Synthesis and Characterization of Copper (I) Chloride (CuCl) Nanocrystals in Conductive Polymer for UV Light Emitters

2010 ◽  
Vol 1247 ◽  
Author(s):  
M. M. Alam ◽  
F. Olabanji Lucas ◽  
A. Cowley ◽  
Karl Crowley ◽  
S. Daniels ◽  
...  
Keyword(s):  
Room Temperature ◽  
Uv Light ◽  
Conductive Polymer ◽  
X Ray Diffraction ◽  
Light Emitters ◽  
Glass Substrates ◽  
Excitonic Absorption ◽  
Coating Method ◽  
Average Size ◽  
Cucl Nanocrystals

AbstractIntrinsic γ-Copper (I) Chloride is an ionic I-VII compound semiconductor material with relatively low conductivity. To fabricate an efficient electroluminescent device based on CuCl nanocrystals (NC) the conductivity of the CuCl NC film should be relatively high. In order to improve the conductivity of CuCl films, nanocrystals were embedded in a highly conductive polymer (Polyaniline) and deposited on glass substrates via the spin-coating method. The deposited films were heated at 140°C for durations between 1 and 12 hours in vacuo. The room temperature UV-Vis absorption spectra for all CuCl films showed both Z1,2 and Z3 excitonic absorption features and the absorption intensity increased as the anneal time increased. Room temperature photoluminescence (PL) measurements of the hybrid films reveal very intense Z3 excitonic emission. Room temperature X-ray diffraction (XRD) confirmed the preferential growth of CuCl nanocrystals whose average size is ≈40 nm in the <111> orientation. Resistivity measurements were carried out using a four-point probe system, which confirmed that the resistivity of the composite film was ≈500 Ω/cm. This is an improvement when compared to the vacuum evaporated CuCl thin films.

Optical Properties of Nanostructured Sol–Gel Thin Films Doped with Fe2O3 and Their Ferromagnetic Characterization by Mössbauer Spectroscopy

2008 ◽  
Vol 8 (12) ◽  
pp. 6491-6496
Author(s):  
Jorge Garcia-Macedo ◽  
Guadalupe Valverde-Aguilar ◽  
Raúl W. Gómez ◽  
José L. Pérez-Mazariego ◽  
Vivianne Marquina
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
Optical Quality ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Coating Method ◽  
Dip Coating Method

Sol–gel thin films containing Fe2O3 were deposited onto glass substrates by the dip-coating method at room temperature. Fe2O3 enriched with the isotope 57Fe was embedded in two kinds of matrices: zinc oxide (ZnO) and silica (SiO2). X-ray diffraction (XRD) was used for morphology and structure determination of the nanostructures and showed that the ZnO exhibit a wurtzite form when the film is annealed at 450 °C for 20 min. SiO2 thin films at C16H33PEO20:Fe2O3 = 1:2.7 × 10−1 molar concentration exhibit a hexagonal nanophase produced by the diblock copolymer Brij58 (C16H33PEO20). Optical absorption and infrared spectroscopy techniques were used to evaluate the optical quality of the films. In order to determine if the Fe2O3 was incorporated into the matrices, room temperature Mössbauer spectra of both samples were obtained. In both cases the hematite spectrum was obtained, corroborating that the incorporation of the Fe2O3 to the matrices was done without chemical reaction whatsoever.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

scholarly journals Compositional Dependence of Structural Properties of Prepared Alloys and Films

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
M. F. A. Alias ◽  
A. A. J. Al-Douri ◽  
E. M. N. Al-Fawadi ◽  
A. A. Alnajjar
Keyword(s):  
Room Temperature ◽  
Thermal Evaporation ◽  
High Accuracy ◽  
Compositional Dependence ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Good Agreement

Results of a study of alloys and films with various Pb content have been reported and discussed. Films of of thickness 1.5 μm have been deposited on glass substrates by flash thermal evaporation method at room temperature, under vacuum at constant deposition rate. These films were annealed under vacuum around 10−6Torr at different temperatures up to 523 K. The composition of the elements in alloys was determined by standard surfaces techniques such as atomic absorption spectroscopy (AAS) and X-ray fluorescence (XRF), and the results were found of high accuracy and in very good agreement with the theoretical values. The structure for alloys and films is determined by using X-ray diffraction. This measurement reveals that the structure is polycrystalline with cubic structure and there are strong peaks at the direction (200) and (111). The effect of heat treatment on the crystalline orientation, relative intensity, and grain size of films is presented.

scholarly journals Study of NO2 Sensing Properties of UV-Activated Graft Comb Copolymer and ZnO Blends in ppm and Sub-ppm Range at Room Temperature

