scholarly journals Structural, optical and electrical characterization of CBD synthesized CdO thin films: influence of deposition time

2017 ◽  
Vol 35 (3) ◽  
pp. 470-478 ◽  
Author(s):  
M.R. Das ◽  
A. Mukherjee ◽  
P. Mitra
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Deposition Time ◽  
Optical Band Gap ◽  
Average Particle Size ◽  
Cadmium Oxide ◽  
Cadmium Acetate ◽  
Localized States ◽  
Average Particle ◽  
Cdo Thin Films

AbstractCadmium oxide (CdO) thin films were grown on glass substrates by chemical bath deposition (CBD) method for different deposition times using cadmium acetate as cationic precursor. The structural and optical characterization was carried out using XRD, TEM, and UV-Vis spectrophotometer measurements. Structural analyses with XRD confirmed cubic structure of the CdO. Average particle size estimated from Rietveld refinement method of XRD pattern corresponded well with TEM measurement. The optical band gap varied between 2.35 eV to 2.48 eV with deposition time and an increase in optical band gap with decreasing film thickness was observed. The AC electrical conduction behavior of the CdO film was investigated as a function of temperature as well as frequency. The conductivity measurements indicated localized conduction and hopping of carriers between localized states. The value of real part of dielectric constant was found to decrease with frequency and increase with temperature. The Nyquist plots at different temperatures showed the existence of both grains and grain boundaries contributing to conduction mechanism.

scholarly journals Optical properties of CdO thin films

2010 ◽  
Vol 7 (1) ◽  
pp. 10-13
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Glass Substrate ◽  
Optical Band Gap ◽  
Spray Pyrolysis Technique ◽  
Cadmium Oxide ◽  
Localized States ◽  
Different Temperatures ◽  
Cdo Thin Films

Cadmium Oxide thin films were deposited on glass substrate by spray pyrolysis technique at different temperatures (300,350,400, 500)oC. The optical properties of the films were studied in this work. The optical band-gap was determined from absorption spectra, it was found that the optical band-gap was within the range of (2.5-2.56)eV also width of localized states and another optical properties.

scholarly journals Optical and Electrical Characteristics of CdO thin films deposited by Spray Pyrolysis Method

1970 ◽  
Vol 32 (1) ◽  
pp. 97-105 ◽  
Author(s):  
MM Islam ◽  
MR Islam ◽  
J Podder
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Band Gap ◽  
Spray Pyrolysis ◽  
Cadmium Oxide ◽  
Optical Absorption Coefficient ◽  
Spray Pyrolysis Method ◽  
Pyrolysis Method ◽  
Sem Micrograph ◽  
Cdo Thin Films

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

scholarly journals Conductivity and Density of States of New Polyphenylquinoline

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 934 ◽  
Author(s):  
Shamil R. Saitov ◽  
Dmitriy V. Amasev ◽  
Alexey R. Tameev ◽  
Vladimir V. Malov ◽  
Marine G. Tedoradze ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Band Gap ◽  
Density Of States ◽  
Optical Band Gap ◽  
Dark Conductivity ◽  
Localized States ◽  
Energy Distance ◽  
Temperature Dependences

Electrical, photoelectrical, and optical properties of thin films of a new heat-resistant polyphenylquinoline synthesized using facile methods were investigated. An analysis of the obtained temperature dependences of the dark conductivity and photoconductivity indicates the hopping mechanism of conductivity over localized states arranging at the energy distance of 0.8 eV from the Fermi level located inside the band gap of the investigated material. The optical band gap of the studied material was estimated from an analysis of the spectral dependences of the photoconductivity and absorption coefficient before (1.8–1.9 eV) and after (2.0–2.2 eV) annealing at temperatures exceeding 100 °C. The Gaussian character of the distribution of the localized states of density inside the band gap near the edges of the bands was established. A mechanism of changes in the optical band gap of the investigating polymer under its annealing is proposed.

Theoretical analysis on the sensitivity to partial pressure of oxygen of the band gap shift in CdO thin films

2016 ◽  
Vol 30 (31) ◽  
pp. 1650371 ◽  
Author(s):  
M. A. Grado-Caffaro ◽  
M. Grado-Caffaro
Keyword(s):  
Thin Films ◽  
Partial Pressure ◽  
Band Gap ◽  
Cadmium Oxide ◽  
Visible Region ◽  
Visible Range ◽  
Partial Pressure Of Oxygen ◽  
Sensitivity Functions ◽  
Suitable Parameter ◽  
Cdo Thin Films

With the aim of providing an analytical approach (not accurate numerical results), for the first time, the sensitivity to the partial pressure of oxygen of the shift in the energy band gap experienced by cadmium-oxide thin films is evaluated for the visible region by introducing a suitable parameter. The sensitivity to the above pressure of the spatial carrier density is determined and compared with the sensitivity relative to the band gap shift. The gradient of the CdO carrier concentration as a function of the partial pressure of oxygen appears in the expressions for the two above sensitivity functions but the goal of this paper is not computing numerically this gradient so only qualitative estimations are done. In relation to the above results, the kinetics relative to the formation of CdO thin films are investigated. In addition, the sensitivity to the pressure in question of the corresponding optical-absorption shift in the visible range is calculated.

