• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.969-972
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• 2004

Al doped Zinc Oxide(ZnO:Al) films, which is widely used as a transparent conductor in optoelectronic devices such as solar cell, liquid crystal display, plasma display panel, thermal heater, and other sensors, were prepared by using the capacitively coupled DC magnetron sputtering method. In this paper the effect of doping amounts of $Al_2O_3$ on the electrical, optical and morphological properties were investigated experimentally, The results show that the structural and electrical properties of the film are highly affected by the doping. The optimum growth conditions were obtained for films doped with 2 wt% of Al203 which exhibit a resistivity of $8.5{\times}10^{-4}{\Omega}-cm$ associated with a transmittance of 91.7 % for 840 nm in film thickness in the wavelength range of the visible spectrum.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.4
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• pp.280-286
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• 2010

We have investigated the influence of rapid thermal annealing (RTA) temperature on properties of Al-doped zinc oxide (AZO) thin films deposited on glass substrate by using radio-frequency magnetron sputtering. The RTA is performed in a nitrogen ambient in the temperature range from 300 to $600^{\circ}C$ for 1 minute in a rapid thermal annealer after growing the AZO thin films. The crystallographic structure and the surface morphology of AZO thin film are measured by using X-ray diffraction, and atomic force microscopy and scanning electron microscopy, respectively. The optical transmittance of the deposited thin films is examined in the wavelength range of 300-1100 nm, where the average transmittance is above the 90% in the visible and near-infrared regions. The optical bandgap is calculated from the Tauc's model, and it shows a significant dependence on the RTA temperature. As for the electrical properties of the thin films, the AZO thin film annealed at $400^{\circ}C$ shows the lowest electrical resistivity of $8.6{\times}10^{-3}{\Omega}cm$ and the Hall mobility of $11.3cm^2$/V-sec. These results suggest that the RTA temperature is an important parameter to influence on the structural, electrical, and optical properties of AZO thin films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.77-78
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• 2008

ZnO thin films were deposited on glass substrates by pulsed laser deposition (PLD) at various oxygen pressures. We observed structural, electrical and optical properties of ZnO films. Structural properties were analysed by XRD and FE-SEM. Electrical properties for applications of transparent thin film transistors (TTFTs) were measured by hall measurement using van der pauw methods at room temperature. In order to apply in transparent devices, we measured transmittance, and optical bandgap energy was calculated by Tauc's equation. The results showed that ZnO films deposited at 200mTorr oxygen pressure were applicable to channel layers of transparent TFTs. It had high hall mobilities ($52.92cm^2$/V-s) and suitable transmittance at visible wavelength region (above 80%).

• Journal of Integrative Natural Science
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• v.11 no.2
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• pp.113-120
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• 2018

This study was planned to prepare the high strength hydrogel ophthalmic lens containing isocyanate group and nanoparticles. HDI with carbon nanoparticles were used as additives for the basic combination of HEMA, MA and MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The mixture was heated at $100^{\circ}C$ for an hour to produce the high performance hydrogel ophthalmic lens by cast mold method. Measurement of the physical characteristics of the produced material showed that the refractive index was in the range of 1.4027~1.4600, water content 25.21~44.01%, contact angle $54.18{\sim}72.94^{\circ}$, visible light transmittance 53.03~92.09%, and tensile strength 0.1024~0.2359 kgf and breaking strength was 0.0872~0.2825 kgf. The results showed an increase of refractive index while the decrease in water content. And also, the breaking strength was highest when the addition ratio of HDI was 5%(wt). As a result of the absorbance measurement, no significant difference was observed in all the samples, so it can be judged that the stabilization of nanoparticles in the polymer was maintained.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.5
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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.

