Optical properties of silicon nanocrystals in silica: Results from spectral filtering effect, m-line technique, and x-ray photoelectron spectroscopy

2008 ◽  
Vol 104 (10) ◽  
pp. 104316 ◽  
Author(s):  
Leonid Khriachtchev ◽  
Timur Nikitin ◽  
Claudio J. Oton ◽  
Rama Velagapudi ◽  
Jani Sainio ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Silicon Nanocrystals ◽  
Spectral Filtering ◽  
X Ray ◽  
Filtering Effect

scholarly journals Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 124
Author(s):  
Srihasam Saiganesh ◽  
Thyagarajan Krishnan ◽  
Golla Narasimha ◽  
Hesham S. Almoallim ◽  
Sulaiman Ali Alhari ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Rare Earth ◽  
Nickel Oxide ◽  
Photoelectron Spectroscopy ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nio Nanoparticles ◽  
X Ray ◽  
Sesbania Grandiflora

Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.

scholarly journals Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Crystal Size ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

Extraordinary Stability of Structural and Electronic Properties of Tin Oxide Nanoparticles Formed by Soft Chemistry

2010 ◽  
Vol 75 ◽  
pp. 36-42 ◽  
Author(s):  
Marina Rumyantseva ◽  
Irina Zhurbina ◽  
Elena Varechkina ◽  
Siranuysh Badalyan ◽  
Alexander Gaskov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Tin Dioxide ◽  
Hydrogen Reduction ◽  
Nitrogen Adsorption ◽  
Ammonia Solution ◽  
Adsorption Method ◽  
X Ray ◽  
Wet Chemical Synthesis ◽  
Tin Chloride

Powders of tin dioxide (SnO2) have been prepared by two different modifications of wet chemical synthesis, i.e. (i) by conventional hydrolysis of tin chloride dissolved in aqueous ammonia solution and (ii) by precipitation from tin chloride dissolved in aqueous hydrazine monohydrate (N2H4*H2O) solution. The prepared gels were dried and then annealed at different temperatures varied from 300 to 700 oC in order to form nanocrystals. Structure and optical properties of the samples were investigated by using X-ray diffraction, transmission electron microscopy, thermoprogrammable hydrogen reduction, low temperature nitrogen adsorption method, photoluminescence, infra-red absorption, Raman spectroscopy, and X-ray photoelectron spectroscopy. The samples prepared by hydrazine-based method are characterized by surface area about 127-188 m2/g with high sintering resistance. The optical spectroscopy data revealed pure crystallinity and high defect concentration for the samples prepared by hydrazine-based method. The experimental results are discussed in view of different states of chemisorbed oxygen on SnO2 nanocrystal surfaces, which determine electronic and optical properties of the prepared samples.

scholarly journals Studies of Effects of Calcination Temperature on the Crystallinity and Optical Properties of Ag-Doped ZnO Nanocomposites

2019 ◽  
Vol 3 (1) ◽  
pp. 18 ◽  
Author(s):  
Md. Molla ◽  
Mai Furukawa ◽  
Ikki Tateishi ◽  
Hideyuki Katsumata ◽  
Satoshi Kaneco
Keyword(s):  
Optical Properties ◽  
Calcination Temperature ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Band Edge ◽  
High Yield ◽  
Band Edge Emission ◽  
X Ray ◽  
Calcination Temperatures ◽  
Doped Zno

Ag-doped ZnO nanocomposites are successfully synthesized at different calcination temperatures and times through a simple, effective, high-yield and low-cost mechanochemical combustion technique. Effects of calcination temperature on the crystallinity and optical properties of Ag/ZnO nanocomposites have been studied by X-ray diffraction (XRD), UV−visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL) and X-ray photoelectron spectroscopy (XPS). The XRD patterns of the synthesized Ag/ZnO exhibit a well-crystalline wurtzite ZnO crystal structure. The grain size of Ag/ZnO nanocomposites is found to be 19 and 46 nm at calcination temperatures of 400 °C and 700 °C, respectively. The maximum absorption in the UV region is obtained for Ag/ZnO nanocomposites synthesized at a calcination temperature of 500 °C for 3 h. The peak position of blue emissions is almost the same for the nanocomposites obtained at 300–700 °C calcination temperatures. The usual band edge emission in the UV is not obtained at 330 nm excitation. Band edge and blue band emissions are observed for the use of low excitation energy at 335–345 nm.

Photovoltaic properties of silicon nanocrystals in silicon nitride prepared by ammonia sputtering

2015 ◽  
Vol 08 (05) ◽  
pp. 1550052
Author(s):  
Xiaobo Chen
Keyword(s):  
Silicon Nitride ◽  
Flow Rate ◽  
Photoelectron Spectroscopy ◽  
Silicon Nanocrystals ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Photovoltaic Properties ◽  
X Ray ◽  
Xps Characterization

In this work, we present an investigation of the photovoltaic properties of low-temperature (700°C annealing temperature) prepared P -doped Silicon nanocrystals ( Si   NCs ) in silicon nitride by ammonia sputtering followed by rapid thermal annealing (RTA). We examined how the flow rate of NH3influenced the structural properties of the annealed films by using Raman scattering, grazing incidence X-ray diffraction (GI XRD) and transmission electron microscopy (TEM), it was found that the appropriate flow rate of NH3is 3 sccm. For the sample deposited at the flow rate of 3 sccm, TEM image showed that Si   NCs were formed with a mean size about 3.7 nm and the density of ~ 2.1 × 1012cm-2; X-ray photoelectron spectroscopy (XPS) characterization showed the existence of Si – P bonds, indicating effective P doping; the average absorptance of higher than 65% and a significant amount of photocurrent makes it suitable for photoactive. Moreover, the experimental P -doped Si   NCs : Si3N4/ p - Si heterojunction solar cell has been fabricated, and the device performance was studied. The photovoltaic device fabricated exhibits an open-circuit voltage (VOC) and a short-circuit current density (JSC) of 470 mV and 3.25 mA/cm2, respectively.

