Effect of CdS Thickness on the Optical and Structural Properties of TiO2/CdS Nanocomposite Film

2015 ◽  
Vol 1107 ◽  
pp. 547-552 ◽  
Author(s):  
Ali Kamel Mohsin ◽  
Noriah Bidin

Efficient modification of energy band gap to absorb visible light in TiO2 semiconductor nanocomposites is challenging. The effect of the varying CdS thickness (50-100 nm) on the structural and optical properties of TiO2/CdS nanocomposite films (NCF) grown by electron beam deposition is reported. The surface morphology and optical behaviors are characterized via XRD, AFM and UV-Vis measurements. The lattice parameters and nanocrystallinity of TiO2/CdS NCF determined from XRD patterns are found to increase gradually with the increase of CdS thickness. The mean particles size estimated using Scherer formula and AFM micrographs lies in the range of 10.29 -59.71 nm for various CdS thickness. The increase in root mean square roughness with the increase of CdS thickness is revealed by AFM micrographs. The UV-Vis measurement shows a significant enhancement in the absorption of NCFs in the range of 340 to 500 nm due to the addition of a small portion of CdS. Interestingly, Our results suggest that the optical and structural properties of TiO2 films can significantly be improved and finely tuned by varying the thicknesses of CdS film useful for applications.

2015 ◽  
Vol 819 ◽  
pp. 215-219
Author(s):  
L.S. Chuah ◽  
Z. Hassan

Annealing of Zn foils substrates was performed in air for 30 min at 300 oC, 400 oC and 500 oC, respectively. The effects of annealing on the structural and optical properties of Zn foils substrates were investigated using X-ray diffraction (XRD), and photoluminescence (PL) measurements. After annealing, the XRD patterns showed that the annealed ZnO films have c-axis preferential orientation, the crystallinity of the ZnO films was improved, and the grain size decreased by thermal annealing. PL spectra are clearly visible at 376 nm for ZnO film grown on Zn foils substrates. The mean grain size in the annealed ZnO microstructures was estimated using Scherrer’s equation is about 82, 76, 69 nm for 300°C, 400°C, and 500°C, respectively. A PL spectrum is clearly visible at 376 nm for ZnO microstructures grown on Zn foil substrates. The PL analysis indicates that the growth of ZnO thin film with the presence of the defect-related band. Green-yellow band emission is observed at 520 nm.


2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 503-508
Author(s):  
M. S. Karmous ◽  
W. Oueslati ◽  
H. Ben Rhaiem ◽  
J. L. Robert ◽  
A. Ben Haj Amara

2010 ◽  
Vol 150-151 ◽  
pp. 1409-1412 ◽  
Author(s):  
Tao Jiang

The Fe3Al/Al2O3 composites were fabricated by pressureless sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3 powders were mixed and the Fe3Al/Al2O3 composite powders were prepared, so the Fe3Al/Al2O3 composites were fabricated by sintering process at 1700oC for 2h. The phase composition and microstructure of Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical properties of the Fe3Al/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The Fe3Al/Al2O3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix, the mean particles size of Fe3Al intermetallics was about 3-5μm. The Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness (HRA) of the Fe3Al/Al2O3 composites decreased gradually with the increase of Fe3Al content.


2021 ◽  
Vol 16 (2) ◽  
pp. 281-287
Author(s):  
Alaa Y. Mahmoud

The effect of the volumetric ratio of the tris(8-hydroxyquinoline) aluminum (Alq3) on its blend with the N,N'-Di [(1-naphthyl)-N,N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (NPD) (Alq3:NPD) is investigated and optimized for the UV photodetectors fabrication. The optical and structural properties of Alq3:NPD blend with different volumetric ratios 1:1, 2:1, and 3:1 is studied in the context of the absorbance, transmittance, optical energy gap and XRD patterns. Results show that the absorbance is increased by 11% at A = 260 nm with the increase in the volumetric ratio. In contrast, the optical energy bandgap that is extrapolated from the Tauc’s plot is decreased with the increase in the volumetric ratio, and the 2:1 ratio shows the lowest energy in the UV region. In terms of the XRD investigation, the 2:1 volumetric ratio shows the highest intensity for the crystallinity peak at 36.6°. The fabricated photodetector with a different volumetric ratio of the active layer Alq3:NPD blend shows the best performance with the ratio 2:1.


