• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.121.2-121.2
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• 2011

Aluminum-doped Zinc Oxide (AZO) is considered as an excellent candidate to replace Indium Tin Oxide (ITO), which is widely used as transparent conductive oxide (TCO) for electronic devices such as liquid crystal displays (LCDs), organic light emitting diodes (OLEDs) and organic solar cells (OSCs). In the present study, AZO thin film was applied to the transparent electrode of a channel-shaped flexible organic solar cell using a low-temperature selective-area atomic layer deposition (ALD) process. AZO thin films were deposited on Poly-Ethylene-Naphthalate (PEN) substrates with Di-Ethyl-Zinc (DEZ) and Tri-Methyl-Aluminum (TMA) as precursors and $H_2O$ as an oxidant for the atomic layer deposition at the deposition temperature of $130^{\circ}C$. The pulse time of TMA, DEZ and $H_2O$, and purge time were 0.1 second and 20 second, respectively. The electrical and optical properties of the AZO films were characterized as a function of film thickness. The 300 nm-thick AZO film grown on a PEN substrate exhibited sheet resistance of $87{\Omega}$/square and optical transmittance of 84.3% at a wavelength between 400 and 800 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.510-514
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• 1997

The thin film that is electrically conductive and optically transparent is called conductive transparent thin film. ITO(Indium-Tin Oxide) which is a kind of conductive transparent thin film has been widely used in solar cell, transparent electrical heater, selective optical filter, FDP(Flat Display Panel) such as LCD(Liquid Crystal Display), PDP(Plasma Display Panel) and so on. Especially in PDP, ITO films is used as a transparent electrode in order to maintain discharge and decrease consumption power through the improvement of cell structure. In this study, we prepared ITO by reactive r.f. sputtering with indium-tin(Sn 10wt%) alloy target instead of indium-tin oxide target. The ITO films deposited at low temperature 15$0^{\circ}C$ and 8% $O_2$. Partial pressure showed about 3.6 Ω/$\square$. At the end of firing, the resistance of ITO was decreased, the optical transparence was improved above 90%.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.254-257
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• 2008

We have investigated the effect of source/drain electrode deposition method on a performance of top gate structured ZnO TFT performance. TFT using S/D of ITO film, consisted of bi-layer which deposited by ion beam assisted sputtering at the initial stage then deposited by DC magnetron sputtering, showed better performance compared to that using S/D of ITO deposited by just DC magnetron sputtering. Two ITO films exhibited different grain shapes and these resulted in different etching properties. We also suspect that charge trapping on the glass substrate (back channel) during the ITO film deposition may influence the characteristics of top gate structured ZnO TFT.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.162-169
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• 2017

Indium tin oxide (ITO) thin films show a low sheet resistance and high transmittance in the visible range of the spectrum. Therefore, they play an important role as transparent electrodes for flat panel displays. However, their resistivity is rather high for use as a transparent electrode in large displays. One way to improve electrical and optical properties in large displays is to use ITO/Ag/ITO multilayer films. ITO/Ag/ITO multilayer films have lower sheet resistance than single layer ITO films with the same thickness. Prior to the ITO/Ag/ITO multilayer experiments, optimal condition for thickness change are necessary. Their thicknesses were deposited differently in order to analyze electrical and optical properties. However, when optimal single film characteristics are applied to ITO/Ag/ITO multilayer films, other phenomena appeared. After analyzing the electrical and optical properties by changing ITO and Ag film thickness, ITO/Ag/ITO multilayer films were optimized. By combining ITO film at $586\;{\AA}$ and Ag film at 10 nm, the ITO/Ag/ITO multilayer films showed optimized high optical transmittance of 87.65%, and the low sheet resistance of $5.5{\Omega}/sq$.

