• 대한금속재료학회지
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• 제50권11호
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• pp.847-854
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• 2012

Al-doped ZnO (AZO) thin films were grown on quartz substrates by the sol-gel method. The effects of the Al mole fraction on the structural and optical properties of the AZO thin films were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-VIS spectroscopy. The particle size of the AZO thin films decreased with an increase in Al concentrations. The optical parameters, the optical band gap, absorption coefficient, refractive index, dispersion parameter, and optical conductivity, were studied in order to investigate the effects of Al concentration on the optical properties of AZO thin films. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at an infinite wavelength of the AZO thin films were affected by the Al incorporation. The optical conductivity of the AZO thin films also increased with increasing photon energy.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.211-212
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• 2012

ZnO submicron particles were grown on Au-catalyzed Si substrate by a vapor phase transport (VPT) growth process under different mixture gas ratio at growth temperature of $900^{\circ}C$. The structural and optical properties of the ZnO submicron particles were investigated by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and photoluminescence (PL). The ZnO submicron particles could be clustered with the $O_2/Ar$ mixture gas ratio(%) higher than 10%, and it was mainly determined by the gas ambient. Particularly, when the $O_2/Ar$ mixture gas ratio was 30%, it was observed the ZnO submicron particles with diameters in the range of 125 to 500 nm and the narrowest full width at half maximum (FWHM) of XRD and PL spectra with $0.121^{\circ}$ and 92 meV, respectively. It was found that the structural and optical properties of the ZnO submicron particles were improved with increasing the $O_2/Ar$ mixture gas ratio through the XRD and PL spectra.

• 한국세라믹학회지
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• 제34권4호
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• pp.420-428
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• 1997

Alumino-borosilicate glasses containing nano-sized CuCl crystals for nonlinear optical application were prepared by the melting and precipitation process, and structural and optical properties were investigated by using XRD, TEM, SAXS, and optical spectroscopy. the average radius of the precipitated CuCl particles was about 2 nm. The blue shift of Z3 resonance peak with decreasing the precipitated CuCl particles size was found and the radius increased with decreasing the glass transition temperature of the matrix glass and with increasing the temperature and duration time of the precipitation heat treatment.

• Smart Structures and Systems
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• 제18권3호
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• pp.471-484
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• 2016

Optical fiber sensors have been proven that they have the potential to detect high-frequency ultrasonic signals, in structural health monitoring field which generally refers to acoustic emission signals from active structural damages and guided waves excited by ultrasonic actuators and propagating in waveguide. In this work, the sensing properties of optical fiber sensors based on Mach-Zehnder interferometer were investigated in the metal plate. Analytical formulas were conducted first to explore the parameters affecting its sensing performances. Due to the simple and definable frequency component, the Lamb wave excited by the piezoelectric wafer was employed to study the sensitivity of the proposed optical fiber sensors with respect to the frequency, rather than the acoustic emission signals. In the experiments, according to above investigations, spiral shape optical fiber sensors with different size were selected to increase their sensitivity. Lamb waves were excited by a circular piezoelectric wafer, while another piezoelectric wafer was used to compare their voltage responses. Furthermore, by changing the excitation frequency, the tuning frequency characteristic of the proposed optical fiber sensor was also investigated experimentally.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1057-1059
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• 2002

ZnO-Si-ZnO multi-layer thin films have been deposited by pulsed laser deposition (PLD). And then, the films have been annealed at $300^{\circ}C$ in oxygen ambient pressure. Electrical properties of the films were improved slightly than ZnO thin film without Si layer. Also, the optical and structural properties changed by Si layer in ZnO thin film. The optical and structural properties of Si-doped ZnO thin films were characterized by PL(Photoluminescence) and XRD(X-ray diffraction method) respectively. Electrical properties were measured by van der Pauw Hall measurements.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.203.2-203.2
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• 2013

Hydrothermally grown ZnO nanorods were synthesized with various Sn contents on quartz substrates, ranging from 0 to 2.5 at% in increment 0.5 at%. Scanning electron microscopy (SEM) and ultraviolet (UV)- visible spectroscopy were used to determine the effect of Sn doping on the structural and optical properties. In the SEM images, the nanorods have hexagonal wurzite structure and the diameter of the nanorods increase with increase in the Sn contents. The optical parameters of the Sn-doped ZnO nanorods such as the absorption coefficients, optical bandgaps, Urbach energies, refractive indices, dispersion parameters, dielectric constants, and optical conductivities were gained from the transmittance and reflectance results. In the PL spectra, the NBE peaks in the UV region decrease and blue-shift with increase in the Sn contents. In addition, the DLE peaks in the visible region of the nanorods shift toward low-energy region when the ZnO nanorods doped with various Sn contents.