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 82
Author(s):  
Piotr Kałużynski ◽  
Marcin Procek ◽  
Agnieszka Stolarczyk
Keyword(s):  
Room Temperature ◽  
Uv Light ◽  
Side Chain ◽  
Chloroform Fraction ◽  
Carrier Gas ◽  
Response Characteristics ◽  
Fraction H ◽  
Coating Method ◽  
Comb Copolymer ◽  
Wide Potential

In this work, a novel organic-inorganic blend made from PEGSil (Poly(dimetylsiloksan)-co-[poli(metylohydrosiloksane)-graft-2-winyl-poly(3-heksylthiophene)]-co-[poly(dimetylsiloksane)-graft- metakrylane ethere metylene poly(etylene glicole)]]) mixed with zinc oxide nanomaterial was studied as the sensitive layer for nitrogen dioxide (NO2) resistance gas sensor application. Moreover, the PEGSil graft copolymer material was tested in two variants, defined by side-chain length of P3HT: shorter hexane fraction (H) and longer chloroform fraction (CH). Elaborated organic–inorganic blend was deposited on interdigital transducers (Au on Si/SiO2) by the drop coating method from a chlorobenzene-based mixture. Sensor response characteristics to different concentrations of NO2 (1–10 ppm) in N2 carrier gas and synthetic air were measured and compared. Measurements were done at room temperature with UV light charge carriers’ activation. Moreover, measurements for low gas concentrations (50–500 ppb) were made and analyzed. The obtained results show that the sensitivity of fabricated sensors is about 6.8% per 1 ppb for hexane fractions of PEGSil and 9.3% for chloroform fractions in the concentration range from 50 to 200 ppb NO2 in N2 carrier gas. These results show that the blend of these materials has wide potential as a sensing layer for NOx low-concentration sensing.

IMPROVED PROPERTIES OF SnO2 THIN FILMS OBTAINED VIA SPIN COATING METHOD BY VARYING THE SOLUTION CONCENTRATION

2018 ◽  
Vol 25 (04) ◽  
pp. 1850092
Author(s):  
SOUMIA BELHAMRI ◽  
NASR-EDDINE HAMDADOU
Keyword(s):  
Spin Coating ◽  
Visible Spectrum ◽  
Optical Transmittance ◽  
Solution Concentration ◽  
X Ray Diffraction ◽  
Film Properties ◽  
Average Roughness ◽  
Arithmetic Average ◽  
Glass Substrates ◽  
Coating Method

The aim of this work is to study the solution concentration effect on the SnO2 thin film properties, which were deposited on glass substrates by spin coating technique and annealed for one hour at 500[Formula: see text]C. X-ray diffraction (XRD) spectra show that the films deposited at various solution concentrations (0.5[Formula: see text]mol/L, 0.7[Formula: see text]mol/L and 1[Formula: see text]mol/L) are polycrystalline with a tetragonal rutile type. Grains have two preferred orientations along the directions (110) and (101) corresponding to 2[Formula: see text] equal to 26.74[Formula: see text] and 34.11[Formula: see text], respectively. We have also noted that the grain size changes between 109[Formula: see text]nm and 178[Formula: see text]nm. However, the film coated at 10 deposition cycles and 0.7[Formula: see text]mol/L solution concentration has a minimum arithmetic average roughness of 0.376 nm. The optical transmittance of the films in the visible spectrum was in the range of 77–84% and the optical band gap gradually decreases with the decrease of the solution concentration from 4.11[Formula: see text]eV to 3.56[Formula: see text]eV.

Structure and Electronic Properties of Evaporated Thin Films of Lead Sulfide

2009 ◽  
Vol 294 ◽  
pp. 85-92 ◽  
Author(s):  
A.A. Ibrahim
Keyword(s):  
Thin Films ◽  
Lead Sulfide ◽  
Room Temperature ◽  
Conduction Band Edge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Temperature Electron ◽  
Transition Voltage ◽  
Dc Electrical Properties

Lead sulfide (PbS) thin films were prepared by thermal evaporation onto glass substrates from PbS powder. The structure and DC electrical properties of evaporated PbS thin film sandwich structures with thicknesses (d) up to 600 nm have been investigated. X-ray diffraction studies showed that the films were crystalline, with a preferred orientation in the [111] direction. Capacitance measurements indicated that the films had a relative permittivity of 5.7. Room-temperature current density-voltage (J–V) characteristics revealed ohmic conduction below a transition voltage (Vt) and a power–law dependence with an exponent of ≈ 2 at higher voltages. This behaviour was interpreted in terms of space–charge limited conductivity controlled by an exponential distribution of traps below the conduction band edge. Further evidence for this conduction process was provided by a linear dependence of Vt upon d2. Analysis of the results yielded a room temperature electron concentration no of ≈ (3.9 – 5.4) x 109 m-3.

