• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.612-616
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• 2009

Transparent conductive oxide (TCO) films have been widely used in the field of flat panel display industry. Transparent conductive indium zinc oxide (IZO) thin films with excellent chemical stability have attracted much attention as an alternative material for indium tin oxide (ITO) films. In this study, using a $In_2O_3$ and ZnO powder mixture with a ratio of 90 : 10wt% as a target, IZO films were prepared on polynorbornene (PNB) substrates by electron beam evaporation. The effect of substrate temperature and $O_2$ introduction flow rate were investigated in terms of electrical and optical properties of deposited IZO films. The best electrical and optical properties we obtained from this study were sheet resistance value of $5.446{\times}10^2{\Omega}/{\boxempty}$ and optical transmittance of 87.4% at 550 nm at $O_2$ introduction flow rate of 4 sccm, deposition rate of $2{\AA}$/sec, thickness of 1000 $\AA$ and substrate temperature of $150^{\circ}C$.

• 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.

• Journal of the Korean Ceramic Society
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• v.31 no.4
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• pp.436-447
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• 1994

ZnO transparent conducting thin film, which is a strong candidate for a transparent electrical contact in optoelectronic devices, was prepared by the vapour spraying method on the slide glass in nitrogen ambient at the atmospheric pressure. The structural, optical and electrical properties of films show a strong dependence on substrate temperature, and the optimum range of deposition temperature existed to obtain TCO(Transparent Conducting Oxide) films. At the higher temperatures, milky films were obtained. In such optimum range, the bandgap in ZnO films was determined from the spectral dependence of absorption coefficient and electrical characteristics were characterized with by the Hall mobility and carrier concentration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.525-528
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• 2001

ZnO:Al thin film can be used as a transparent conducting oxide(TCO) which has low electric resistivity and high optical transmittance for the front electrode of amorphous silicon solar cells and display devices. This study of electrical, crystallographic and optical properties of Al doped ZnO thin films prepared by Facing Targets Sputtering (FTS), where strong internal magnets were contained in target holders to confine the plasma between the targets, is described. Optimal transmittance and resistivity was obtained by controlling flow rate of O$_2$ gas and substrate temperature. When the of gas rate of 0.3 and substrate temperature 200$^{\circ}C$ , ZnO:Al thin film had strongly oriented c-axis and lower resistivity(<10$\^$-4/Ω-cm).

• Journal of Sensor Science and Technology
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• v.28 no.4
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• pp.236-239
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• 2019

In this work, we performed an optical simulation study on the performance of a PMDPP3T:PCBM based on an organic photovoltaic (PV) device. The virtual PV device was developed in Lumerical, finite-difference time-domain (FDTD) solutions. Different layers of the PV cell have been defined through the incorporation of complex refractive index value of those layers' constituent materials. During the simulation study, the effect of the variation active layer thickness on an ideal short circuit current density ($J_{sc,ideal}$) of the PV cell has been, first, observed. Thereafter, we have investigated the impact of surface roughness of a transparent conducting oxide (TCO) electrode on $J_{sc,ideal}$ of the PV cells. From this simulation, it has been observed that the $J_{sc,ideal}$ value of the PV cell is strongly dependent on the thickness of its active layer and the photon absorption of the PV cell has gradually decreased with the increment of the TCO's surface roughness. As a result, the capability of the PV device has been reduced with the increment of the surface roughness of the TCO.

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.699-707
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• 1995

The material that is both conductive in electricity and transparent to the visible ray is called transparent conducting thin film. It has many fields of application such as Solar Cell, Liquid Crystal display, Vidicon on T.V, transparent electrical heater, selective optical filter, and a optical electric device , etc. In the recent papers on several TCO( transparent conducting oxide ) material, the study is mainly focusing on ITO(indium tin oxide) because ITO shows good results on both optical and electrical properties. Nowaday, in the development of LCD(Liquid Crystal display), the low temperature process to reduce the production cost and to deposit ITO on polymer substrate (or low melting substrate) has been demanded. In this study, we prepared indium tin oxide(ITO) by a cylindrical DC magnetron sputtering with Indium-tin (9:1) alloy target instead of indium-tin oxide target. The resistivity of the film deposited in oxygen partial pressure of 5% and substrate temperature of 140.deg. C. is 1.6*10$\^$-4/.ohm..cm with 85% optical transmission in viaible ray.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.163-167
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• 2013

Aluminum doped zinc oxide (AZO) thin films have been prepared on the glass substrates (Corning 1737) by sol-gel dip-coating method employing zinc acetate and aluminum chloride hexahydrate for the transparent conducting oxide (TCO) applications. 1 at% Al was doped to the ZnO thin films. The effects of post-heating temperature on the crystallization, optical and electrical properties of the AZO films have been investigated. Experimental results showed that post-heating temperature affected the microstructure, electrical resistance, and optical transmittance of the AZO films. From the X-ray diffraction analysis, all films have hexagonal wurtzite crystal structure. Optical transmittance spectra of the AZO films exhibited transmittance higher than about 80% within the visible wavelength region and the optical direct band gap ($E_g$) of these films was increased with increasing post-heating temperature. A minimum resistivity of $2.5{\times}10^{-3}{\Omega}cm$ was observed at $650^{\circ}C$.

• 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.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1281-1282
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• 2008

Low cost TCO(Transparent Conductive oxide) thin films were prepared by 3" DC/RF magnetron sputtering systems. For the AZO preparation processes a 99.99% AZO target (Zn: 98 wt.%, $Al_2O_3$: 2 wt.%) was used. In order to verify feasibility of the AZO thin films to organic light emitting device (OLED) application, test organic light emitting device was fabricated based on AZO as TCO, TPD as hole transporting layer (HTL), Alq3 as both emitting layer (EML) and electron transporting layer (ETL), and aluminium as cathode, where the both ITO and AZO surfaces were treated using $O_2$ RF plasma. The I-V characteristics of the AZO/TPD/Alq3/Al OLEDs were evaluated. As the results, the performance of the OLEDs with AZO as transparent conducting anode could be useable.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.175-175
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• 2013

염료감응형 태양전지(Dye Sensitized Solar Cells; DSSC)에서 투명전극(Transparent Conducting Oxide; TCO)으로 사용되는 ITO, FTO의 경우 자원의 희소성과 고온에 취약하며 취성과 같은 단점 등이 있다. Graphene은 단원자층의 얇은 물질로써 우수한 전도도와 투과도, 고강도와 고탄성의 특성들을 가진다. 이러한 특성들을 가지는 Graphene을 기존의 투명전극을 대체하여 DSSC의 작업전극에 적용 하였다. 본 실험에서 사용된 그래핀 시트는 근적외선을 source로 하는 RTA (Rapid Thermal Annealing)장비에 탄화수소 기반의 gas를 주입하여 Ni위에 성장시켰으며, 습식방법인 용액Etching 방식을 사용하여 유리판 위에 전사시켰다. 전사된 Graphene 투명전극의 전기적 특성과 광학적 특성을 평가하기 위해 4 point probe, FT-IR, 마이크로 Raman분광법, 광학현미경 및 투과도를 측정하여 평가 하였다. 전사된 Graphene 투명전극을 염료감응형 태양전지 작업전극에 적용하여, DSSC소자를 제작하고, Solar Simulator로 광전변환효율 및 EIS(Electrochemical Impedance Spectroscopy)를 측정하여 기존의 FTO로 만든 DSSC와 비교하였다.