scholarly journals Growth, Structural and Optical Characterization of ZnO Nanotubes on Disposable-Flexible Paper Substrates by Low-Temperature Chemical Method

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. Y. Soomro ◽  
I. Hussain ◽  
N. Bano ◽  
Jun Lu ◽  
L. Hultman ◽  
...  

We report the synthesis of vertically aligned ZnO nanotubes (NTs) on paper substrates by low-temperature hydrothermal method. The growth of ZnO NTs on the paper substrate is discussed; further, the structural and optical properties are investigated by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and cathodoluminescence (CL), and it was found that the ZnO NTs on paper substrate fulfill the structural and optical properties of ZnO NTs grown on other conventional substrates. This will be more beneficial in future usage of ZnO NTs in different fields and applications. Particularly, this approach opens the ways in research and development for high volume manufacturing of low-cost, flexible optoelectronics devices on disposable paper substrates and can be used in the future miniaturization trends.

Author(s):  
T. S. Cheng ◽  
C. T. Foxon ◽  
N. J Jeffs ◽  
O. H. Hughes ◽  
B. G. Ren ◽  
...  

Films of GaN have been grown using a modified MBE method in which the active nitrogen is supplied from an RF activated plasma source. Wurtzite films grown on (0 0 1) oriented GaAs substrates show highly defective, ordered polycrystalline growth with a columnar structure; the (0 0 0 1) planes of the layers being parallel to the (0 0 1) planes of the GaAs substrate. Films grown using a coincident As flux, however, have a single crystal zinc-blende growth mode. They have better structural and optical properties. To improve the properties of the wurtzite films we have studied the growth of such films on (1 1 1)A and (1 1 1)B oriented GaAs substrates. The improved structural properties of such films, assessed using x-ray and TEM methods, correlate with better low temperature PL performance.


2015 ◽  
Vol 47 (2) ◽  
pp. 187-194 ◽  
Author(s):  
M. Novakovic ◽  
M. Popovic ◽  
N. Bibic

The present study deals with CrN films irradiated at room temperature (RT) with 200 keV Ar+ ions. The CrN layers were deposited by d.c. reactive sputtering on Si (100) wafers, at nitrogen partial pressure of 5?10-4 mbar, to a total thickness of 280 nm. The substrates were held at 150?C during deposition. After deposition the CrN layers were irradiated with 200 keV Ar+ ions to the fluences of 5?1015 - 2?1016 ions/cm2. Structural characterization was performed with Rutherford backscattering spectroscopy (RBS), cross-sectional transmission electron microscopy (XTEM) and X-ray diffraction (XRD). Spectroscopic ellipsometry measurements were carried out in order to study optical properties of the samples. The irradiations caused the microstructrual changes in CrN layers, but no amorphization even at the highest argon fluence of 2?1016 ions/cm2. Observed changes in microstructure were correlated with the variation in optical parameters. It was found that both refractive index and extinction coefficient are strongly dependent on the defect concentration in CrN layers.


2002 ◽  
Vol 80 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Xuchuan Jiang ◽  
Yi Xie ◽  
Jun Lu ◽  
Liying Zhu ◽  
Wei He ◽  
...  

Submicrometer hollow CuS, CdS, and NiS spheres with diameters between 400 and 1300 nm were successfully prepared through an interface-mineralizing reaction in a NH3·H2O–CS2 solution at low temperature. Several techniques were applied to characterize the interesting self-assembled structures. The compositions of the prepared CuS, CdS, and NiS materials were confirmed by X-ray powder diffraction (XRD), the surface atomic ratios and the valence state of ions were examined by X-ray photoelectron energy spectroscopy (XPS), and the morphologies of products by transmission electron microscope (TEM). The optical properties, including absorption and emission, were recorded by UV–vis absorption and fluorescence spectroscopy, respectively. In this approach, ethylenediamine (en) was substituted by aqueous ammonia (NH3·H2O) to avoid violent reactions with carbon disulfide (CS2). The main advantage to this approach is that both ammonia and CS2 played multi-functional roles in the assembly of hollow-sphere structures. The reaction sources themselves (CS2) served as the reaction template and required no other templates to support it. The proposed interface-mineralizing mechanism is discussed, and the hollow-sphere structures obtained are envisioned to have applications in area of materials science.Key words: hollow-sphere structure, NH3·H2O–CS2, metal sulfides


2008 ◽  
Vol 8 (2) ◽  
pp. 572-576 ◽  
Author(s):  
P. Caldelas ◽  
A. G. Rolo ◽  
A. Chahboun ◽  
S. Foss ◽  
S. Levichev ◽  
...  