Role of Al in engineering the optical band gap and PL emission intensity properties of CdO thin films grown by SILAR method

2022 ◽  
Vol 123 ◽  
pp. 111921
Author(s):  
Harun Güney ◽  
Demet İskenderoğlu ◽  
Muhammed Emin Güldüren ◽  
Sibel Morkoç Karadeniz
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Emission Intensity ◽  
Optical Band Gap ◽  
Silar Method ◽  
Pl Emission ◽  
Cdo Thin Films

Optical band gap controlling of nanostructure Mn doped CdO thin films prepared by sol–gel spin coating method

Optik ◽  
2015 ◽  
Vol 126 (5) ◽  
pp. 575-577 ◽  
Author(s):  
Zayed A. Alahmed ◽  
H.A. Albrithen ◽  
Ahmed A. Al-Ghamdi ◽  
F. Yakuphanoglu
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Spin Coating Method ◽  
Coating Method ◽  
Cdo Thin Films ◽  
Mn Doped

Preparation and characterization of nano sized pure ZnTe and antimony doped ZnTe nano thin films by spray pyrolysis technique

2018 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
N Senthil Kumar ◽  
K Mohanraj ◽  
R Thangarasu ◽  
B Mohanbabu ◽  
B Babu
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Optical Band Gap ◽  
Spray Pyrolysis Technique ◽  
Average Particle Size ◽  
Good Evidence ◽  
Average Particle ◽  
Antimony Doping ◽  
Good Agreement

Antimony doped ZnTe thin films developed by spray pyrolysis technique. The deposited thin films are characterized by X-ra diffraction (XRD), scanning electron microscope (SEM), energy dispersive electron microscopy (EDS) and ulra-violet visible spectroscopy (UV-Vis). XRD studies indicate that antimony doping in host result a crystallinity change. The average particle size calculated from XRD values is in good agreement with the SEM results. EDS spectrum is a good evidence of confirm the formation of antimony doped ZnTe. An optical band gap calculated value varying from 2.3 eV to1.9 eV. The extinction coefficient increases depending on the temperature 300 ̊ C, 350 ̊ C and 400 ̊ C.

QUANTUM SIZE EFFECT ON THE OPTICAL PROPERTIES OF RF MAGNETRON SPUTTERED NANOCRYSTALLINE CADMIUM OXIDE THIN FILMS

2011 ◽  
Vol 10 (04n05) ◽  
pp. 713-716 ◽  
Author(s):  
B. SAHA ◽  
R. THAPA ◽  
N. S. DAS ◽  
K. K. CHATTOPADHYAY
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Quantum Confinement Effect ◽  
Cadmium Oxide ◽  
Quantum Size ◽  
Device Applications ◽  
Cdo Films ◽  
Different Thickness

CdO thin film with different thickness and different particle size are prepared through radio frequency magnetron sputtering technique. Quantum confinement effect causes the significant changes in their optical properties showing significant changes in the optical band gap. The CdO films are very highly conducting and transparent. Transparent and conducting thin films of CdO with effectively increased optical band gap are very useful for different device applications like solar cell, optoelectronic devices.

scholarly journals Nanostructured CdO Thin Films for LPG and CO2 Gas Sensor Prepared by Spray Pyrolisis Technique

2014 ◽  
Vol 37 ◽  
pp. 31-46 ◽  
Author(s):  
R.H. Bari ◽  
S.B. Patil
Keyword(s):  
Thin Films ◽  
Deposition Time ◽  
Gas Sensing ◽  
Spray Deposition ◽  
Cadmium Acetate ◽  
Xrd Analysis ◽  
Glass Substrates ◽  
Response And Recovery ◽  
Cdo Thin Films ◽  
Gas Response

Nanostructured CdO thin films were deposited by spray pyrolysis techniques at different spray deposition time on glass substrates. Nanostructured CdO thin films was prepared using 0.05 M of cadmium acetate dehydrate (CH3COO) 2Cd·2H2O) was dissolved in the deionised water. These thin films were annealing in air at temperatures 500 °C for 60 min. The thickness of the films, crystallite and grain size were observed to increase with the increase in spray deposition time. As prepared thin films were characterized using XRD, FE-SEM and EDAX. The XRD analysis shows that CdO films were cubic structured. The electrical and gas sensing properties of these films were investigated. Prepared nanostructure CdO thin films show LPG (S = 1600) and CO2 (S = 435) gas response at different operating temperature. Gas response, selectivity, response and recovery time of the sensor were measured and presented.

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