Effect of Precursor Solvents on the Optical Properties of Copper Oxide Thin Films Deposited Using Spray Pyrolysis for Optoelectronic Applications

Fasasi, A.Y.

doi:10.11648/j.ajmsp.20180302.12

Cited by 18 publications

(8 citation statements)

References 30 publications

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“…These increasing values of both charge carriers/m* and the ε ∞ can be considered indicators of increasing free charge carriers that vigorously participate in the polarization process. In the current study, the values that were estimated for the localized density of states ( N/m* ) are in good accordance with those reported in the literature using Equation (7) [ 87 , 88 ].…”

Section: Resultssupporting

confidence: 91%

“…The optical characteristics of solids can be preliminarily estimated from the CDF, which can be linked to the detectable optical quantities using straightforward equations [ 88 ]. Previous studies have emphasized the existence of a strong relationship between the optical dielectric functions ( ε r and ε i ) and the density of localized electronic states within the forbidden gap of the composite films [ 72 , 98 , 99 ].…”

Section: Resultsmentioning

confidence: 99%

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Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

et al. 2021

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In this work, a green approach was implemented to prepare polymer composites using polyvinyl alcohol polymer and the extract of black tea leaves (polyphenols) in a complex form with Co2+ ions. A range of techniques was used to characterize the Co2+ complex and polymer composite, such as Ultraviolet–visible (UV-Visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The optical parameters of absorption edge, refractive index (n), dielectric properties including real and imaginary parts (εr, and εi) were also investigated. The FRIR and XRD spectra were used to examine the compatibility between the PVA polymer and Co2+-polyphenol complex. The extent of interaction was evidenced from the shifts and change in the intensity of the peaks. The relatively wide amorphous phase in PVA polymer increased upon insertion of the Co2+-polyphenol complex. The amorphous character of the Co2+ complex was emphasized with the appearance of a hump in the XRD pattern. From UV-Visible spectroscopy, the optical properties, such as absorption edge, refractive index (n), (εr), (εi), and bandgap energy (Eg) of parent PVA and composite films were specified. The Eg of PVA was lowered from 5.8 to 1.82 eV upon addition of 45 mL of Co2+-polyphenol complex. The N/m* was calculated from the optical dielectric function. Ultimately, various types of electronic transitions within the polymer composites were specified using Tauc’s method. The direct bandgap (DBG) treatment of polymer composites with a developed amorphous phase is fundamental for commercialization in optoelectronic devices.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

et al. 2021

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“…The effect of the number of passes on Cu-doped Fe 2 O 3 is depicted in Figure 3a where it can be seen that the increase in the number of passes led to a decrease in transmittance. This trend had been observed in CuO film deposited by spray pyrolysis [71]. Two distinct regions can be observed on the spectra with the line of demarcation around 648 nm which corresponds to 1.92 eV.…”

Section: Transmission Analysessupporting

confidence: 64%

Optical, Dielectric and Optoelectronic Properties of Spray Deposited Cu-doped Fe2O3 Thin Films