1995 ◽  
Vol 34 (Part 1, No. 7B) ◽  
pp. 3884-3888 ◽  
Author(s):  
Takayoshi Hayashi ◽  
Tohru Maruno ◽  
Akira Yamashita ◽  
Stefan Fölsch ◽  
Hirohisa Kanbara ◽  
...  

2021 ◽  
Vol 2114 (1) ◽  
pp. 012060
Author(s):  
N. H. Mutesher

Abstract The objective of this research is to study the influence of deposition parameters such as gases mixing ratio O2/Ar on the structural and optical properties of the TiO2/SiO2 nanocomposite films synthesized using closed field unbalanced dc magnetron co-sputtering technique. The nanocomposite thin films were characterized using x-ray diffraction (XRD) to determine the phase structure, and Fourier transform infrared (FTIR) spectroscopy to investigate Si-O-Si, Ti-O and Si–O–Ti. functional groups. The UV-VIS. absorption spectra of the synthesized films reveal that the indirect energy band gap was found to be 2.75 eV. The mixing ratio of Oxygen and Argon (O2/Ar) gases has a pronounced controlling effect on the structural and optical properties of such nanocomposite.


2019 ◽  
Vol 16 (1) ◽  
pp. 196-211
Author(s):  
Magda Dawy Badry

Electrospun MWCNTs nanofibers (CNF1, CNF2 and CNF3) with different concentrations of MWCNTs (0.3, 1.5, 2 wt%), respectively, were deposited on Aluminum foil substrates.  Also,Zinc AcetatedihydrateZn(CH3COO)2.2H2O (ZNF) and MWCNTs/zinc acetate (CZNF)nanofiberswere deposited on Aluminum foil substratesand annealed in the presence of oxygen at 400 oC. The resultant fibers were characterized using X-ray differaction (XRD), scanning electron microscope with energy dispersive X-Ray spectrophotometry (SEM,EDX), Fourier transform infrared (FTIR). SEM,EDX and FTIR exhibited a total decomposition of the organic precursor after calcination and formation of zinc oxide (ZONF and CZONF). The mean fiber diameter was found to be increased with increasing MWCNTs concentration and ranged 490-767 nm. XRD patterns indicated that ZnO was corundum with the hexagonal wurtzite structure. The crystallite size of ZONF and CZONF were determined by shurrer equation to be26 and  29.7  nm, respectively. The optical analysis indicated that the percentage transmittance increased after calcination.The band gap for the electrospun fibers before and after calcination was calculated. CZONF nanofibers have elec­trical properties similar to those of semiconductors. The testedcompounds CNF2, CNF3, CZNF and CZONF exhibited different activities against the bacteriaand yeast pathogen Candidaalbicans. CZNF compound is the most active against the bacteria and yeast pathogen. So, these compounds can be used as food packaging.  


Cerâmica ◽  
2018 ◽  
Vol 64 (370) ◽  
pp. 190-196 ◽  
Author(s):  
V. A. Mu’izayanti ◽  
H. Sutrisno

Abstract The AgCl-sensitized TiO2 (TiO2@AgCl) has been prepared from the precursor of TiO2-rutile type which on its surface adsorb chloride anion (Cl-) and various amounts of silver using AgNO3 as starting material: AgNO3/(AgNO3+TiO2) mass ratio of 0.00, 1.14, 3.25, 6.38 and 10.32%. Reflux under alkaline condition was the employed technique. All samples were characterized by X-ray diffraction (XRD) and diffuse reflectance UV-vis spectroscopy. The sample without the addition of AgNO3 was analyzed by scanning electron microscope and surface area analyzer. The morphology of the sample showed a distribution of microspheres of approximately 0.5 to 1.0 µm and the specific surface area was 68 m2/g. XRD patterns indicated that the sample without the addition of AgNO3 contained two types of TiO2: rutile (major) and anatase (minor), whereas the samples with the addition of AgNO3 consisted of one phase of AgCl and two types of TiO2: rutile and anatase. The bandgaps of the samples were in the range of 2.97 to 3.24 eV, which were very close to the bandgap of intrinsic TiO2 powder. The presence of 0.8, 2.6 and 4.4 wt% of AgCl in each sample resulted in an additional bandgap in visible light region of 1.90, 1.94 and 2.26 eV, respectively, whereas the presence of 9.4 wt% of AgCl in the sample resulted in two bandgaps in visible light region of 1.98 and 1.88 eV.


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