• Journal of the Korean Ceramic Society
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• v.39 no.9
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• pp.840-845
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• 2002

As an ozone gas sensor, the semiconductor gas sensor which is cheap, portable and simple in use and has a high sensitivity and an excellent selectivity, has been known as an alternative. In the present study, ITO ($In_2O_3 95%,\;SnO_2$ 5%) thin films were deposited on the alumina substrate by using R.F. magnetron sputtering method. The substrate temperature was 300$^{\circ}C$ and 500$^{\circ}C$, respectively and then some specimens were annealed at 500$^{\circ}C$ for 4h in air. ITO gas-sensing films formed crystallines before and after annealing. As results of gas sensitivity measurements to an ozone gas, the sensor deposited at 300$^{\circ}C$ and then annealed has the highest sensitivity (sensible below 1 ppm). As the operating temperature increased gradually, the sensitivity decreased but the response time and stability improved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.857-860
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• 2002

The material that is both conductive in electricity and transparent to the visible-ray is called transparent conducting thin film. It has many field of application such as solar cell, liquid crystal display, transparent electrical heater, selective optical filter, and a optical electric device. In this study, indium tin oxide (ITO ; Sn-doped $In_2O_3$) thin films were deposited on $SiO_2$/soda-lime glass plates by a dc magnetron sputtering technique. The crystallinity and electrical properties of the films were investigated by X-ray diffraction(XRD), atomic force microscopy (AFM) scanning and 4-point probe. The optical transmittance of ITO films in the range of 300-1000nm were measured with a spectrophotometer. As a result, we obtained polycrystalline structured ITO films with (222), (400), and (440) peak. Transmittance of all the films were higher than 90% in the visible range.

• Journal of the Korean Ceramic Society
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• v.38 no.1
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• pp.100-105
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• 2001

An all solid-state thin film battery (TFB) was fabricated by growing, undoped and Pt-doped vanadium oxide cathode film ( $V_2$ $O_{5}$ ) on I $n_2$ $O_3$: Sn coated glass, respectively. Room temperature charge-discharge measurements based on Li/Lipon/ $V_2$ $O_{5}$ full-cell structure with a constant current clearly shows that the Pt-doped $V_2$ $O_{5}$ cathode film is superior, in terms of cyclibility. X-ray diffraction (XRD) results indicate that the Pt doping process induces a more random amorphous structure than an undoped $V_2$ $O_{5}$ film. In addition to its modified structure, the Pt-doped $V_2$ $O_{5}$ film has a smoother surface than the undoped sample. Compared to an undoped $V_2$ $O_{5}$ film, the Pt doped $V_2$ $O_{5}$ cathode film has a higher electron conductivity. We hypothesize that the addition of Pt alters electrochemical performance in a manner of making more random amorphous structure and gives an excess electron by replacing the $V^{+5}$. Possible mechanisms are discussed for the observed Pt doping effect on structural and electrochemical properties of vanadium oxide cathode films, which are grown on I $n_2$ $O_3$: Sn coated glass.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.168-168
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• 2010

Transparent conduction oxides (TCOs) films is extensively reported for optoelectronic devices application such as touch panels, solar cells, liquid crystal displays (LCDs), and organic light emitting diodes(OLEDs). Among the many TCO film, indium tin oxide(ITO) is in great demand due to the growth of flat panel display industry. However, indium is not only high cost but also its deposits dwindling. Therefore, many studies are being done on the transparent conductive oxides(TCOs). We fabricated a target of IZTO(In2O3:ZnO:SnO2=70:15:15 wt.%) reduced indium. Then, IZTO thin films were deposited on glass substrates by pulsed DC magnetron sputtering with various oxygen flow ratio. The substrate temperature was fixed at the room temperature. We investigated the electrical, optical, structural properties of IZTO thin films. The electrical properties of IZTO thin films were dependent on the oxygen partial pressure. As a result, the most excellent properties of IZTO thin films were obtained at the 3% of oxygen flow rate with the low resistivity of $7.236{\times}10^{-4}{\Omega}cm$. And also the optical properties of IZTO thin films were shown the good transmittance over 80%. These IZTO thin films were used to fabricated organic light emitting diodes(OLEDs) as anode and the device performances studied. The OLED with an IZTO anode deposited at optimized deposition condition showed good brightness properties. Therefore, IZTO has utility value of TCO electrode although it reduced indium and we expect it is possible for the IZTO to apply to flexible display due to the low processing temperature.

• Korean Journal of Materials Research
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• v.9 no.5
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• pp.533-537
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• 1999

ATO(Sb doped $SnO_2$) thin films whose thicknesses were 600, 1100 and $2100\AA$ were prepared by DC magnetron sputtering method. They showed the lowest resistivity at DC sputtering power 0.24kW and had lower resistivity with increasing thickness. The power dependence of resistivity among ATO thin films was also different with thickness. The increase of carrier concentration in ATO thin films was responsible for the decrease of resistivity with thickness increase. ATO thin films which were prepared at 30sccm oxygen flow rate showed a great change of sheet resistance under 1M HCl solution. The investigation of SAM(Scanning Auger Microprobe) revealed that oxygen atomic percentage on the surface of ATO thin films was changed. The decrease of sheet resistance also occurred when ATO thin films, prepared at 30sccm oxygen flow rate, were exposed to air for a long period of time. For this reason, it was considered that the desorption of oxygen on ATO surface was accelerated by HCl.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.167-167
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• 2010