Ge nanocrystals (NCs) embedded in aluminum oxide were grown by RF-magnetron sputtering. Raman, high resolution transmission electron microscopy (HRTEM), selected area diffraction (SAD), and X-ray diffraction (XRD) techniques confirmed good cristallinity of the NCs from samples annealed at 800 °C. The average NC size was estimated to be around 7 nm. Photoluminescence (PL) measurements show an emission related to the NCs. The temperature dependence of the PL confirms the confinement phenomenon in the Ge NCs.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Damian C. Onwudiwe ◽  
Madalina Hrubaru ◽  
Eno E. Ebenso

The thermal decomposition of bis(N,N-diallyldithiocarbamato)Cd(II) in a “one-pot” synthesis in tri-n-octylphosphine oxide (TOPO) and hexadecylamine (HDA) afforded CdS (TOPO-CdS and HDA-CdS) of varying optical properties and morphologies. The influence of the ratio of the precursor concentration to the capping molecule, as a factor affecting the morphology and size of the nanoparticles, was investigated. The particles varied in shape from spheres to rods and show quantum size effects in their optical spectra with clear differences in the photoluminescence (PL) spectra. The PL spectrum of the HDA capped CdS nanoparticles has an emission maximum centred at 468, 472, and 484 nm for the precursor to HDA concentration ratio of 1 : 10, 1 : 15, and 1 : 20, respectively, while the TOPO capped nanoparticles show emission peaks at 483, 494, and 498 nm at the same concentration ratio. Powdered X-ray diffraction (p-XRD) shows the nanoparticles to be hexagonal. The crystallinity of the nanoparticles was evident from high resolution transmission electron microscopy (HRTEM) which gave well-defined images of particles with clear lattice fringes.


2016 ◽  
Vol 12 (3) ◽  
pp. 4394-4399
Author(s):  
Sura Ali Noaman ◽  
Rashid Owaid Kadhim ◽  
Saleem Azara Hussain

Tin Oxide and Indium doped Tin Oxide (SnO2:In) thin films were deposited on glass and Silicon  substrates  by  thermal evaporation technique.  X-ray diffraction pattern of  pure SnO2 and SnO2:In thin films annealed at 650oC and the results showed  that the structure have tetragonal phase with preferred orientation in (110) plane. AFM studies showed an inhibition of grain growth with increase in indium concentration. SEM studies of pure  SnO2 and  Indium doped tin oxide (SnO2:In) ) thin films showed that the films with regular distribution of particles and they have spherical shape.  Optical properties such as  Transmission , optical band-gap have been measured and calculated.


2015 ◽  
Vol 33 (4) ◽  
pp. 714-718 ◽  
Author(s):  
Neeraj K. Mishra ◽  
Chaitnaya Kumar ◽  
Amit Kumar ◽  
Manish Kumar ◽  
Pratibha Chaudhary ◽  
...  

AbstractA nanocomposite of 0.5SnO2–0.5Al2O3 has been synthesized using a sol-gel route. Structural and optical properties of the nanocomposite have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray diffraction spectroscopy confirm the phase purity and the particle size of the 0.5SnO2–0.5Al2O3 nanocomposite (13 to 15 nm). The scanning electron microscopy also confirms the porosity in the sample, useful in sensing applications. The FT-IR analysis confirms the presence of physical interaction between SnO2 and Al2O3 due to the slight shifting and broadening of characteristic bands. The UV-Vis analysis confirms the semiconducting nature because of direct transition of electrons into the 0.5SnO2–0.5Al2O3 nanocomposites.


2014 ◽  
Vol 989-994 ◽  
pp. 656-659
Author(s):  
Ping Cao ◽  
Yue Bai

Al co-doped ZnCoO thin film has been prepared by a sol-gel method. The structural and optical properties of the sample were investigated. X-ray diffraction and UV absorption spectroscopy analyses indicate that Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Beomjin Kim ◽  
Woo Chang Song ◽  
Sun Young Park ◽  
Geuntae Park

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics.


2021 ◽  
Vol 19 (11) ◽  
pp. 66-71
Author(s):  
Maithm A. Obaid ◽  
Suha A Fadaam ◽  
Osama S. Hashim

The aim of this study is to prepare gold nanoparticles by a simple chemical method at a temperature of 70°C. The solution was dried on glass basest by Casting method, the rate of five drops per sample At a temperature 100 C. Then the structural and optical properties have been confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Transmission Electron microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and spectrum.


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