Synthesis and Characterization of Superparamagnetic NiFe2O4 Nanoparticles

2010 ◽  
Vol 663-665 ◽  
pp. 1325-1328 ◽  
Author(s):  
De Hui Sun ◽  
De Xin Sun ◽  
Yu Hao
Keyword(s):  
Room Temperature ◽  
Size Range ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
Cubic Crystal ◽  
Xrd Pattern ◽  
X Ray ◽  
Nife2o4 Nanoparticles ◽  
Average Size

The superparamagnetic NiFe2O4 nanoparticles were synthesized using a hydrothermal technology through P123 sphere micelles as ‘nanoreactor’ in this work. Their morphologies, structures, surface properties and magnetism were characterized by FE-SEM, XRD, FTIR, and VSM, respectively. The nickel ferrite samples are nearly spherical and homogeneous nanoparticles with average size range of about 50-120 nm. They possess superparamagnetism at room temperature and higher saturation magnetization. X-ray diffraction (XRD) pattern confirms that the samples belong to the cubic crystal system with an inverse-spinel structure. Fourier transform infrared (FTIR) absorption spectrum indicates that the NiFe2O4 nanoparticles are stabilized by the P123 adsorbed on the surface of nanoparticles.

Hydrothermal Synthesis and Photoluminescence Properties of Ca(MoO4)x(WO4)(1-X) Microcrystallines

2013 ◽  
Vol 652-654 ◽  
pp. 599-606
Author(s):  
Yan Zhao ◽  
Yan Yan Wei ◽  
Dan Qin ◽  
Xin Lai ◽  
Yun Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Uv Light ◽  
Emission Spectra ◽  
Fluorescence Analysis ◽  
Tetragonal Symmetry ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Structure Surface ◽  
Ft Ir

Ca(MoO4)x(WO4)(1-x)solid solution microcrystallines were synthesized by hydrothermal method at 120 °C; the crystal structure, surface morphology and room temperature photoluminescence properties of the as-synthesized microcrystallines were investigated by through X-ray diffraction (XRD), scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FT-IR) and fluorescence analysis (FA), respectively. Our results show that the obtained Ca(MoO4)x(WO4)(1-x)microcrystallines are single-phase scheelite structure with tetragonal symmetry. The grain size of the Ca(MoO4)x(WO4)(1-x) microcrystallines gradually increases with the increasing x (except x=0) and their agglomeration also becomes serious with x increasing. Under excited by 245 nm or 280 nm ultraviolet light (UV-light) at room temperature, the emission spectra of the Ca(MoO4)x(WO4)(1-x) microcrystallines vary slightly from 410nm to 490nm with increasing x. Whereas the emission intensity of Ca(MoO4)x(WO4)(1-x) microcrystallines changed markedly, and it increases with the increasing x (x＞0).

scholarly journals Surface Modified Ni Nanoparticles Produced by the Electrical Explosion of Wire

2015 ◽  
Vol 233-234 ◽  
pp. 513-516 ◽  
Author(s):  
A.P. Safronov ◽  
Galina V. Kurlyandskaya ◽  
S.M. Bhagat ◽  
I.V. Beketov ◽  
A.M. Murzakaev ◽  
...  
Keyword(s):  
Room Temperature ◽  
Electrical Explosion ◽  
Resonant Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Transmission Electron ◽  
Average Size ◽  
Surface Modified ◽  
Made In

Spherical nickel nanoparticles were prepared by the electrical explosion of wire. The as-prepared nanoparticles were modified immediately after fabrication at room temperature in order to provide tunable surface properties with focus on the development of composites filled with nanoparticles. Following liquid modificators were used: hexane, toluene and the solution of polystyrene in toluene. In one case the surface modification by carbon was made in gas phase as a result of hydrocarbon injection. The average size of the nanoparticles was about 50 nm and unit cell parameters were close to 0.351 nm. Detailed characterization was done by X-ray diffraction, transmission electron microscopy, and magnetization measurements. Sphericity was also checked using microwave resonant absorption.

Self-Cleaning TiO2/SiO2 Thin Film Prepared by a Simple Sol-Gel Method

2014 ◽  
Vol 804 ◽  
pp. 157-160
Author(s):  
Wen Xiu Liu ◽  
Jun Na Xu ◽  
Jun Zhang ◽  
Xue Mei Liu ◽  
Wen Bin Cao
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Sulfate Solution ◽  
Ultraviolet Region ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Titanyl Sulfate ◽  
Glass Substrates ◽  
Light Region ◽  
Vis Spectroscopy

TiO2 thin films were prepared on SiO2-coated glass substrates using sols deriving from high concentration titanyl sulfate solution by the spin-coating technique. The calcined films were characterized by X-ray diffraction, UV-Vis spectroscopy, scanning electron microscopy. The film exhibited high transmittance in the visible light region and high absorption in the ultraviolet region. The contact angle of SiO2/TiO2 decreased to below 5° under 30 min of UV light irradiation and can sustain for 1 weeks.

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