• 한국결정성장학회지
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• 제14권4호
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• pp.145-150
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• 2004

We have investigated the structural, electrical and optical properties of Al-doped ZnO (AZO) thin films grown on glass substrate by pulsed DC magnetron sputtering as functions of pulse frequency and substrate temperature. A highly c-axis oriented AZO thin film is grown in perpendicular to the substrate when pulse frequency of 30 kHz and substrate temperature of $400^{\circ}C$ was applied. Under this optimized growth condition, the resistivity of AZO thin films exhibited $7.40\times 10^{-4}\Omega \textrm{cm}$. This indicated that the decrease of film resistivity resulted from the improvement of film crystallinity. The optical transmittance spectra of the films showed a very high transmittance of 85∼90 % in the visible wavelength region and exhibited the absorption edge of about 350 nm. The results show the potential application for transparent conductivity oxide (TCO) thin films.

• 열처리공학회지
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• 제25권5호
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• pp.244-248
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• 2012

ITO/$TiO_2$ films were deposited by RF magnetron sputtering on glass substrates and then the effect of vacuum annealing on the structural, optical and electrical properties of the films was investigated. The structural, optical and electrical properties are strongly related to annealing temperature. The films annealed at $300^{\circ}C$ showed a grain size of 40.9 nm, which was larger than as-deposited amorphous films. The optical transmittance in the visible wavelength region also increased, while the electrical resistivity decreased. The ITO/$TiO_2$ films annealed at $300^{\circ}C$ showed the highest optical transmittance of 81% and also showed the lowest electrical resistivity of $3.05{\times}10^{-4}{\Omega}cm$, in this study.

• 한국재료학회지
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• 제32권5호
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• pp.249-257
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• 2022

Transparent thin films of pure and nickel-doped ZrO₂ are grown successfully by sol-gel dip-coating technique. The structural and optical properties according to the different annealing temperatures (300 ℃, 400 ℃ and 500 ℃) are investigated. Analysis of crystallographic properties through X-ray diffraction pattern reveals an increase in crystallite size due to increase in crystallinity with temperature. All fabricated thin films are highly-oriented along (101) planes, which enhances the increase in nickel doping. Scanning electron microscopy and energy dispersive spectroscopy are employed to confirm the homogeneity in surface morphology as well as the doping configuration of films. The extinction coefficient is found to be on the order of 10^-2, showing the surface smoothness of deposited thin films. UV-visible spectroscopy reveals a decrease in the optical band gap with the increase in annealing temperature due to the increase in crystallite size. The variation in Urbach energy and defect density with doping and the change in annealing temperature are also studied.

• Transactions on Electrical and Electronic Materials
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• 제13권4호
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• pp.185-187
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• 2012

Ga doped ZnO (GZO)/copper (Cu) bi-layered film was deposited on glass substrate by RF and DC magnetron sputtering and then the effect of the Cu bottom layer on the optical, electrical and structural properties of GZO films were considered. As-deposited 100 nm thick GZO films had an optical transmittance of 82% in the visible wavelength region and a sheet resistance of 4139 ${\Omega}/{\Box}$, while the GZO/Cu film had optical and electrical properties that were influenced by the Cu bottom layer. GZO films with 5 nm thick Cu film show the lower sheet resistance of 268 ${\Omega}/{\Box}$ and an optical transmittance of 65% due to increased optical absorption by the Cu metallic bottom layer. Based on the figure of merit, it can be concluded that the thin Cu bottom layer effectively increases the performance of GZO films as a transparent and conducting electrode without intentional substrate heating or a post deposition annealing process.