Preparation, structural investigation and optical properties determination of composite films based on PAZO polymer doped with GeTe4-Cu chalcogenide particles

2021 ◽  
Author(s):  
Ani Stoilova ◽  
Dean Dimov ◽  
Yordanka Trifonova ◽  
Vanya Lilova ◽  
Blaga Blagoeva ◽  
...  
Keyword(s):  
Optical Properties ◽  
Structural Investigation ◽  
Bulk Material ◽  
Composite Films ◽  
Optical Absorption Coefficient ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Reflectance Coefficient ◽  
Diode Pumped

The work presents preparation, structural investigation and optical properties characterization of composite films based on the azopolymer (poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2- ethanediyl, sodium salt]), shortly PAZO, doped with 1 wt.% particles of the previously synthesized by us new tellurium containing chalcogenide system (GeTe4)100-xCux, where x = 5, 10, 15 and 20 mol.%. X-Ray diffraction (XRD) was applied to analyze the structure of the chalcogenide bulk material. Transmission electron microscopy (TEM) has been used to study the particles and the composite films morphology. The transmittance coefficient (T), the reflectance coefficient (R), the refractive index (n), the extinction coefficient (k), the optical absorption coefficient (α) and the optical band gap (E_g^opt) of the composite films were determined. Birefringence was induced by a He-Cd laser with a wavelength 442 nm and measured with probe Diode Pumped Solid State (DPSS) laser at 635 nm. The influence of the dopants concentration on the optical performance of the composite films has been discussed.

scholarly journals Temperature Dependence of Stress and Optical Properties in AlN Films Grown by MOCVD

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 698
Author(s):  
Wenwang Wei ◽  
Yi Peng ◽  
Jiabin Wang ◽  
Muhammad Farooq Saleem ◽  
Wen Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Compressive Stress ◽  
Sapphire Substrate ◽  
Light Transmission ◽  
Chemical Vapor ◽  
Biaxial Stress ◽  
X Ray Diffraction ◽  
Patterned Sapphire Substrate ◽  
Transmission Electron ◽  
Nano Patterning

AlN epilayers were grown on a 2-inch [0001] conventional flat sapphire substrate (CSS) and a nano-patterned sapphire substrate (NPSS) by metalorganic chemical vapor deposition. In this work, the effect of the substrate template and temperature on stress and optical properties of AlN films has been studied by using Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible spectrophotometer and spectroscopic ellipsometry (SE). The AlN on NPSS exhibits lower compressive stress and strain values. The biaxial stress decreases from 1.59 to 0.60 GPa for AlN on CSS and from 0.90 to 0.38 GPa for AlN on NPSS sample in the temperature range 80–300 K, which shows compressive stress. According to the TEM data, the stress varies from tensile on the interface to compressive on the surface. It can be deduced that the nano-holes provide more channels for stress relaxation. Nano-patterning leads to a lower degree of disorder and stress/strain relaxes by the formation of the nano-hole structure between the interface of AlN epilayers and the substrate. The low crystal disorder and defects in the AlN on NPSS is confirmed by the small Urbach energy values. The variation in bandgap (Eg) and optical constants (n, k) with temperature are discussed in detail. Nano-patterning leads to poor light transmission due to light scattering, coupling, and trapping in nano-holes.

scholarly journals Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

2016 ◽  
Vol 7 ◽  
pp. 1492-1500 ◽  
Author(s):  
Ionel Stavarache ◽  
Valentin Adrian Maraloiu ◽  
Petronela Prepelita ◽  
Gheorghe Iordache
Keyword(s):  
Optical Properties ◽  
Response Time ◽  
Spectral Width ◽  
Fast Response ◽  
Superior Performance ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Preparation Conditions ◽  
Photoelectric Properties ◽  
Transmission Electron

