• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.788-791
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• 2002

Tin doped indium oxide(ITO) films are highly conductive and transparent in the visible region whose property leads to the applications in solar cell, liquid crystal display, thermal heater, and other sensors. This paper investigated ITO films as a transparent conducting films for application of PDP. ITO films were grown on glass substrate by RF magnetron sputtering method. To achieve high transmittance and low resistivity, we examined the various film deposition such as substrate temperature, gas pressure, annealing temperature, and deposition time. We recommend the substrate temperature of $500^{\circ}C$ and post annealing of $200^{\circ}C$ in $O_2$ atmosphere for good conductivity and transmittance. From XRD examination, ITO films showed a preferred(222) orientation. As substrate temperature increased from RT to $500^{\circ}C$, the intensity of the (222) peak increased. The highest peak intensity was observed at a substrate temperature of $500^{\circ}C$. with the optimum growth conditions, ITO films showed resistivity of $1.04{\times}10^{-4}{\Omega}-cm$ and transmittance of 81.2% for a film 300nm thick in the wavelength range of the visible spectrum.

• Journal of Electrochemical Science and Technology
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• v.2 no.2
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• pp.68-75
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• 2011

In this review, we have investigated the effect of $TiO_2$-based blocking layers (t-BLs), deposited on a transparent conductive oxide (TCO)-coated glass substrate, on the photovoltaic performance of dye-sensitized solar cells (DSSCs). The t-BL was deposited using spin-coating or sputtering technique, and its thicknesses were varied to study the influence of the thin $TiO_2$ layer in between transparent conducting glass and nanocrystalline $TiO_2$ (nc-$TiO_2$). The DSSC with the t-BL showed the improved adhesion and the suppressed charge recombination at a TCO glass substrate than those without the t-BL, which led to the higher conversion efficiency.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.111.1-111.1
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• 2012

Interest in flexible transparent conducting films (TCFs) has been growing recently mainly due to the demand for electrodes incorporated in flexible or wearable displays in the future. Indium tin oxide (ITO) thin films, which have been traditionally used as the TCFs, have a serious obstacle in TCFs applications. SWNTs are the most appropriate materials for conductive films for displays due to their excellent high mechanical strength and electrical conductivity. In this work, the fabrication by the spraying process of transparent SWNT films and reduction of its sheet resistance on PET substrates is researched Arc-discharge SWNTs were dispersed in deionized water by adding sodium dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWNT was spray-coated on PET substrate and dried on a hotplate. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then was doped with Au-ionic doping treatment, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. This was confirmed and discussed on the XPS and UPS studies. We show that 87 ${\Omega}/{\Box}$ sheet resistances with 81% transmittance at the wavelength of 550nm. The changes in electrical and optical conductivity of SWNT film before and after Au-ionic doping treatments were discussed. The effect of Au-ion treatment on the electronic structure change of SWNT films was investigated by Raman and XPS.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.8
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• pp.591-596
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• 2013

Indium Zinc Tin Oxide (IZTO) thin films were developed as an alternative to Indium Tin Oxide (ITO) thin films. ITO material which has been acknowledged with its low resistivity and optical transparency of 85-90% has been used as major transparent conducting oxide (TCO) materials. However, due to the limited source, high price, and instability problems at high temperature of indium, many researches has been focused on indium-saving TCO materials. Mason Group of Northwestern University was reported to expand the solubility limit up to 40% by co-doping with 1:1 ratio of $Zn^{+2}$ and $Sn^{+4}$ ions. In this study, the properties of IZTO thin films corresponding to Zn/Sn different ratio were investigated. In addition, the effect of substrate temperature variable to the structural, optical and electrical properties of IZTO thin films was investigated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.11
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• pp.36-43
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• 2008

In this parer aluminium-doped zinc oxide(ZnO:Al) conducting layer was deposited on polyethylene terephthalate(PET) substrate by r. f. magnetron sputtering method. The effects of gas pressure and r. f. sputtering power on the structural and electrical properties of ZnO:Al thin film were investigated experimentally. Especially the effect of position of PET substrate on the electrical properties of the film was studied and fixed to improve the electrical properties and also to increase the deposition rate. The results show that the structural and electrical properties of ZnO:Al thin film were strongly influenced by the gas pressure and sputtering power. The minimum resistivity of $1.1{\times}10^{-3}[{\Omega}-cm]$ was obtained at 5[mTorr] of gas pressure, and 18D[W] of sputtering power. The deposition rate of ZnO:Al film at 5[mTorr] of gas pressure was 248[nm/min]. and is higher by around 3 times compared to that at 25[mTorr].

