectra Analysis ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Scanning Electron

In this study, electrochemical exfoliation method was adopted in the production of graphene oxide (GO). The electrolyte used was sodium dodecyl sulphate (SDS) aqueous solution at various concentrations from 0.001 to 1.0 M. The effect of SDS concentrations on the morphology of GO samples were characterized using field emission scanning electron microscopy (FESEM), energy dispersive X-ray, micro-Raman and UV-Vis spectroscopy. As evident by the FESEM analysis, the concentration of SDS does give effect to the GO obtained in this study. The lowest GO production is given by the lowest concentration of SDS used which is 0.001 M. However, in term of ID/IGratio, the sample prepared at 0.001 M has the lowest value (0.33) as compared to the sample prepared with highest SDS concentration of 1.0 M (ID/IG~1.12). Meanwhile, the presence of absorbance peaks in the range of 224-237 nm from UV-Vis spectra analysis were seen for the whole samples and this indicate the formation of GO.

scholarly journals Magnetic Field – Assisted Laser Ablation of Titanium Dioxide Nanoparticles in Water for Anti-Bacterial Applications

2021 ◽  
Author(s):  
Hasan H. Bahjat ◽  
R.A. Ismail ◽  
Ghassan M. Sulaiman ◽  
Majid S. Jabir
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Laser Ablation ◽  
Titanium Oxide ◽  
Oxide Nanoparticles ◽  
Titanium Oxide Nanoparticles ◽  
X Ray ◽  
Vis Spectroscopy ◽  
The Magnetic Field ◽  
Scanning Electron

Abstract Titanium oxide nanoparticles (TiO2) were produced by pulsed Nd:YAG laser ablation in water under the effect of an external magnetic field. Various techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy Dispersive x-ray (EDX), transmission electron microscopy (TEM), UV-Vis spectroscopy, and Raman spectroscopy were used to characterize the TiO2 nanoparticles. The XRD analysis of titanium oxide nanoparticles revealed that the synthesized nanoparticles were polycrystalline with mixed of tetragonal anatase and rutile TiO2. Scanning electron microscope shows the formation of spherical nanoparticles and the particles agglomeration decreases and the particle size from increases from 25nm to 35nm when the magnetic field applied. The optical energy gap of TiO2 nanoparticles decreased from 4.6eV to 3.4eV after using the magnetic field during the ablation. Raman studies show the existence of five vibration modes belong to TiO2. The antibacterial effect assay revealed a largest inhibition zone in S. aureus and E. coli, with a more potent effect for TiO2 NPs prepared by magnetic field when compared with that prepared without presence of magnetic field.

Indium Nitride Nanoparticles Prepared by Laser Ablation in Liquid

2019 ◽  
Vol 18 (02) ◽  
pp. 1850021 ◽  
Author(s):  
Khawla S. Khashan ◽  
Sarah F. Abbas
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Laser Ablation ◽  
Indium Nitride ◽  
Fourier Transform Infrared ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Indium nitride InN nanoparticles NPs suspension prepared by Nd:YAG laser ablation of indium target submerged under ammonium hydroxide. The Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, UV/VIS/NIR spectrophotometer and Conductivity meter were used to determine the properties of the nanoparticles prepared with different laser conditions. Fourier transform infrared spectra exhibit the presence of In[Formula: see text]N and In–N bonds, which indicates the formation of InN particles. X-ray diffraction pattern observed in the formation of InN NPs with cubic phase, the average diameters of the dominant peak c-InN (101) were approximately 2[Formula: see text]nm. Scanning electron microscopy image shows the presence of a large number of spherical shape nanoparticles having a particle size in the range 2–40[Formula: see text]nm with a few individual nanoparticles larger than 128[Formula: see text]nm. The transmission spectra of InN NPs suspension have the maximum optical transmission edge at 1378[Formula: see text]nm with bandgap energy was 0.85–1.2[Formula: see text]eV. InN has high electrical conductivity that depends on temperature value with small activation energy at room temperature ranging from 0.0318[Formula: see text]meV to 0.1591[Formula: see text]meV.

