Determination of optical parameters of zinc oxide nanofibre deposited by electrospinning technique

Abstract

Electrospun ZnO was deposited on a glass substrate from zinc acetate dihydrate (Zn(CH 3 COO) 2 .2H 2 O) with polyvinyl acetate (PVAc) polymer dissolved in N, N, dimethyl formamide (DMF) and annealed in the presence of oxygen until organic molecules were decomposed. The resultant fibre was characterized using scanning electron microscope with energy dispersive spectrophotometry (SEMEDS), Fourier transform infrared (FTIR), and Rutherford backscattering spectroscopy (RBS). SEMEDS and FTIR exhibited a total decomposition of the organic precursor. The mean fibre width was found to be 260 nm, and fibre thickness was measured at 460 nm. XRD patterns indicate that ZnO was corundum with the hexagonal wurtzite structure. The crystallite size was determined by the Debye formula to be 54 nm. The optical analysis indicated that the percentage transmittance increased after calcination. The material band gap for this electrospun ZnO fibre was found to be 3.28 eV. The material optical parameters such as dispersion energy, average oscillator strength, and single oscillator strength were also calculated. The optical conductivity and dielectric plot demonstrated that the material conductivity and dielectric properties increase with increasing photon energy and increase sharply around the material energy bandgap. The Urbach tail analysis of the materials shows that they obey the Urbach rule. Therefore, the n-type electrospun ZnO fibre high refractive index is attributable to the presence of excess oxygen.

Effect of Dip Time on Electrodeposited Zinc Oxide Nanofilm

“…Band gap was determined by extrapolating the straight portion to the photon energy axis at 0, the band gap was found to be between 3.30 eV and 3.60 eV. This band gap values are in line with works reviewed by [7,18,19]. Figure 9 shows the crystal structural studies of the ZnO nanofilm deposited at 30 seconds.…”

“…Many techniques have been used for depositing high quality ZnO thin films. Some of them are electrodeposition technique [5,6], electrospinning technique [7], pulsed laser deposition [8], RF sputtering [9], chemical solution deposition [10,11], electron beam evaporation [12,13], the sol -gel method [14], spray pyrolysis [15,16], ultrasonic spray pyrolysis technique [3].…”

Effect of tin on bandgap narrowing and optical properties of ZnO–Zn2SnO4 electrospun nanofibre composite

“…The concentration of the phases as given by the match3 software for Rietveld refinement shows that the amount of the Zn 2 SnO 4 increases from 51.5% to 61.2% and the ZnO decreases from 48.5% to 38.8% as the concentration of the zinc decreases and tin increases in the sample. In our earlier work [34], we reported the preferred growth direction for ZnO at [100], the shift in the 2θ position for the ZnO in the ZnO-Zn 2 SnO 4 is attributed to the interaction between the ZnO and the Zn 2 SnO 4 . The calculated crystallite size for the diffraction peaks using Scherrer relationship given Equation (1) is 14.78, 13.29, 12.31, 13.57 and 12.69 nm for 5% Sn, 10% Sn, 15% Sn, 20% Sn and 25% Sn respectively.…”

Absorption of electromagnetic waves in sandstone saturated with brine and nanofluids for application in enhanced oil recovery

“…Dielectric and magnetic properties of lossless and lossy materials influence the electromagnetic field distribution. Relative permittivity (ε = ε − jε ) and relative permeability (μ = μ − jμ) defines the dielectric and magnetic properties of the materials, respectively, and influence the reflection of EM waves at the interfaces and the attenuation of the wave within the materials [43,47,48]. Here ε and μ are the real parts and express the energy stored in the material when the electromagnetic field is passed through it.…”