Electronic structure and optical properties of Cs 2 HgCl 4 : DFT calculations and X-ray photoelectron spectroscopy measurements

2016 ◽  
Vol 60 ◽  
pp. 169-180 ◽  
Author(s):  
A.A. Lavrentyev ◽  
B.V. Gabrelian ◽  
V.T. Vu ◽  
O.V. Parasyuk ◽  
A.O. Fedorchuk ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Dft Calculations ◽  
Photoelectron Spectroscopy ◽  
X Ray

Multiferroic Bismuth Ferrite Nanoparticles: Rapid Sintering Synthesis, Characterization, and Optical Properties

2010 ◽  
Vol 152-153 ◽  
pp. 81-85
Author(s):  
Xiong Wang ◽  
Yin Lin ◽  
Jin Guo Jiang
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Bifeo3 Nanoparticles ◽  
Rapid Sintering

The homogeneous multiferroic BiFeO3 nanoparticles with average particle size of 85 nm have been successfully synthesized by a simple sol-gel route. The prepared sample was characterized by a variety of techniques, such as X-ray diffractometry, thermogravimetric analysis and differential thermal analysis, differential scanning calorimeter analysis, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The obtained results shows that rapid sintering and subsequently quenching to room temperature are the two vital important factors for the preparation of pure BiFeO3. The magnetic phase transition (TN = 369 °C) and the ferroelectric phase transition (TC = 824.5 °C) were determined, revealing the antiferromagnetic and ferroelectric nature of the as-prepared BiFeO3 nanoparticles. The optical properties of the nanopowders were investigated. The strong band-gap absorption at 486 nm (2.55 eV) of the BiFeO3 nanoparticles may bring some novel applications.

scholarly journals Porous Silicon-Zinc Oxide Nanocomposites Prepared by Atomic Layer Deposition for Biophotonic Applications

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1987 ◽  
Author(s):  
Mykola Pavlenko ◽  
Valerii Myndrul ◽  
Gloria Gottardi ◽  
Emerson Coy ◽  
Mariusz Jancelewicz ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Porous Silicon ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
Visible Range ◽  
Optical Biosensing ◽  
X Ray ◽  
Layer Deposition

In the current research, a porous silicon/zinc oxide (PSi/ZnO) nanocomposite produced by a combination of metal-assisted chemical etching (MACE) and atomic layer deposition (ALD) methods is presented. The applicability of the composite for biophotonics (optical biosensing) was investigated. To characterize the structural and optical properties of the produced PSi/ZnO nanocomposites, several studies were performed: scanning and transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance, and photoluminescence (PL). It was found that the ALD ZnO layer fully covers the PSi, and it possesses a polycrystalline wurtzite structure. The effect of the number of ALD cycles and the type of Si doping on the optical properties of nanocomposites was determined. PL measurements showed a “shoulder-shape” emission in the visible range. The mechanisms of the observed PL were discussed. It was demonstrated that the improved PL performance of the PSi/ZnO nanocomposites could be used for implementation in optical biosensor applications. Furthermore, the produced PSi/ZnO nanocomposite was tested for optical/PL biosensing towards mycotoxins (Aflatoxin B1) detection, confirming the applicability of the nanocomposites.

scholarly journals Surface Stoichiometry and Optical Properties of Cux–TiyCz Thin Films Deposited by Magnetron Sputtering

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 551 ◽  
Author(s):  
Avishek Roy ◽  
Arun Kumar Mukhopadhyay ◽  
Sadhan Chandra Das ◽  
Gourab Bhattacharjee ◽  
Abhijit Majumdar ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Metal Matrix ◽  
Optical Band Gap ◽  
Matrix Composites ◽  
X Ray ◽  
Peak Intensity ◽  
Ternary Carbide

Ternary carbide in metal matrix composites constitute a big challenge in the industry, and in this regard their surface treatment is one of the most important issues. Ternary carbide (CuxTiyCz, where x, y and z are integers) thin films are synthesized by magnetron sputtering and characterized with respect to the film depth. X-ray photoelectron spectroscopy (XPS) of Cu-2p and Ti-2p peaks shows the associated shake-up satellite peaks at a smaller film depth; the peak intensity is reduced at a higher depth. The relative intensity of Cu and Ti increases at a larger film depth. The optical band gap varies from 1.83 to 2.20 eV at different film depths.

Analysis of Optical Properties and Structure for CdS Films

2005 ◽  
Vol 475-479 ◽  
pp. 3721-3724
Author(s):  
W.L. Wang ◽  
K.J. Liao ◽  
Jian Zhang ◽  
P. Yu ◽  
G.B. Liu
Keyword(s):  
Optical Properties ◽  
Chemical Bath Deposition ◽  
Photoelectron Spectroscopy ◽  
Annealing Treatment ◽  
Oxide Content ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
Transparent Glass ◽  
X Ray ◽  
Cds Films

In this paper, the optical properties and structure of CdS films were investigated by SEM, X-ray diffraction, and x-ray photoelectron spectroscopy. The CdS films in this study were deposited on the plane transparent glass by chemical bath deposition technique. The experimental results have shown that the annealing treatment has an important effect on the optical properties and structure of CdS films. This may be ascribed to decreasing surface contaminations and oxide content in the films.

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