• Journal of Sensor Science and Technology
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• v.24 no.4
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• pp.219-223
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• 2015

Indium free consisting of three alternating layers GTO/Ag/GTO has been fabricated by radio-frequency (RF) sputtering for the applications as transparent conducting electrodes and the structural, electrical and optical properties of the gallium tin oxide (GTO) films were carefully studied. The gallium tin oxide thin films deposited at room temperature are found to have an amorphous structure. Hall Effect measurements show a strong influence on the conductivity type where it changed from n-type to p-type at $700^{\circ}C$. GTO/Ag/GTO multilayer structured electrode with a few nm of Ag layer embedded is fabricated and show the optical transmittance of 86.48% in the visible range (${\lambda}$ = 380~770 nm) and quite low electrical resistivity of ${\sim}10^{-5}{\Omega}cm$. The resultant power conversion efficiency of 2.60% of the multilayer based OPV (GAG) is lower than that of the reference commercial ITO. GTO/Ag/GTO multilayer is a promising transparent conducting electrode material due to its low resistivity, high transmittance, low temperature deposition and low cost components.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.1
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• pp.37-43
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• 2012

We were studied that AZO conductive thin film can substitute for FTO electrode in dye sensitized solar cell. Three types of AZO films were deposited on soda-lime glass(AZO/glass, AZO/AZO/glass, textured AZO/AZO/glass) using RF magnetron sputtering process and investigated their properties of electrical, optical, and photoelectric conversion rate. The textured AZO/AZO/glass has the lowest resistivity of $3.079{\times}10^{-4}\;{\Omega}cm$ among other films. And the optical transmittance rate was better than both non textured AZO/AZO/glass and FTO/glass in the visible region. After manufacturing dye solar cells using the three types of AZO films, the textured AZO/AZO/glass showed the highest photoelectric conversion rate of 3.68% among AZO samples. But the transformation rate was slightly lower than FTO cells (4.52%). However, the conductive film of textured AZO/AZO/glass can be applicable to use an electrode in solar cells as cost-effective products.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.114-114
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• 2010

In this study, structural properties and photoluminescent characteristics of thin film rhombohedral zinc orthosilicate doped with manganese ($Zn_2SiO_4:Mn$) were investigated. The $Zn_2SiO_4:Mn$ films showed a pronounced absorption edge in the near ultraviolet wavelength region and a high optical transparency in the visible spectral range. The maximum transmittance reached 0.922 at 597 nm, which was very close to the transmittance of the fused quartz substrate alone (0.935). The $Zn_2SiO_4:Mn$ films were composed of rhombohedral polycrystalline grains with random crystallographic orientation. The broad-band photoluminescence emission peaked at around 525 nm was observed from the $Zn_2SiO_4:Mn$ films, which was ascribed to the radiative relaxation from the $^4T_1$ lowest excitation state to $^6A_1$ ground state of 3d5 electrons in divalent manganese ion. The excitation band exhibited a peak maximum at 259 nm in the near ultraviolet region, which was considered to be associated with the charge transfer transition of divalent Mn ion in the $Zn_2SiO_4$ system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.11
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• pp.1533-1537
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• 2014

$WO_3/Ag/WO_3$ multilayer was researched by using RF magnetron sputtering with transparent electrode. Process gas flow ratio with $Ar/O_2$ were selected the optimum conditions at 70sccm/2sccm and $WO_3$ thin film at its conditions was appeared at transmittance about 80% in the visible light region to the average. $WO_3/Ag/WO_3$ multilayer thin films were fabricated from the same process condition which was the same gas flow ratio of Ar and $O_2$ $WO_3/Ag/WO_3$ thin films were appeared transmittance about 93% and sheet resistance about $6.41{\Omega}/{\square}$. From the SEM images, each thin films were appeared when $WO_3$ is 40nm and $O_2$ is 10nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.143-146
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• 2003

Al doped Zinc Oxide(ZnO:Al) films, which is widely used as a transparent conductor in optoelectronic devices such as solar cell, liquid crystal display, plasma display panel, thermal heater, and other sensors, were prepared by using the capacitively coupled DC magnetron sputtering method. The influence of the substrate temperature, working gas pressure and discharge power on the electrical, optical and morphological properties were investigated experimentally. The consideration on the effect of doping amounts of Al on the electrical and optical properties of ZnO thin film were also carried out. ZnO:Al films with the optimum growth conditions showed resistivity of $9.42{\times}10^{-4}\;{\Omeg}-cm$ and transmittance of 90.88% for 840nm in film thickness in the wavelength range of the visible spectrum.