Germanium Quantum Dot Sensitized TiO2 Solar Cells

2010 ◽  
Vol 442 ◽  
pp. 404-414 ◽  
Author(s):  
M. Abbas ◽  
B. Ali ◽  
S.I. Shah ◽  
P. Akhter
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Photoelectron Spectroscopy ◽  
Average Particle Size ◽  
Cell Performance ◽  
Average Particle ◽  
Solar Cell Performance ◽  
X Ray ◽  
Ge Quantum Dots

The size of Germanium (Ge) Quantum Dots (GQD’s) in Titanium Dioxide (TiO2) can be tailored, using different techniques like sputtering, laser ablation and sol gel. Similarly the absorption range of Ge may also be broadened in visible and NIR range. We report the use of Ge QD’s to sensitize meso-porous TiO2 film to make quantum dot sensitized solar cells (QDSSC) for the next generation photovoltaics. Ge -TiO2 nano-porous thin films were deposited using rf- planer magnetron sputtering using various ranges of rf-power, Argon pressure and substrate temperature. The fabricated films with various Ge concentrations were studied using X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), High Angle Annular Dark Field Imaging (HAADF) and UV-Visible Spectroscopy (UV-VIS).In the thin film meso-structure the Ge dots were embedded in the TiO2 matrix. The average particle size of Ge quantum dots was determined by HAADF. The solar cell performance has been checked using sun simulator. Experimental ways to improve cell performance are discussed.

scholarly journals Enhancement of organic solar cell performance by incorporating gold quantum dots (AuQDs) on a plasmonic grating

2020 ◽  
Vol 2 (7) ◽  
pp. 2950-2957 ◽  
Author(s):  
Sopit Phetsang ◽  
Supeera Nootchanat ◽  
Chutiparn Lertvachirapaiboon ◽  
Ryousuke Ishikawa ◽  
Kazunari Shinbo ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Solar Cell ◽  
Quantum Dot ◽  
Organic Solar Cells ◽  
Organic Solar Cell ◽  
Cell Performance ◽  
Solar Cell Performance ◽  
System P ◽  
Plasmonic Grating

The performance of organic solar cells was improved by the effect of a synergistic gold quantum dot/plasmonic grating system.

scholarly journals The effect of ZnO/ZnSe core/shell nanorod arrays photoelectrodes on PbS quantum dot sensitized solar cell performance

2020 ◽  
Vol 2 (1) ◽  
pp. 286-295 ◽  
Author(s):  
M. Kamruzzaman
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Quantum Dot ◽  
Cell Performance ◽  
Core Shell ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Solar Cell Performance ◽  
Sensitized Solar Cells ◽  
Pbs Quantum Dot

ZnO nanorod (NR) based inorganic quantum dot sensitized solar cells have gained tremendous attention for use in next generation solar cells.

scholarly journals Olive Leaves as Biotemplates for Enhanced Solar-Light Harvesting by a Titania-Based Solid

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1057
Author(s):  
Jesús Hidalgo-Carrillo ◽  
Juan Martín-Gómez ◽  
M. Carmen Herrera-Beurnio ◽  
Rafael C. Estévez ◽  
Francisco J. Urbano ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Average Particle Size ◽  
Solar Irradiation ◽  
Bet Surface Area ◽  
Resonance Spectroscopy ◽  
Average Particle ◽  
Olive Leaves ◽  
Sem Images ◽  
X Ray

Olive leaves (by-product from olive oil production in olive mills) were used as biotemplates to synthesize a titania-based artificial olive leaf (AOL). Scanning electron microscopy (SEM) images of AOL showed the successful replication of trichomes and internal structure channels present in olive leaves. The BET surface area of AOL was 52 m2·g−1. X-ray diffraction (XRD) and Raman spectra revealed that the resulting solid was in the predominantly-anatase crystalline form (7.5 nm average particle size). Moreover, the synthesis led to a red-shift in light absorption as compared to reference anatase (gap energies of 2.98 and 3.2 eV, respectively). The presence of surface defects (as evidenced by X-ray photoelectron spectroscopy, XPS, and electron paramagnetic resonance spectroscopy, EPR) and doping elements (e.g., 1% nitrogen, observed by elemental analysis and XPS) could account for that. AOL was preliminarily tested as a catalyst for hydrogen production through glycerol photoreforming and exhibited an activity 64% higher than reference material Evonik P25 under solar irradiation and 144% greater under ultraviolet radiation (UV).

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.