• Current Applied Physics
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• v.18 no.12
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• pp.1583-1591
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• 2018

We analysed perovskite $CH_3NH_3PbI_{3-x}Cl_x$ inverted planer structure solar cell with nickel oxide (NiO) and spiroMeOTAD as hole conductors. This structure is free from electron transport layer. The thickness is optimized for NiO and spiro-MeOTAD hole conducting materials and the devices do not exhibit any significant variation for both hole transport materials. The back metal contact work function is varied for NiO hole conductor and observed that Ni and Co metals may be suitable back contacts for efficient carrier dynamics. The solar photovoltaic response showed a linear decrease in efficiency with increasing temperature. The electron affinity and band gap of transparent conducting oxide and NiO layers are varied to understand their impact on conduction and valence band offsets. A range of suitable band gap and electron affinity values are found essential for efficient device performance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.68-74
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• 2018

All transparent UV photodetector based on ZnO was fabricated with structure of NiO/ZnO/$SnO_2$/ITO by using RF and DC magnetron sputtering system. ZnO was deposited with 4 inch ZnO target (purity 99.99%) for a quality film. In order to build p-n junction up, p-type NiO was formed on n-type ZnO by using reactive sputtering method. The indium tin oxide (ITO) which is transparent conducting oxide (TCO) was applied as a transparent electrode for transporting electrons. To improve the UV photodetector performance, a functional $SnO_2$ layer was selected as an electron transporting and hole blocking layer, which actively controls the carrier movement, between ZnO and ITO. The photodetector (NiO/ZnO/$SnO_2$/ITO) shows transmittance over 50% as similar as the transmittance of a general device (NiO/ZnO/ITO) due to the high transmittance of $SnO_2$ for broad wavelengths. The functional $SnO_2$ layer for band alignment effectively enhances the photo-current to be $15{\mu}A{\cdot}cm^{-2}$ (from $7{\mu}A{\cdot}cm^{-2}$ of without $SnO_2$) with the quick photo-responses of rise time (0.83 ms) and fall time (15.14 ms). We demonstrated the all transparent UV photodetector based on ZnO and suggest the route for effective designs to enhance performance for transparent photoelectric applications.

• Journal of Powder Materials
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• v.26 no.5
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• pp.375-382
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• 2019

Homogeneous multicomponent indium gallium zinc oxide (IGZO) ceramics for transparent electrode targets are prepared from the oxides and nitrates as the source materials, and their properties are characterized. The selected compositions were $In_2O_3:Ga_2O_3:ZnO$ = 1:1:2, 1:1:6, and 1:1:12 in mole ratio based on oxide. As revealed by X-ray diffraction analysis, calcination of the selected oxide or nitrides at $1200^{\circ}C$ results in the formation of $InGaZnO_4$, $InGaZn_3O_6$, and $InGaZn_5O_8$ phases. The 1:1:2, 1:1:6, and 1:1:12 oxide samples pressed in the form of discs exhibit relative densities of 96.9, 93.2, and 84.1%, respectively, after sintering at $1450^{\circ}C$ for 12 h. The $InGaZn_3O_6$ ceramics prepared from the oxide or nitrate batches comprise large grains and exhibit homogeneous elemental distribution. Under optimized conditions, IGZO multicomponent ceramics with controlled phases, high densities, and homogeneous microstructures (grain and elemental distribution) are obtained.

• 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 Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1144-1148
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• 2006

We have investigated liquid crystal (LC) aligning capabilities and electro-optical (EO) characteristics of transparent electrodes as Al-doped ZnO (AZO) substituting indium tin oxide (ITO). The experiment results show that a uniform vertical LC alignment on AZO electrodes based on a rubbed polyimide (PI) surface were achieved. A high pretilt angle of about $88^{\circ}$ was obtained. EO performances of the VA cell on rubbed PI surfaces with AZO electrodes are almost the same as that of the VA cell with ITO electrodes. These results appeared that AZO electrodes as transparent electrodes of LCDs could substitute ITO electrodes.