scholarly journals A study of hydrothermally grown ZnO nanorod-based metal-semiconductor-metal UV detectors on glass substrates

2017 ◽  
Vol 7 ◽  
pp. 184798041770214 ◽  
Author(s):  
Shaivalini Singh ◽  
Yogesh Kumar ◽  
Hemant Kumar ◽  
Sumit Vyas ◽  
Chinnamuthan Periasamy ◽  
...  

This study reports hydrothermally grown zinc oxide nanorod-based metal-semiconductor-metal ultraviolet detectors with palladium metal as the electrodes. The zinc oxide nanorods were deposited on glass substrates in two steps, seed layer deposition and growth of nanorods. The structural and optical properties of nanorods were examined using scanning electron microscopy and ultraviolet–vis spectroscopy, respectively. The scanning electron microscopy image showed that the growth of nanorods was uniform, and the ultraviolet–vis results indicate that the bandgap of zinc oxide nanorods was 3.23 eV. For metal-semiconductor-metal devices, interdigited metal electrodes with equal interelectrode spacing and a width of 0.3 mm were deposited above the zinc oxide nanorod thin films with a shadow mask using a thermal evaporation system. The current–voltage characteristics of the metal-semiconductor-metal detector were investigated and it showed a contrast ratio of approximately 2.10 and responsivity of approximately 0.199 A/W at 1.8 V. These results are expected to be beneficial to fabricating cheap and practical ultraviolet detection applications.

2020 ◽  
Vol 7 (4) ◽  
pp. 154-158
Author(s):  
E. V. Maraeva ◽  
N. V. Permiakov ◽  
Y. Y. Kedruk ◽  
L. V. Gritsenko ◽  
Kh. A. Abdullin

The work is devoted to the creation of a virtual device (computer program) for processing the results of sorption analysis of nanomaterials, including for estimating the size of nanoparticles based on the specific surface area. The obtained evaluation results were compared with the scanning electron microscopy data. Photocatalytically active zinc oxide samples were chosen as the object of the study.


2013 ◽  
Vol 667 ◽  
pp. 375-379 ◽  
Author(s):  
M. Awalludin ◽  
Mohamad Hafiz Mamat ◽  
Mohd Zainizan Sahdan ◽  
Z. Mohamad ◽  
Mohamad Rusop

This paper focus on zinc oxide (ZnO) nanorods prepared using sol-gel immersion method immersed at different time. Immersion times have been varied 1~24 hr and the characteristics of each sample have been observed. The effects of immersion time on ZnO nanorods thin films have been studied in surface morphology and structural properties using Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD), respectively.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1136 ◽  
Author(s):  
Siti Shafura A Karim ◽  
Yuzuru Takamura ◽  
Phan Trong Tue ◽  
Nguyen Thanh Tung ◽  
Jamal Kazmi ◽  
...  

Highly ordered vertically grown zinc oxide nanorods (ZnO NRs) were synthesized on ZnO-coated SiO2/Si substrate using zinc acetylacetonate hydrate as a precursor via a simple hydrothermal method at 85 °C. We used 0.05 M of ZnO solution to facilitate the growth of ZnO NRs and the immersion time was varied from 0.5 to 4 h. The atomic force microscopy revealed the surface roughness of ZnO seed layer used to grow the ZnO NRs. The morphology of vertically grown ZnO NRs was observed by field emission scanning electron microscopy. X-ray diffraction examination and transmission electron microscopy confirmed that the structure of highly ordered ZnO NRs was crystalline with a strong (002) peak corresponded to ZnO hexagonal wurtzite structure. The growth of highly ordered ZnO NRs was favorable due to the continuous supply of Zn2+ ions and chelating agents properties obtained from the acetylacetonate-derived precursor during the synthesis. Two-point probe current–voltage measurement and UV–vis spectroscopy of the ZnO NRs indicated a resistivity and optical bandgap value of 0.44 Ω.cm and 3.35 eV, respectively. The photoluminescence spectrum showed a broad peak centered at 623 nm in the visible region corresponded to the oxygen vacancies from the ZnO NRs. This study demonstrates that acetylacetonate-derived precursors can be used for the production of ZnO NRs-based devices with a potential application in biosensors.


Author(s):  
S C Joshi ◽  
Utkarsh Kaushik ◽  
Aproova Upadhyaya ◽  
Priyanka Sharma