Indium tin oxide (ITO) has been widely used as transparent conductive oxides (TCOs) for transparent electrodes of various optoelectronic devices, such as liquid crystal displays (LCD) and organic light emitting diodes (OLED). However, indium has become increasingly expensive and rare because of its limited resources. In addition, ITO thin films have some problems for OLED and flexible displays, such as imperfect work function, chemical instability, and high deposition temperature. Therefore, multi-component TCO materials have been reported as anode materials. Among the various materials, IZTO thin films have been gained much attention as anode materials due to their high work function, good conductivity, high transparency and low deposition temperature. IZTO thin films with a thickness of 200nm were deposited on Corning glass substrate at different substrate temperature by pulsed DC magnetron sputtering with a sintered ceramic target of IZTO (In2O3 70 wt%, ZnO 15 wt%, SnO2 15 wt%). We investigated the electrical, optical, structural properties of IZTO thin films. As the substrate temperature is increased, the electrical properties of IZTO are improved. All IZTO thin films have good optical properties, which showed an average of transmittance over 80%. These IZTO thin films were used to fabricate organic light emitting diodes (OLEDs) as anode and the device performances studied. As a result, IZTO has utility value of TCO electrode although it reduced indium and we expect it is possible for the IZTO to apply to flexible display due to the low processing temperature.

• Korean Journal of Materials Research
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• v.10 no.11
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• pp.778-783
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• 2000

Effects of the $Al_2$O$_3$surface protective layer, deposited on the SnO$_2$sensing layer by aerosol flame deposition (AFD) method, on the sensing properties of SnO$_2$thin film ags sensors were investigated.Effects of Pt doping to the $Al_2$O$_3$surface protective layer on the selectivity of CH$_4$ gas were also investigated. 0.3$\mu\textrm{m}$ thick SnO$_2$thin sensing layers on Pt electrodes were prepared by R.F. magnetron sputtering with R.F. power of 50 W, at working pressure of 4mTorr, and at 20$0^{\circ}C$ for 30 min. $Al_2$O$_3$surface protective layers on SnO$_2$layers were prepared by AFD using a diluted aluminum nitrade (Al(NO$_3$).9$H_2O$) solution. The sensitivity of CO gas in the SnO$_2$gas sensor with an $Al_2$O$_3$surface protective layer was significantly decreased. But that of CH$_4$gas remained almost same with pure SnO$_2$gas sensor. This result shows that the selectivity of CH$_4$gas is increased because of the $Al_2$O$_3$surface protective layer. In the case of SnO$_2$gas sensors with Pt-doped $Al_2$O$_3$surface protective layers, low sensing property to CO gas and high sensing property to CH$_4$were observed. This results in the increasing of selectivity of CH$_4$gas selectivity are discussed.

• Korean Journal of Materials Research
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• v.19 no.5
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• pp.245-252
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• 2009

Changes in the surface morphology and light scattering of textured Al doped ZnO thin films on glass substrates prepared by rf magnetron sputtering were investigated. As-deposited ZnO:Al films show a high transmittance of above 80% in the visible range and a low electrical resistivity of $4.5{\times}10^{-4}{\Omega}{\cdot}cm$. The surface morphology of textured ZnO:Al films are closely dependent on the deposition parameters of heater temperature, working pressure, and etching time in the etching process. The optimized surface morphology with a crater shape is obtained at a heater temperature of $350^{\circ}C$, working pressure of 0.5 mtorr, and etching time of 45 seconds. The optical properties of light transmittance, haze, and angular distribution function (ADF) are significantly affected by the resulting surface morphologies of textured films. The film surfaces, having uniformly size-distributed craters, represent good light scattering properties of high haze and ADF values. Compared with commercial Asahi U ($SnO_2$:F) substrates, the suitability of textured ZnO:Al films as front electrode material for amorphous silicon thin film solar cells is also estimated with respect to electrical and optical properties.

• Journal of Ocean Engineering and Technology
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• v.21 no.1 s.74
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• pp.59-63
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• 2007

The thin film of indium tin oxide (ITO) was prepared using the inclination opposite target type DC magnetron sputtering equipment onto the glass substrate at room temperature, using oxidized ITO with In2O3 and SnO2in a weight ratio of 9:1. The elastic modulus and hardness of the ITO thin films, prepared at different deposition conditions, were determined through anano-indentation experiment. The work pressure was varied from $2.6{\times}10-1\;to\;8.3{\times}10-1Pa$. The results show that the variation of work pressure during film deposition could vary significantly, according to the elastic modulus and hardness of the ITO thin films. It also can be seen that a minimum value exists in the film resistivity for the ITO thin films, prepared according to the variation of work pressure. However, the ITO film produced at room temperature had a microstructure in which a X ray diffraction peak is not clear, regardless of the work pressure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.961-968
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• 2009

In this work, transparent conductive oxide(TCO) films such as $In_2O_3-SnO_2$(ITO) and $In_2O_3-ZnO$(IZO) were prepared on polyethylene naphthalene(PEN) and glass substrates by using rf-magnetron sputtering system. The TCO films deposited on PEN substrate show very poor conductivity as compared to that of the TCO films deposited on glass substrates. From the results of the residual gas analysis(RGA) test, this poor stability of plastic substrate is presumed to be caused by the deteriorated adhesion between the TCO films and the plastic substrate due to outgassing from the plastic substrate during deposition of TCO films. From our experiment, it is found that the vaporization of some defects in the plastic substrates deteriorate the adhesion of the TCO films to the plastic substrate, because the most plastic substrates containing the water vapor and/or other adsorbed particles such as organic solvents. Mixing of these gases vaporized in the sputtering process will also affect the electrical property of the deposited TCO films. Inorganic thin composite $(SiO_2)_{40}(ZnO)_{60}$ film as a gas barrier layer is coated on the PEN substrate to protecting the diffusion of vapors from the substrate, so that the TCO films with an improved quality can be obtained.