Fasasi,

Ajenifuja,

Osagie

et al. 2023

J. Nig. Soc. Phys. Sci.

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Copper-doped hematite thin films were prepared by spray pyrolysis technique using a mixture of ethanol and distilled water precursors. Visual observations showed that aqua precursor produced films of less integrity compared with ethanol that produced thin, uniform and transparent yellowish-brown films that adhered well to the substrate. Composition and thickness measurements determined by RBS revealed that ethanol precursor produced thinner films of 94.45 and 51.77 nm while aqua precursor produced films of 1,370 and 1,120 nm for undoped and Cu-doped Fe2O3 respectively. This is an indication that ethanol solutions produced nano-thick films of high integrity. The composition revealed that only the Cu-doped Fe2O3 deposited by ethanol solution gave composition close to stoichiometric Fe2O3 while the others gave non-stoichiometric Fe(OH)3 . Optical characterization carried out using UV-visible spectrophotometer in transmittance mode indicated that the film thickness was directly proportional to the number of passes which is inversely proportional to the transmittance. Three bandgap determination methods namely; Tauc, Absorption Fitting Spectrum (AFS) and Davis-Mott were employed with the result that Tauc and AFS gave close direct and indirect bandgap energies (Eg) of 3.44 and 1.98 for AFS and 3.43 and 2.32 eV for Tauc respectively. The Urbach tail energy determined was 1,100 meV which is an indication of a broad onset of absorption. The steepness parameter (?) was found to be 7.83 while the electron-phonon (Eph ) coupling energy was found to be 0.85 eV. It was also observed that the refractive index (n) was about 15 times greater than the extinction coefficient (k). In the study of the dispersion parameters using single oscillator and Sellmier models, the values of the single oscillator energy (Eosc ), dispersion energy (Ed), zero frequency dielectric constant, zero frequency refractive index, the average oscillator strength (So), the average oscillator parameter and the dispersion parameters were determined. All the values of the parameters estimated are of the same order of magnitude with other semiconducting materials. The study showed that Cu-doped Fe2O3 could be employed as dielectric material as well as in optoelectronic devices.

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“…Furthermore, the dispersion of the imaginary part of the dielectric function ε2() is used to estimate the relaxation time (τ), optical mobility (opt) and optical resistivity (opt) in the framework of the Drude free electron model [23,34]…”

Section: The Complex Dielectric Functionmentioning

confidence: 99%

“…Afterwards, the optical mobility opt and optical resistivity opt of ZnO:Al thin films are calculated by the relations ( 13) and ( 14) [34],…”

Section: The Complex Dielectric Functionmentioning

confidence: 99%

Optical and Dispersion Parameters of the Al-doped ZnO Thin Film

Kashuba¹,

Andriyevsky²,

Ільчук³

et al. 2021

J. Nano- Electron. Phys.

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The results of studies of the dispersion of optical functions and optical constants for zinc oxide thin film doped with aluminum are presented. The deposition of Al-doped ZnO (2.5 wt. %) thin films is performed by magnetron sputtering. Al-doped ZnO thin film crystallizes in a hexagonal structure (structure type ZnO, space group P63mc (No. 186) with unit-cell dimensions a  3.226(2) Å and c  5.155(6) Å (V 46.49(6) Å 3 ). Optical transmittance spectra (300-2500 nm) shows that the Al-doped ZnO thin film is of high optical quality, and the value of the optical band gap (3.26 eV) is very close to undoped samples. The study of optical functions is performed on the basis of the experimentally measured transmission spectrum using the bypass method. The spectral behavior of optical functions, such as refractive index, extinction coefficient, absorption index, dielectric functions and optical conductivity, is established. The value of Urbach energy and the dependence of oscillator strength on the size of the band gap and the concentration of doping element are determined. It is observed an increase in Urbach energy for the Al-doped ZnO thin film in comparison to the undoped ones. An almost twofold increase in the optical oscillator strength value is revealed for the thin film studied. The influence of aluminum doping on the dynamic change of optical mobility, optical resistance and relaxation time is established for the first time for the studied compound. The value of the plasma frequency is also determined and its correlation with the carrier density is defined. The doping of ZnO thin films with aluminum leads to an increase in optical mobility, relaxation time and plasma frequency that is revealed by comparison with reference data for the undoped ZnO. Due to good optical properties, this thin film is a good candidate as a material for optoelectronic devices.

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Effect of Precursor Solvents on the Optical Properties of Copper Oxide Thin Films Deposited Using Spray Pyrolysis for Optoelectronic Applications

Cited by 18 publications

References 30 publications

Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

Optical, Dielectric and Optoelectronic Properties of Spray Deposited Cu-doped Fe2O3 Thin Films

Optical and Dispersion Parameters of the Al-doped ZnO Thin Film

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