ABSTRACTObjective: The synthesis of nanoparticles from biological processes is evolving a new era of research interests in nanotechnology. Silver nanoparticlesare usually synthesized by chemicals and physical method, which are quite toxic and flammable in nature. This study deals with an environmentfriendly biosynthesis process of antibacterial silver nanoparticles using Momordica charantia fruit.Methods: AgNO3 (5 mM) was allowed to react with fruit extract of M. charantia. Biosynthesis of AgNPs was optimized by changing temperature,pH, and solvent. The silver nanoparticles so formed were characterized using ultraviolet-visible (UV-VIS) spectroscopy, Fourier transform infraredspectroscopy (FTIR), dynamic light scattering (DLS), atomic force microscope (AFM), and scanning electron microscopy (SEM).Results: UV-VIS spectra show absorption peak between 420 and 430 nm. The FTIR analysis showed the alcoholic, lactam, and nitro group presentin the plant extract, which were responsible for the reduction in AgNPs. The SEM images showed the size distribution of the nanoparticles and theaverage size was found to be 50-100 nm. By DLS analysis and AFM analysis, average sizes of the silver nanoparticles were of 150 nm. The results ofthese analyses confirmed the formation of silver nanoparticles. Silver nanoparticles were tested against Bacillus cereus and Staphylococcus epidermidisstrains using disc diffusion method and were found to be effective.Conclusion: Silver nanoparticles so synthesized in this study using fruit extract of M. charantia are simple, easy, and effective technique of nanoparticlesproduction.Keywords: Silver nanoparticles, Momordica charantia, Optimization, Antibacterial, Atomic force microscope, Scanning electron microscopy.


2000 ◽  
Vol 6 (S2) ◽  
pp. 454-455
Author(s):  
Ram Kishore ◽  
Venkatram Korapati ◽  
W.D. Brown ◽  
H.A. Naseem

CdTe/CdS thin film solar cells are being investigated extensively these days by many workers as an option for low cost photovoltaic applications . In order to achieve high efficiency solar cell it is important that the CdS film should have minimum possible structural defects and reasonably large grain size. The CdS films for CdTe/ CdS solar cell structure are mostly grown on glass substrates by chemical bath deposition (CBD). Although adherent, transparent and conformal films with index of refraction close to single crystal CdS can be grown by CBD, impurity inclusions and micropinholes are a problem there in. Very little work has been carried out to grow CdS films by thermal evaporation in vacuum. In the present work we have grown pure and CdCl2 doped CdS films on glass substrates by thermal evaporation and carried out microstructural investigations of these films using scanning electron microscopy.Corning 7059 glass of 25.4 x 25.4 x 1.2 mm size were used as substrates for the deposition of CdS as well as CdCl2 doped CdS films.


2015 ◽  
Vol 1109 ◽  
pp. 568-571
Author(s):  
Shafura Karim ◽  
Uzer Mohd Noor ◽  
M.H. Mamat ◽  
Shuhaimi Abu Bakar ◽  
Salman A.H. Alrokayan ◽  
...  

Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc acetate dehydrate as a starting material by sol-gel immersion method. The doping concentrations were varied at 0 at.%, 1.0 at.%, 2.0 at.% and 3.0 at.%. The synthesized samples were characterized by Field Emission Scanning Electron Microscopy (FESEM).


Clay Minerals ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Z. Klika ◽  
P. Pustková ◽  
M. Dudová ◽  
P. Čapková ◽  
Ch. Kliková ◽  
...  

AbstractThe adsorption of methylene blue (MB) on montmorillonite from acid solutions has not yet been studied in detail. In this paper the adsorption of this dye on Ca/SAz montmorillonite from 0.32, 0.80 and 1.60 M HCl solutions at ambient temperature and after 2 hours leaching was carefully studied and evaluated. Under the above conditions the MB/SAz intercalates formed are practically insoluble. In contrast to the adsorption of methylene blue on montmorillonite from aqueous solutions, the adsorption from acid solutions consists of two adsorption waves. The intercalated samples from the first and second waves were studied using X-ray powder diffraction (XRD), FTIR, Vis spectroscopy, and scanning electron microscopy (SEM) equipped with a microprobe system. The adsorption of MB in the first wave is attributed to ion exchange of the dye cationic species (MB+, MB22+, H-aggregates, MBH2+ and H+) for the original interlayer cations of montmorillonite. The percentages of MBH2+ and H+ based on total adsorbed MB were estimated for varying HCl concentrations. The second adsorption wave is linked to the precipitation of MB species on the outer MB/SAz surface.


2017 ◽  
Vol 2 (2) ◽  
pp. 148
Author(s):  
Sheilla Rully Anggita ◽  
Heri Susanto

<div style="text-align: justify;"><div>Various concentration of silver (Ag) dopant on ZnO (ZnO:Ag) 2-8 mol% with solgel method were deposited on glass substrates that has been heated to a temperature of 250°C for 1h using a thermal spray coating technique and then annealed on 400C for 1h. The obtained samples were characterized by Scanning Electron Microscopy (SEM). The effect of various Ag dopant on ZnO on the microstructure are investigated. The results showed that the microstructure of ZnO:Ag are the surface of ZnO make ganglia phase with Ag grains covered the surface. The addition concentration of Ag promotes the growth of ganglia phase and grain size. The surface of ZnO:Ag ≤4 mol% the growth grain Ag is more dominant than the growth of ZnO. The dopant Ag with a concentration of 4-8mol% ganglia structure begin to form with the presence of grains. Obtained the surface of ZnO:Ag 4 mol% begins to growth ganglia phase with the largest graindiameter is 304.8 nm. ©2016 JNSMR UIN Walisongo. All rights reserved.</div></div>


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