scholarly journals Characteristics Study of Nanostructured CdO Prepared by Spray Pyrolysis

Author(s):  
Raid A. Ismail ◽  
Sa’ad Ghafori ◽  
Rafal S. Sichat

In this paper, nanostructured cadmium oxide films were prepared by chemical spray pyrolysis technique.The structural, morphological and optical characteristics of synthesized films are investigated as function of concentration .AFM results revealed that the root mean square of surface roughness is increased with cadmium concentration. XRD investigation confirmed that the films are polycrystalline with cubic structure. SEM study displayed that the synthesized films have particle size in the range of 25-100nm depending on cadmium ion concentration. The optical properties revealed the films have maximum average optical transmittance of 78% for film sprayed with 0.1 M. The optical band gap of the CdO film prepared with 0.25 M was 2.65eV. The optical band gap increased as the film molarity.

2018 ◽  
Vol 4 (5) ◽  
pp. 542-545 ◽  
Author(s):  
R. Shabu ◽  
A. Moses Ezhil Raj

As major attention has been paid to transition metal oxide semiconductor suitable for solar cell, photo detector and gas sensor, present study embark on the structural, optical and electrical characterization of Ag doped CuO thin films prepared using chemical spray pyrolysis technique at the constant substrate temperature of 350 �C. For Ag doping, various concentrations of silver acetate (0.5-3.0 wt.%) was used in the sprayed precursor solution. Confirmed monoclinic lattice shows the tenorite phase formation of CuO in the pure and Ag doped films. The optical band gap of the films was in the range of 2.4 -3.4 eV. A minimum resistivity of 0.0017x103 ohmcm was achieved in the 0.5 wt.% Ag doped film, and its optical band gap was 2.74 eV.


2021 ◽  
Vol 3 (7) ◽  
Author(s):  
A. Krishnamoorthy ◽  
P. Sakthivel ◽  
I. Devadoss ◽  
V. M. Anitha Rajathi

AbstractIn this work, the Cd0.9-xZn0.1BixS QDs with different compositions of Bi3+ ions (0 ≤ x ≤ 0.05) were synthesized using a facile chemical route. The prepared QDs were characterized for analyzing the structural, morphological, elemental, optical, band gap, photoluminescence and electrochemical properties. XRD results confirmed that the Cd0.9-xZn0.1BixS QDs have a cubic structure. The mean crystallite size was increased from ~ 2 to ~ 5 nm for the increase of Bi3+ ions concentration. The optical transmittance behavior was decreased with increasing Bi3+ ions. The scanning electron microscope images showed that the prepared QDs possessed agglomerated morphology and the EDAX confirmed the presence of doped elements as per stoichiometry ratio. The optical band gap was slightly blue-shifted for initial substitution (Bi3+  = 1%) of Bi3+ ions and red-shifted for further increase of Bi3+ compositions. The optical band gap was ranged between 3.76 and 4.0 eV. High intense red emission was received for Bi3+ (1%) doped Zn:CdS QDs. The red emission peaks were shifted to a higher wavelength side due to the addition of Bi3+ ions. The PL emission on UV-region was raised for Bi3+ (1%) and it was diminished. Further, a violet (422 nm) and blue (460 nm) emission were received for Bi3+ ions doping. The cyclic voltammetry analysis showed that Bi3+ (0%) possessed better electrical properties than other compositions of Bi3+ ions.


2019 ◽  
Vol 27 (04) ◽  
pp. 1950138
Author(s):  
FATMA MEYDANERİ TEZEL ◽  
İ. AFŞIN KARİPER

Undoped and silver, lithium and cobalt-doped ZnO thin films have been successfully deposited on glass by chemical bath deposition (CBD). The reaction temperature was 50∘C and the films were annealed at 400∘C for 4[Formula: see text]h in a high temperature furnace. UV/VIS spectrum was used to determine optical transmittance, optical band gap ([Formula: see text] and absorbance values of Ag:ZnO, Co:ZnO, Li:ZnO and undoped ZnO thin films. Optical band gap ([Formula: see text] and absorbance values of undoped ZnO, Ag:ZnO, Co:ZnO and Li:ZnO thin films were found as 0.0158, 0.0064, 0.2638, 0.0956 and 3.24, 3.13, 3.27, 2.96 eV, respectively. Extinction coefficients and refraction indexes of the films were found to be 0.0096, 0.0038, 0.0068, 0.019 (extinction coefficient) and 1.26, 1.14, 1.66, 2.33 (refraction index), respectively. X-ray patterns of undoped ZnO, Ag:ZnO, Co:ZnO and Li:ZnO thin films were confirmed as amorphous.


