Role of oxygen concentrations on structural and optical properties of RF magnetron sputtered ZnO thin films

Otieno, Francis; Airo, Mildred; Ganetsos, Theodore; Erasmus, Rudolph M.; Billing, David G.; Quandt, Alexander; Wamwangi, Daniel

doi:10.1007/s11082-019-2076-5

Cited by 8 publications

(5 citation statements)

References 37 publications

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“…This is likely because, at low RF plasma power, some of the zinc atoms can be masked by the incoming species before being oxidized. These results are in excellent agreement with those of El-Hossary et al and Otieno et al. , Otieno et al, in turn, stated that an increasing stoichiometry, Zn/O ratio, leads to an increase in the strain and the dislocation density of the ZnO films. These outcomes are also consistent with the field emission scanning electron microscopy images since the RF plasma power affects the morphology of the ZnO films.…”

Section: Resultssupporting

confidence: 91%

Impact of Radio Frequency Plasma Power on the Structure, Crystallinity, Dislocation Density, and the Energy Band Gap of ZnO Nanostructure

et al. 2021

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The aim of this study is to investigate the effect of radio frequency (RF) plasma power on the morphology, crystal structure, elemental chemical composition, and optical properties of ZnO nanostructure using a direct current magnetron sputtering technique. This study emphasized that the growth rate and surface morphology of the polycrystalline ZnO were enhanced as the radio frequency (RF) plasma power increased. This can be observed by fixing other parameters such as the growth time, substrate temperature, and chamber partial pressure. The RF plasma power alteration from 150 to 300 W can produce uniform nanograin, spheroid, and nanorods. Additionally, the RF plasma power alteration leads to the alteration in the ZnO nanorod diameter from 14 to 202 nm. It was observed that the XRD intensities are increased at higher plasma powers. This, perhaps, can be inferred from the transformation of the granular microcrystals to the needlelike or platelike large crystals, as already examined using SEM images. This also has an impact on the average crystalline size, which increased from 10 to 40 nm on increasing the RF plasma power. Moreover, the increase of the RF plasma power has an obvious impact upon the optical band-gap energy, which was accordingly decreased from 3.26 to 3.22 eV. Finally, the absorption band edge was shifted to a lower-energy region due to the quantum size effect at the nanorange.

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Section: Resultssupporting

confidence: 91%

Impact of Radio Frequency Plasma Power on the Structure, Crystallinity, Dislocation Density, and the Energy Band Gap of ZnO Nanostructure

et al. 2021

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“…The sharp and well-defined peaks of (002) are observed in all AZO samples. The (002) plane of AZO films corresponds to a diffraction angle value of 2θ ~ 34°, showing the hexagonal structure of wurtzite and the high intensity growth orientation along the c-axis direction as the oxygen content progressively rises (Hwang et al, 2011;Otieno et al, 2019) (see Fig. 1b).…”

Section: Resultsmentioning

confidence: 99%

<span>Effect of limited oxygen gas flux on properties of Al-doped ZnO films</span>

Le,

Tran,

Nguyen

et al. 2024

Dong Thap University Journal of Science

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In this study, Al-doped ZnO thin films were sputter deposited on glass substrate as a function of limited oxygen gas inlet. The crystal structure, optical, and electrical properties of the films were characterized using X-ray diffraction, scanning electron microscopy, UV-Vis spectroscopy, and Hall measurement. High crystallinity was found in all AZO samples. Surface morphology presented small grain size of ~ 50 – 100 nm, and thickness of AZO thin films were maintained approximately at 280 nm. Average optical transmittance of AZO films was about 90% in the 450 – 600 nm region, and optical band-gap values varied from 3.327 to 3.380 eV. The electrical resistivity of AZO films decreased with an increasing amount of oxygen flux. These AZO films are quite appropriate for the perspective development of UV photodetectors as a central role absorbing components or n-type semiconducting layers.

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“…In order to deposit stoichiometric films, it is necessary to optimize sufficient amount of oxygen with argon in the sputtering system. Accordingly, the obtained films were deposited with argon (Ar) at a flow rate of 30 sccm and oxygen (O 2 ) at 99.999 purity and 0.5 sccm as sputtering and reactive gases to suppress the oxygen vacancies that act as annihilators of holes during film deposition according to Otieno et al [25]. The RF power used was 200 W. The depositions were performed with a RF magnetron sputtering PlasmalabSystem400 (Oxford Instruments, Abingdon, UK).…”

Section: Ca-doped Zno:al Thin Film Synthesismentioning

confidence: 99%

Ca-Doped ZnO:Al Thin Films: Synthesis and Characterization

et al. 2021

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We unveiled the effect of doping on the morpho-structural and opto/electrical properties of Ca-doped ZnO:Al thin films obtained by RF magnetron sputtering. Scanning electron microscopy (SEM) was performed to reveal the surface morphology, while the composition and crystal structure were investigated by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The correlation between the microstructure and the electrical conductivity identifies an increase in electrical conductivity up to 145 × 10−3 Ω−1·m−1 at 5 wt.% Ca doping level with the decrease in the grain size. Furthermore, the presence of Ca dopant triggers the occurrence of the emission peak at 430 nm and an increase of the green emission peak in PL spectra. Corroborating the electrical measurements with X-ray diffraction and optical measurements, one can infer that the electrical conductivity is dominated by intrinsic defects developed during deposition and by the existence of dopants.

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Role of oxygen concentrations on structural and optical properties of RF magnetron sputtered ZnO thin films

Cited by 8 publications

References 37 publications

Impact of Radio Frequency Plasma Power on the Structure, Crystallinity, Dislocation Density, and the Energy Band Gap of ZnO Nanostructure

Impact of Radio Frequency Plasma Power on the Structure, Crystallinity, Dislocation Density, and the Energy Band Gap of ZnO Nanostructure

<span>Effect of limited oxygen gas flux on properties of Al-doped ZnO films</span>

Ca-Doped ZnO:Al Thin Films: Synthesis and Characterization

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