Facile Synthesis and Characterization of Spinel NiFe2O4 Nanoparticles and Studies of Their Photocatalytic Activity for Oxidation of Alcohols

2020 ◽  
Vol 12 (3) ◽  
pp. 357-365 ◽  
Author(s):  
Xiangrong Ma ◽  
Rui Dang ◽  
Jieying Liu ◽  
Fang Yang ◽  
Huigui Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Bet Analysis ◽  
Oxidation Of Alcohols ◽  
20 Nm ◽  
Adsorption Desorption

In this paper, we report a novel and facile approach for the synthesis of spinel NiFe2O4 nanoparticles and studies of its photocatalytic activity for oxidation of alcohols. The as-synthesized catalyst was thoroughly characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental mapping, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and N2 adsorption–desorption isotherm (BET) analysis. The TEM image reveals cubic shapes with an average particle size of 10–20 nm. The as-synthesized spinel NiFe2O4 has proved to be an excellent photocatalyst for oxidation of alcohol to the aldehyde with a conversion of 80% and selectivity of 99%. The catalyst has also proved to be noteworthy as it does not loss its catalytic activity even after five cycles of reuse.

scholarly journals Fabrication, Characterization, and Optimization of CdS and CdSe Quantum Dot-Sensitized Solar Cells with Quantum Dots Prepared by Successive Ionic Layer Adsorption and Reaction

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
H. K. Jun ◽  
M. A. Careem ◽  
A. K. Arof
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Solar Cell Performance ◽  
Optimum Performance ◽  
Layer Adsorption ◽  
Cdse Quantum Dot ◽  
Sensitized Solar Cells ◽  
Ionic Layer ◽  
Dipping Time

CdS and CdSe quantum dot-sensitized solar cells (QDSSCs) were used for the study of determining the optimum preparation parameters that could yield the best solar cell performance. The quantum dots (QDs) were coated on the surface of mesoporous TiO2layer deposited on FTO substrate using the successive ionic layer adsorption and reaction (SILAR) method. In this method the QDs are allowed to grow on TiO2by dipping the TiO2electrode successively in two different solutions for predetermined times. This method allows the fabrication of QDs in a facile way. Three preparation parameters that control the QD fabrication were investigated: concentration of precursor solutions, number of dipping cycles (SILAR cycles), and dipping time in each solution. CdS based QDSSC showed optimum performance when the QDs were prepared from precursor solutions having the concentration of 0.10 M using 4 dipping cycles with the dipping time of 5 minutes in each solution. For CdSe QDSSC, the optimum performance was achieved with QDs prepared from 0.03 M precursor solutions using 7 dipping cycles with 30 s dipping time in each solution. The QDs deposited on TiO2surface were characterized using UV-vis absorption spectroscopy, FESEM, and TEM imaging.

Preparation, characterization and dechlorination property of nano Pd-Ni/γ-Al2O3 bimetallic catalyst

2019 ◽  
Vol 12 (06) ◽  
pp. 1951003 ◽  
Author(s):  
Yu Zhang ◽  
Yiyang Wang ◽  
Yalong Liao ◽  
Muyuan Guo ◽  
Gongchu Shi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Bimetallic Catalyst ◽  
Average Particle Size ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Emission Spectrometry ◽  
Average Particle ◽  
Plasma Atomic Emission Spectrometry ◽  
X Ray

Nano Pd-Ni/[Formula: see text]-Al2O3 bimetallic catalyst was prepared by chemical precipitation method enhanced with ultrasonic wave. The influence of dosage of dispersant, ultrasonic intensity and mass ratio of Pd to Ni on the dechlorination property of the catalyst obtained was investigated in detail. The appearance morphology, composition and structure of the catalysts prepared were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption, while the specific surface area was determined using the Brunauer–Emmett–Teller (BET) isotherm and the chemical composition of active gradients was tested with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Results indicate that the nano Pd-Ni/[Formula: see text]-Al2O3 bimetallic catalyst prepared has uniform distribution of active ingredients with an average particle size of 4.91[Formula: see text]nm, and the chlorine content of shellac dechlorinated with the catalyst obtained is 0.34[Formula: see text]wt.% which is lower than that reported in the literature, meaning the perfect dechlorination property of the catalyst.

scholarly journals Effect of Synthesis Method on Antibacterial and Antibiofilm Activity Properties of BaFeO3-δ Perovskite Nanomaterials

2021 ◽  
Author(s):  
eid khalaf ◽  
E. K. Abdel-Khalek ◽  
Ahmed. A. Askar ◽  
M. A. Motawea ◽  
Mohamed A. Aboelnasr ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Rietveld Analysis ◽  
Antibiofilm Activity ◽  
Average Particle ◽  
X Ray ◽  
Valence States ◽  
Fe Ions

