• Applied Science and Convergence Technology
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• v.25 no.6
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• pp.145-148
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• 2016

This paper, Al-doped ZnO(AZO) thin films for application as transparent conducting oxide films were deposited on the Corning glass substrate by using RF magnetron sputtering system. The effects of various Argon gas flow rates on optical and electrical characteristics of AZO films were investigate sputtering method. The Carrier Concentration is enhanced as Ar gas rate increases, and also the oxygen vacancy concentration. The figure of merit obtained in this study means that AZO films which deposited Ar gas rate of 75 sccm have the highest Carrier concentration and Hall mobility, which have the highest photoelectrical performance that it could be used as transparent electrodes.

• Korean Journal of Materials Research
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• v.23 no.8
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• pp.435-440
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• 2013

Transparent and conducting thin films of Ta-doped $SnO_2$ were fabricated on a glass substrate by a pulse laser deposition(PLD) method. The structural, optical, and electrical properties of these films were investigated as a function of doping level, oxygen partial pressure, substrate temperature, and film thickness. XRD results revealed that all the deposited films were polycrystalline and the intensity of the (211) plane of $SnO_2$ decreased with an increase of Ta content. However, the orientation of the films changed from (211) to (110) with an increase in oxygen partial pressure (40 to 100 mTorr) and substrate temperature. The crystallinity of the films also increased with the substrate temperature. The electrical resistivity measurements showed that the resistivity of the films decreased with an increase in Ta doping, which exhibited the lowest resistivity (${\rho}{\sim}1.1{\times}10^{-3}{\Omega}{\cdot}cm$) for 10 wt% Ta-doped $SnO_2$ film, and then increased further. However, the resistivity continuously decreased with the oxygen partial pressure and substrate temperature. The optical bandgap of the 10 wt% Ta-doped $SnO_2$ film increased (3.67 to 3.78 eV) with an increase in film thickness from 100-700 nm, and the figure of merit revealed an increasing trend with the film thickness.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.1
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• pp.12-16
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• 2020

Indium tin oxide (ITO) films were prepared onto transparent polyimide (PI) substrates by RF magnetron sputtering at room temperature. The deposited ITO films were heat-treated at various temperatures (50, 100, 150, and 200℃). The effect of post heat-treatment temperature on structural, electrical and optical properties of ITO films were investigated. It was found that the as-deposited ITO films were amorphous and the degree of crystallinity and the grain size increased with an increasing heat-treatment temperature, which led to the increase in carrier concentration and mobility. The electrical resistivity of as-deposited ITO films was 2.73 × 10^-3 Ω·cm. With the heat-treatment temperature increasing from 50 to 200℃, the electrical resistivity decreased from 2.93 × 10^-3 to 1.21 × 10^-4 Ω·cm. The average transmittance (400~800 nm) of the ITO deposited PI substrates was decreasing with post heat-treatment temperature and was above 81 % for the temperatures 50~150℃ and decreased considerably to 78 % at 200℃.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.335-335
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• 2014

Over the past several years, transparent conducting oxides have been extensively studied in order to replace indium tin oxide (ITO). Here we report on fluorine doped zinc tin oxide (FZTO) films deposited on glass substrates by radio-frequency (RF) magnetron sputtering using a 30 wt% ZnO with 70 wt% SnO2 ceramic targets. The F-doping was carried out by introducing a mixed gas of pure Ar, CF4, and O2 forming gas into the sputtering chamber while sputtering ZTO target. Annealing temperature affects the structural, electrical and optical properties of FZTO thin films. All the as-deposited FZTO films grown at room temperature are found to be amorphous because of the immiscibility of SnO2 and ZnO. Even after the as-deposited FZTO films were annealed from $300{\sim}500^{\circ}C$, there were no significant changes. However, when the sample is annealed temperature up to $600^{\circ}C$, two distinct diffraction peaks appear in XRD spectra at $2{\Theta}=34.0^{\circ}$ and $52.02^{\circ}$, respectively, which correspond to the (101) and (211) planes of rutile phase SnO2. FZTO thin film annealed at $600^{\circ}C$ resulted in decrease of resistivity $5.47{\times}10^{-3}{\Omega}cm$, carrier concentration ~1019 cm-3, mobility~20 cm2 V-1s-1 and increase of optical band gap from 3.41 to 3.60 eV with increasing the annealing temperatures and well explained by Burstein-Moss effect. Change of work function with the annealing temperature was obtained by ultraviolet photoemission spectroscopy. The increase of annealing temperature leads to increase of work function from ${\phi}=3.80eV$ (as-deposited FZTO) to ${\phi}=4.10eV$ ($600^{\circ}C$ annealed FZTO) which are quite smaller than 4.62 eV for Al-ZnO and 4.74 eV for SnO2. Through X-ray photoelectron spectroscopy, incorporation of F atoms was found at around the binding energy of 684.28 eV in the as-deposited and annealed FZTO up to 400oC, but can't be observed in the annealed FZTO at 500oC. This result indicates that F atoms in FZTO films are loosely bound or probably located in the interstitial sites instead of substitutional sites and thus easily diffused into the vacuum from the films by thermal annealing. The optical transmittance of FZTO films was higher than 80% in all specimens and 2-3% higher than ZTO films. FZTO is a possible potential transparent conducting oxide (TCO) alternative for application in optoelectronics.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.167-167
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• 2005