1970 ◽  
Vol 32 (1) ◽  
pp. 97-105 ◽  
Author(s):  
MM Islam ◽  
MR Islam ◽  
J Podder

Cadmium oxide (CdO) thin films have been deposited by a locally developed spray pyrolysis method onto glass substrate at 473K. The optical and electrical properties of the as-deposited and annealed films are studied in details. The surface morphology of the samples was studied by scanning electron microscopy (SEM). The SEM micrograph of as-deposited film shows uniform deposition over the substrate well. The optical absorption coefficient (α) of the CdO films was determined from transmittance spectra in the range of wavelength 450 - 650nm. For different thicknesses (130nm ~ 380nm) of as-deposited films, the direct band gap is found in the range of 2.40 ~2.51 eV and indirect band gap in the range of 1.97 ~ 2.20 eV. Resistivity (ρ) of CdO thin film was measured in the temperature range of 303 to 553K. The resistivity of the films of different thickness initially increases with increase in temperature and reaches a maximum at 430K and then decreases with further increase of temperature. The resistivity of the film exhibits metallic behaviour up to 430 K and above that the film behaves like a semiconductor. Activation energy (ΔE) in the semiconductor region is found in the range from 0.049 to 0.075 eV for films of thickness ranging from 160 - 285 nm. Keywords: Spray pyrolysis, CdO, Resistivity, Optical band gap, Activation energy doi: 10.3329/jbas.v32i1.2447 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 97-105, 2008


2016 ◽  
Vol 12 (27) ◽  
pp. 263 ◽  
Author(s):  
Md. Mahafuzur Rahaman ◽  
Kazi Md. Amjad Hussain ◽  
Mehnaz Sharmin ◽  
Chitra Das ◽  
Shamima Choudhury

Indium doped Tin oxide (SnO2: In) thin films of various thicknesses (200-600 nm) with fixed 2% indium (In) concentration were prepared by thermal evaporation method onto glass substrates under high vacuum (10-6 Torr). As deposited films were vacuum annealed at 200o C for 60 minutes. The structure, optical, electrical and morphology properties of SnO2: In thin films were investigated as a function of film thickness. The XRD analysis revealed that films were polycrystalline in nature with a tetragonal structure having (110) plane as the preferred orientation. The average crystalline size increased from 34.8 to 51.25 nm with increase of film thicknesses. The surface morphology of the doped films was obtained by Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM). Optical transmittance was obtained from a double beam UV-Vis- NIR spectrophotometer. Maximum transmittance varied from 65-76% in the visible range of the spectrum. Optical band gap (Eg) varied between 2.89 and 3.20 eV. The resistivity of SnO2: In thin films was as high as 105 Ω-cm. Activation energy of the films were found to be 0.18 to 0.47 eV for 300-600 nm film thicknesses. Due to high optical band gap and high electrical resistivity, these nanostructured films can be used in optoelectronic devices especially as opto-insulator.


2017 ◽  
Vol 68 (7) ◽  
pp. 10-16 ◽  
Author(s):  
Jarmila Müllerová ◽  
Pavol Šutta ◽  
Rostislav Medlín ◽  
Marie Netrvalová ◽  
Petr Novák

AbstractIn this paper we report results from optical transmittance spectroscopy complemented with data on structure from XRD measurements to determine optical properties of a series of ZnTiO3perovskite thin films deposited on glass by reactive magnetron co-sputtering. The members of the series differ by the titanium content that was revealed as an origin of the changes not only in structure but also in dispersive optical properties. Low porosity has been discovered and calculated using the Bruggeman effective medium approximation. An apparent blue-shift of the optical band gap energies with increasing titanium content was observed. The observed band gap engineering is a good prospective foregoptoelectronic and photocatalytic applications of ZnTiO3.


1988 ◽  
Vol 106 (2) ◽  
pp. K143-K146 ◽  
Author(s):  
W. A. Murad ◽  
S. M. Al-Shamari ◽  
F. H. Al-Khateeb ◽  
R. H. Misho

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