Chlorhexidine Adsorption in Hydroxyapatite and Alginate Microspheres by Extrusion in Zinc and Calcium Chloride

2016 ◽  
Vol 720 ◽  
pp. 25-30 ◽  
Author(s):  
Nadia Mohammed Elmassalami Ayad ◽  
Daniel Navarro da Rocha ◽  
Andrea Machado Costa ◽  
Marcelo Henrique Prado da Silva
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Chloride ◽  
Crystalline Phase ◽  
X Ray ◽  
Zn Concentration ◽  
Vis Spectroscopy ◽  
Before And After ◽  
Xrd Patterns ◽  
Scanning Electron

In this work, the adsorption of a low-concentration solution of chlorhexidine (CHX), an antimicrobial drug, in hydroxyapatite (HA) and alginate microspheres was studied. The microspheres were formed by extrusion of a 1:10 mixture of alginate and HA in two different divalent solutions: CaCl2 and ZnCl2. UV-Vis spectroscopy showed that the microspheres adsorbed approximately half of the chlorhexidine in solution, which was initially at 0.2%. XRD patterns obtained prior adsorption confirmed the presence of HA as the only crystalline phase. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) analysis were performed before and after CHX adsorption. The spheres produced in CaCl2 solution did not show significant change after adsorption. However, samples obtained in ZnCl2 solution showed a different microstructure, with the presence of crystals with a high Zn concentration. X-Ray Fluorescence (XRF) confirmed the presence of ZnO in the samples after CHX absorption.

scholarly journals PREPARATION AND STUDY OF THE OPTICAL AND STRUCTURAL PROPERTIES NANOMEMBRANE

2021 ◽  
Vol 03 (03) ◽  
pp. 87-91
Author(s):  
Kamal H LATEEF ◽  
Haleemah J. MOHAMMED ◽  
Abothur G. MOHAMMED
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Structural Properties ◽  
Modern Technology ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Vis Spectroscopy ◽  
Scanning Electron

The adoption of nanotechnology to work within a field of sustainable energy within the preparation and manufacture of nano membrane ( CO3O4, TiO ) for fuel cell, which has prepared chemically. addition, using modern technology spraying ultrasound, to improve the structural, studied nano membrane have annealed in a vacuum and different temperature. studied optical properties membrane using UV- VIS spectroscopy, results of structural properties X-ray diffraction (XRD) showed that nanoparticles have polycrystalline also grain size decreased, composite nano membrane , Morphological studies using Scanning electron microscopy (SEM).

scholarly journals Enhancement of Photoconductive Detector Based on Carbon Nanotubes Decorated with Silver Nanoparticles by Adding Conductive Polymer

2021 ◽  
Vol 19 (50) ◽  
pp. 84-93
Author(s):  
Taqwa Yousif ◽  
Asama Naje
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Forward Bias ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Scanning Electron

In this work, wide band range photo detector operating in UV, Visible and IR was fabricated using carbon nanotubes (MWCNTs, SWCNTs) decorated with silver nanoparticles (Ag NPs). Silicon was used as a substrate to deposited CNTs/Ag NPs by the drop casting technique. Polyamide nylon polymer was used to coat CNTs/Ag NPs to enhance the photo-response of the detector. The electro-exploding wire technology was used to synthesize Ag NPs. Good dispersion of silver NPs achieved by a simple chemistry process on the surface of CNTs. The optical, structure and electrical characteristic of CNTs decorated with Ag NPs were characterized by X-Ray diffraction and Field Emission Scanning Electron Microscopy.  X-ray diffraction patterns of Ag NPs exhibited 2θ values (38.1°,44.3°) corresponding to the Ag nanocrystal, while the XRD pattern of MWCNTs and SWCNTs /Ag NPs peaks appeared at 2θ = 26.2° corresponding to the (002) and at 2theta=44° which corresponds with miller indices (100) for CNTs and (200) for Ag NPs. The optical properties measured by UV-Vis. Spectroscopy. Broad and strong surface plasmon resonance (SPR) peak was detected at 420 nm, for Ag NPs. The absorption of CNTs/Ag NPs increased significantly from UV to near IR region (300-1000 nm).  Ag NPs decorated CNTs without any impurities, according to field mission scanning electron microscopy examination, with typical particle sizes of (50-80nm) for Ag-NPs, 44nm for MWCNTs/Ag-NPs, and 30nm for SWCNTs/Ag NPs. ֹThe I-V characteristics at forward bias voltage (0.5-10) volt were studied. The figure of merits (responsivity, photocurrent gain, NEP and detectivity) after coating with polymer of the detector were measured in the dark and after illumination with UV LED (365 nm), Tungsten lamp (500-800 nm) and Laser diode (808 nm).

Sign in / Sign up

Export Citation Format

Share Document