• Korean Journal of Materials Research
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• v.15 no.4
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• pp.271-274
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• 2005

We investigated the crystalline and electrical properties of ZnO thin films for transparent electrode as a function of the oxygen pressures during the deposition. The ZnO thin films were deposited on a flexible teflon substrates by the pulsed laser deposition. From the X-ray diffraction, ZnO films showed c axis oriented ZnO(0002) crystal structure. The FWHM (full width at half maximum) values decreased from $0.51^{\circ}\;to\;0.34^{\circ}$ as the oxygen pressure increased from 0.1 mTorr to 10.0 mTorr showing the improvement of crystallinity. The resistivity and hall mobility of ZnO film deposited at the oxgen pressure of 0.1 mTorr at $200^{\circ}C$ was about $5\times10^{-4}\Omega{\cdot}cm\;and\;20cm^2/V{\cdot}s$, respectively. The optical transmittance of the ZnO films on flexible teflon substrate was found to be above $85\%$.

• Journal of the Semiconductor & Display Technology
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• v.9 no.1
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• pp.29-33
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• 2010

Recently, the growth of ZnO thin film on glass substrate has been investigated extensively for transparent thin film transistor. We have studied the phase transition of ZnO thin films from metal to semiconductor by changing RF power in the deposition process by RF magnetron sputtering system. The structural, electric, and optical properties of the ZnO thin films were investigated. The film deposited with 75 watt of RF power showed n-type semiconductor characteristic having suitable resistivity $-3.56\;{\times}\;10^{+1}\;{\Omega}cm$, carrier concentration $-2.8\;{\times}\;10^{17}\;cm^{-3}$, and mobility $-0.613\;cm^2V^{-1}s^{-1}$ while other films by 25, 50, 100 watt of RF power closed to metallic films. From the surface analysis (AFM), the number of crystal grain of ZnO thin film increased as RF power increased. The transmittance of the film was over 88% in the visible region regardless of the change in RF power.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.1976-1981
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• 2009

Transparent conducting aluminum-doped zinc oxide (AZO) thin films were deposited on Coming glass substrate using an Gun-type rf magnetron sputtering deposition technology. The AZO thin films were fabricated with an AZO ceramic target (Zn: 98wt.%, $Al_2O_3$: 2wt.%). The AZO thin films were deposited with various growth conditions such as the substrate temperature, oxygen pressure. X -ray diffraction (XRD), UV/visible spectroscope, atomic force microscope (AFM), and Hall effect measurement system were done in order to investigate the properties of the AZO thin films Among the AZO thin films prepared in this study, the one formed at conditions of the substrate temperature $100^{\circ}C$, Ar 50 sccm, $O_2$ 5 sccm and working pressure 5 motor showed the best properties of an electrical resistivity of $1.763{\times}10^{-4}\;[{\Omega}{\cdot}cm]$, a carrier concentration of $1.801{\times}10^{21}\;[cm^{-3}]$, and a carrier mobility of $19.66\;[cm^2/V{\cdot}S]$, which indicates that it could be used as a transparent electrode for thin film transistor and flat panel display applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.394-394
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• 2007

Transparent conductive films can serve as a critical component in displays, solar cells, lasers, optical communication devices, and solid state lighting. Carbon nanotube (CNT) based transparent conductive films are fabricated on glass and polymer substrates. CNTs typically exist in form of quasi-crystalline bundles or highly entangled bundles containing tens of individual nanotubes. To achieve full potential, CNTs must be dispersed in a solvent or other organic media. CNTs are acid treated with nitric acid then the stable dispersion of CNTs in polar solvent such as alcohols, DMF, etc. is achieved by sonication. The solubility of CNTs correlates well with the area ratio of the D and G bands from Raman spectrum. Thin films are formed from well dispersed CNT solutions using spray coating method. CNT thin films exhibit a sheet resistance ($R_s$) of nearby $10^3\;{\Omega}/sq$ with a transmittance of around 80% on the visible light range, which is attributed by excellent dispersion and interaction among CNTs, solvents and polymeric binders.

• Transactions on Electrical and Electronic Materials
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• v.18 no.4
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• pp.217-220
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• 2017

We deposited transparent conductive ZTO/Ag/ZTO trilayer thin films on glass substrates through magnetron sputtering, and then conducted intense electron beam irradiation on their surfaces to investigate the effects of electron irradiation on the structural, optical, and electrical properties of these films. After deposition, we electron irradiated the ZTO/Ag/ZTO films for 10 min at electron energies of 300, 500, and 700 eV. The films that were electron irradiated at 700 eV showed a higher optical transmittance (84.2%) in the visible wavelength region and a lower resistivity ($7.2{\times}10^{-5}{\Omega}cm$) compared with the other films. The figure of merit revealed that the ZTO/Ag/ZTO films that were electron irradiated at 700 eV had a higher optical and electrical performance than the other films prepared in this study.