Obtaining high-quality materials, based on nanocrystals, at low temperatures is one of the current challenges for opening new paths in improving and developing functional devices in nanoscale electronics and optoelectronics. Here we report a detailed investigation of the optimization of parameters for the in situ synthesis of thin films with high Ge content (50 %) into SiO2. Crystalline Ge nanoparticles were directly formed during co-deposition of SiO2 and Ge on substrates at 300, 400 and 500 °C. Using this approach, effects related to Ge–Ge spacing are emphasized through a significant improvement of the spatial distribution of the Ge nanoparticles and by avoiding multi-step fabrication processes or Ge loss. The influence of the preparation conditions on structural, electrical and optical properties of the fabricated nanostructures was studied by X-ray diffraction, transmission electron microscopy, electrical measurements in dark or under illumination and response time investigations. Finally, we demonstrate the feasibility of the procedure by the means of an Al/n-Si/Ge:SiO2/ITO photodetector test structure. The structures, investigated at room temperature, show superior performance, high photoresponse gain, high responsivity (about 7 AW−1), fast response time (0.5 µs at 4 kHz) and great optoelectronic conversion efficiency of 900% in a wide operation bandwidth, from 450 to 1300 nm. The obtained photoresponse gain and the spectral width are attributed mainly to the high Ge content packed into a SiO2 matrix showing the direct connection between synthesis and optical properties of the tested nanostructures. Our deposition approach put in evidence the great potential of Ge nanoparticles embedded in a SiO2 matrix for hybrid integration, as they may be employed in structures and devices individually or with other materials, hence the possibility of fabricating various heterojunctions on Si, glass or flexible substrates for future development of Si-based integrated optoelectronics.

scholarly journals Fabrication of a Food Nano-Platform Sensor for Determination of Vanillin in Food Samples

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2817 ◽  
Author(s):  
Vinod Gupta ◽  
Hassan Karimi-Maleh ◽  
Shilpi Agarwal ◽  
Fatemeh Karimi ◽  
Majede Bijad ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Food Samples ◽  
Precipitation Method ◽  
Single Wall Carbon Nanotubes ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Paste Electrode

Herein, we describe the fabrication of NiO decorated single wall carbon nanotubes (NiO-SWCNTs) nanocomposites using the precipitation method. The synthesized NiO-SWCNTs nanocomposites were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Remarkably, NiO-SWCNTs and 1-butylpyridinium hexafluorophosphate modified carbon paste electrode (CPE/NiO-SWCNTs/BPrPF6) were employed for the electrochemical detection of vanillin. The vanillin sensor showed an ultra-high sensitivity of 0.3594 μA/μM and a low detection limit of 0.007 μM. In the final step, the NiO-SWCNTs/BPrPF6 was used as the suitable tool for food analysis.

scholarly journals New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

2015 ◽  
Vol 11 ◽  
pp. 1175-1186 ◽  
Author(s):  
Rym Hassani ◽  
Mahjoub Jabli ◽  
Yakdhane Kacem ◽  
Jérôme Marrot ◽  
Damien Prim ◽  
...  
Keyword(s):  
Optical Properties ◽  
Spectroscopic Analysis ◽  
Palladium Complexes ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Enantiomerically Pure ◽  
One Step ◽  
Uv Visible ◽  
High Yields

The present paper describes the synthesis of new palladium–oxazoline complexes in one step with good to high yields (68–95%). The oxazolines were prepared from enantiomerically pure α-aminoalcohols. The structures of the synthesized palladium complexes were confirmed by NMR, FTIR, TOFMS, UV–visible spectroscopic analysis and X–ray diffraction. The optical properties of the complexes were evaluated by the determination of the gap energy values (E g) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C 0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also determined.

scholarly journals Synthesis and optical properties of self-assembled flower-like CdS architectures by mixed solvothermal process

2010 ◽  
Vol 8 (5) ◽  
pp. 1027-1033 ◽  
Author(s):  
Junhao Zhang ◽  
Yuhui Wu ◽  
Jia Zhu ◽  
Shaoxing Huang ◽  
Dongjing Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
X Ray Diffraction ◽  
Wurtzite Phase ◽  
Strong Emission ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Self Assembled ◽  
Xrd Patterns ◽  
Hexagonal Wurtzite Phase