Abstract BaFeO3-δ perovskite nanomaterials have been synthesized by two different methods: co-precipitation (Cop) and sol-gel (Sol) methods. Rietveld analysis of the X-Ray diffraction (XRD) shows that the samples are crystallized in rhombohedral perovskite structure with space group R3c. Scanning electron microscope (SEM) of these samples showed the agglomerations of various particles. Dynamic light scattering (DLS) showed that the average particle size of BaFeO3-Cop sample is larger than that of BaFeO3-Sol sample. The amount of oxygen deficient (δ) and the valence states of Fe ions in these samples were determined from Mössbauer spectroscopy. X-ray photoelectron spectroscopy (XPS) shows the elemental compositions and surface electronic states of these samples. The thermal, optical and magnetic properties of these samples depend on the amount of oxygen deficient (δ) and the valence states of Fe ions. Furthermore, the antibacterial and antibiofilm activity of these samples was systematically investigated. The present results suggest that BaFeO3-δ superparamagnetic perovskite can be used as antibacterial and antibiofilm agent.

scholarly journals In-flight Synthesis of Nanosized ZrC Particles from Various Precursors in RF Thermal Plasma

2021 ◽  
Author(s):  
Alejandro Martiz ◽  
Zoltán Károly ◽  
Eszter Bódis ◽  
Péter Fazekas ◽  
Miklós Mohai ◽  
...  
Keyword(s):  
Thermal Plasma ◽  
Photoelectron Spectroscopy ◽  
Average Particle Size ◽  
Reaction System ◽  
Spherical Shape ◽  
Molar Ratio ◽  
Average Particle ◽  
X Ray ◽  
Temperature Range ◽  
Rf Thermal Plasma

Synthesis of zirconium carbide (ZrC) powder was investigated applying a non-conventional atmospheric radiofrequency (RF) thermal plasma process. In one case, zirconium dioxide (ZrO2) was reacted with solid carbon or with methane with varying molar ratio. In the other, zirconium-propoxide (NZP), containing both constituents, was thermally decomposed in the Ar plasma. Temperature-dependent thermodynamic analysis was performed in the 500-5500 K temperature range to estimate the formation of possible equilibrium products for each reaction stoichiometry. Broad temperature range exists for the stability of solid ZrC for each explored reaction system. In accordance with this prediction, X-ray diffraction studies detected the ZrC as the major phase in all the prepared powders. The yield of particular runs ranged from 39 % to 98 %. Practically, full conversion was typical for the case of NZP precursor, however only partial conversion could be detected in ZrO2 reactions. The average particle size of the powders falls between 10 nm and 100 nm depending on the type of the reaction systems (either calculated from the specific surface area or derived from broadening the XRD reflections). The transmission electron micrographs indicated mostly globular shape of the nanosize particles. Quantitative analysis of the surface of the powders by X-ray photoelectron spectroscopy revealed the presence of oxygen and carbon. Evaluating the spectra of the powders prepared from NZP, and taking in the account its spherical shape, a ZrC core covered by a very thin (≈1.0 nm) ZrO2 layer may be accounted for the measured oxygen and a thicker carbonaceous layer.

Formation features of zink titanate by electric explosion dispersion of titanium and zinc wires in an oxygen-containing atmosphere

2021 ◽  
pp. 38-43
Author(s):  
O.V. Bakina ◽  
◽  
N.V. Svarovskaya ◽  
A.V. Pervikov ◽  
V.R. Chzhou ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Photoelectron Spectroscopy ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Decomposition Reaction ◽  
Electric Explosion ◽  
Average Particle ◽  
Zinc Titanate ◽  
X Ray ◽  
High Antibacterial Activity

In present work, we have synthesized, for the first time, zinc titanate nanoparticles by electric explosion of titanium and zinc wires in an oxygen-containing atmosphere (argon - oxygen 20 vol. %). As-synthesized nanoparticles nanoparticles were characterized using transmission electron microscopy, X-ray analysis, and X-ray photoelectron spectroscopy. The particles have a spherical shape and an average particle size of 82 nm. The phase composition is presented by zinc titanate and a small amount of titanium oxide, which corresponds to the phase diagram of the TiO2-ZnO system. The photocatalytic activity of the synthesized nanoparticles was studied in the decomposition reaction of a model dye methylene blue and it was found that it was higher than that of titanium oxide nanoparticles obtained by electric explosion of a titanium wire in an oxygen-containing atmosphere. In addition, the synthesized nanoparticles demonstrated high antibacterial activity against MRSA bacteria.

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