AbstractSelf-assembled CdS architectures with flower-like structures have been synthesized by a mixed solvothermal method using ethylene glycol and oleic acid as the mixed solvent at 160°C for 12 h. The results of X-ray diffraction (XRD) patterns, field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images indicate that the product exists as the hexagonal wurtzite phase and conatins of larger numbers of flower-like CdS architectures with diameters of 1.8–3 μm. The selected-area electron diffraction (SAED) pattern and the high resolution transmission electron microscope (HRTEM) image reveal that the grain has better crystallinity. The optical properties of flower-like CdS architectures were also investigated by ultraviolet-visable (UV-vis) and photoluminescence spectroscopy at room temperature. A strong peak at 490 nm is shown in the UV-vis absorption, while an emission at 486 nm and another strong emission at 712 nm are shown in the PL spectrum.

scholarly journals Structural characterization of Yba2Cu3O7–δ/Y2O3 composite films

1998 ◽  
Vol 13 (4) ◽  
pp. 954-958 ◽  
Author(s):  
P. R. Broussard ◽  
M. A. Wall ◽  
J. Talvacchio
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Coincidence Site Lattice ◽  
Composite Films ◽  
X Ray Diffraction ◽  
Plane Orientation ◽  
Transmission Electron ◽  
Two Phases ◽  
High Degree

Using 4-circle x-ray diffraction and transmission electron microscopy, we have studied the microstructure and in-plane orientation of the phases present in thin film composite mixtures of Yba2Cu3O7–δ and Y2O3. We see a high degree of in-plane orientation and have verified a previous prediction for the in-plane order of Y2BaCuO5 on (110) MgO. Transmission electron microscopy shows the composite films to be a mixture of two phases, with YBCO grain sizes of ≈1 μm. We have also compared our observations of the in-plane order to the predictions of a modified near coincidence site lattice model.

scholarly journals Sonochemical Synthesis and Properties of YVO4:Eu3+ Nanocrystals for Luminescent Security Ink Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Chinh Dung Trinh ◽  
Phuong Thi Pham Hau ◽  
Thi My Dung Dang ◽  
Chien Mau Dang
Keyword(s):  
Electron Microscopy ◽  
Bulk Material ◽  
Sonochemical Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Electrohydrodynamic Printing ◽  
Security Label ◽  
Wet Chemical ◽  
Security Property ◽  
The Eu

Solutions and redispersible powders of nanocrystalline, europium-doped YVO4, are prepared via a wet chemical method using the ultrasonic processor (sonochemical) and microwave and thermal stirring. From X-ray diffraction (XRD) results, YVO4:Eu3+ nanoparticles synthesized using sonochemical method have better crystallinity than those prepared using thermal stirring and microwave methods exhibiting the tetragonal structure known for bulk material. From field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results, it is found that the size of nanoparticles is around 25 nm and increasing after annealing at 900°C. From UV-Vis result, there is a peak at 270 nm corresponding to the absorption of VO43− groups. The photoluminescence (PL) results clearly show the strongest red emission peak at the wavelength around 618 nm. The highest luminescent intensity is obtained for the sample prepared by the sonochemical method at pH = 12 and annealing temperature at 900°C for 4 h. The average lifetimes of the Eu3+ ions in the samples annealed at 300, 600, and 900°C for 1 h at 618 nm emission under 275 nm excitation are 0.36, 0.62, and 0.64 ms, whereas sample annealed at 900°C for 4 h has lifetime of 0.70 ms. The security ink, containing synthesized YVO4:Eu3+ nanoparticles, is dispersed in glycerol and other necessary solvents. The experimental security labels are printed by inkjet using the electrohydrodynamic printing technique. The resulting lines represented to the security labels are analyzed by the 3D microscope equipment and UV 20 W mercury lamp with a wavelength of ∼254 nm. The seamless line of the printed security label has the value of the width at ∼230 μm, thickness at ∼0.68 μm, and distance between two adjacent lines at 800 μm. This result is compatible for producing security labels in small size (millimeter) in order to increase security property.

CONTROLLED SYNTHESIS OF THE ZnWO4 NANOSTRUCTURE AND STUDY OF THEIR STRUCTURAL AND OPTICAL PROPERTIES

2012 ◽  
Vol 21 (01) ◽  
pp. 1250002 ◽  
Author(s):  
NGUYEN MANH HUNG ◽  
LAM THI HANG ◽  
NGUYEN VAN KHANH ◽  
DU THI XUAN THAO ◽  
NGUYEN VAN MINH
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Optical Properties ◽  
Reaction Time ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Calcination Time ◽  
Transmission Electron ◽  
Pure Phase ◽  
Size And Morphology

We investigate the effects of calcination time and concentration of solution on the structure, as well as optical properties in ZnWO4 nanopowder prepared by hydrothermal method. The prepared powder were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman scattering, optical absorption and photoluminescent spectroscopy (PL). It is shown that the grain size and morphology of ZnWO4 nanopowder can be controlled by adjusting the reaction time as well as the concentration of the solution. The resultant sample is a pure phase of ZnWO4 without any impurities. The result showed that the optical property of ZnWO4 nanopowders depend on their grain size. The optical band gap becomes narrower as the reaction time or concentration of solution is increased. The improved PL properties of the ZnWO4 crystallites can be obtained with the optimal concentration of the solution.

Laccase Biosensor Based on Ag-Doped TiO2 Nanoparticles on CuCNFs for the Determination of Hydroquinone

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650132 ◽  
Author(s):  
Jie Yang ◽  
Dawei Li ◽  
Zengyuan Pang ◽  
Qufu Wei
Keyword(s):  
Electron Microscopy ◽  
Storage Stability ◽  
Electrochemical Impedance ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
New Material ◽  
And Storage

A novel nanomaterial composed of copper and carbon nanofibers (CuCNFs) decorated with Ag-doped TiO2 (Ag–TiO[Formula: see text] nanoparticles was prepared through electrospinning, carbonization and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The obtained composites were mixed with laccase and Nafion to construct novel hydroquinone biosensor. The electrochemical behavior of the novel biosensor was studied using cyclic voltammetry (CV) and chronoamperometry. The results demonstrated that the biosensor possessed a wide detection linear range (1.20–176.50[Formula: see text][Formula: see text]M), a good selectivity, repeatability, reproducibility and storage stability. This work provides a new material to design more efficient laccase (Lac) based biosensor for hydroquinone detection.

Preparation and photoelectrochemical performance of nano Bi2S3–TiO2 composites

2018 ◽  
Vol 11 (03) ◽  
pp. 1850055 ◽  
Author(s):  
Senlin Li ◽  
Jinliang Huang ◽  
Xiangmei Ning ◽  
Yongchao Chen ◽  
Qingkui Shi
Keyword(s):  
Solvothermal Method ◽  
Composite Films ◽  
Great Influence ◽  
Photocurrent Density ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
Photoelectrochemical Performance ◽  
X Ray ◽  
External Bias ◽  
Transmission Electron

TiO2 nanorod (NR) arrays were prepared on FTO by the simple hydrothermal synthesizing method. On this basis, a layer of Bi2S3 quantum dots (QDs) was covered on the surface of TiO2 NRs array by solvothermal method, by which the Nano Bi2S3/TiO2 NRs composites films were obtained. The phase structure, morphologies, optical absorptions and photoelectrochemical (PEC) properties of the as-prepared materials were characterized by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Ultraviolet–visible spectroscopy (UV-Vis), Photoluminescence (PL) and electrochemical workstation. The results indicate that the concentration of tetrabutyl titanate (TBT) has a great influence on the morphology of the film, with the increase of TBT content, the array of TiO2 NRs changed from loose to tight, and the thin films were cracked when the TBT volume is up to 0.7[Formula: see text]mL; The absorption of the TiO2 NRs array film to the visible light is enhanced significantly when sensitized with Bi2S3 and the absorption wavelength is increased from 400[Formula: see text]nm to 800[Formula: see text]nm. Compared with the pure TiO2, the fluorescence intensity of the TiO2/Bi2S3 NRs is weakened, and there is no obvious fluorescence diffraction peak. Under the irradiation of standard (AM1.5[Formula: see text]G 100[Formula: see text]mW/cm[Formula: see text], the photocurrent density of the composite film increased significantly. When the external bias voltage is 1.2[Formula: see text]V, the current density of the composite films is five times of that of the pure TiO2.

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