• Current Photovoltaic Research
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• v.11 no.1
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• pp.13-17
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• 2023

Functional transparent electrode was achieved by metal oxide-metal-Metal oxide (OMO) structure. Tailoring of metal oxide and metal layers, optically transparent and electrically excellent OMO films were investigated. Silver (Ag) is adopted for the metal layer and Ag oxide (AgO) is reactively formed by flowing O₂ gas during the sputtering process. This spontaneous AgO formation from Ag simultaneously provides the good electrical interface with high transparency. Due to the feature of transparent electrode of OMO, it endows the shielding effect (SE) function of electromagnetic interference. Optically transparent and electrically conductive OMO electrode shows the high transmittance (83.7%) and low sheet resistance (6.5 Ω/☐) with SE of 29.54 dB.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.116.1-116.1
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• 2011

Materials with a combination of high electrical conductivity and optical transparency are important components of many electronic and optoelectronic devices such as liquid crystal displays, solar cells, and light emitting diodes. In this study, to fabricate a low-resistance and high optical transparent electrode film for organic photovoltaic, the following steps were performed: the design and manufacture of an electroforming stamp mold, the fabrication of thermal roll imprinted (TRI) poly-carbonate (PC) patterned films, the manufacture of high-conductivity and low-resistance Ag paste which was filled into patterned PC film using a doctor blade process and then coated with a thin film layer of conductive polymer by a spin coating process. As a result of these imprinting processes the PC films obtained a line width of $10{\pm}0.5{\mu}m$, a channel length of $500{\pm}2{\mu}m$, and a pattern depth of $7.34{\pm}0.5{\mu}m$. After the Ag paste was used to fill part of the patterned film with conductive polymer coating, the following parameters were obtained: a sheet resistance of $9.65{\Omega}$/sq, optical transparency values were 83.69 % at a wavelength of 550 nm.

• Journal of information and communication convergence engineering
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• v.3 no.4
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• pp.179-183
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• 2005

A photodiode capable of obtaining a sufficient photo/ dark current ratio at both forward bias state and reverse bias state is proposed. The photodiode includes a glass substrate, an aluminum film formed as a lower electrode over the glass substrate, an alumina film formed as an insulator barrier over the aluminum film, a hydrogenated amorphous silicon film formed as a photo conduction layer over a portion of the alumina film, and a transparent conduction film formed as an upper electrode over the hydro-generated amorphous silicon film. A good quality alumina $(Al_2O_3)$ film is formed by oxidation of aluminum film using electrolyte solution of succinic acid. Alumina is used as a potential barrier between amorphous silicon and aluminum. It controls dark-current restriction. In case of photodiodes made by changing the formation condition of alumina, we can obtain a stable dark current $(\~10^{-12}A)$ in alumina thickness below $1000{\AA}$. At the reverse bias state of the negative voltage in ITO (Indium Tin Oxide), the photo current has substantially constant value of $5{\times}10^{-9}$ A at light scan of 100 1x. On the other hand, the photo/dark current ratios become higher at smaller thicknesses of the alumina film. Therefore, the alumina film is used as a thin insulator barrier, which is distinct from the conventional concept of forming the insulator barrier layer near the transparent conduction film. Also, the structure with the insulator thin barrier layer formed near the lower electrode, opposed to the ITO film, solves the interface problem of the ITO film because it provides an improved photo current/dark current ratio.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.117-121
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• 2010

The composite films were fabricated by air-spray method under the 2 kgf/$cm^2$ pressure using the multi-walled CNTs solution and the nitrocellulose on a 10 ${\mu}m$ polyimide film substrates. We obtained the composite films which were sprayed with the MWCNT dispersion by varying the spray time from 20, 40 and 60sec. The electrical and the optical properties of the sandwiched-structure-composite thin films were investigated by an UV/VIS spectrometer and a Hall Effect equipment. As a result, the optical transmittance of all thin films in the visible range, as well as the electrical conductance shows an available value for the transparent electrode. The carrier concentration and the light transmittance rate for the fabricated sample are between $3.733{\times}10^{10}$ and $6.551{\times}10^{14}cm^{-3}$, around 35 to 95%, respectively.

• Korean Journal of Materials Research
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• v.30 no.3
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• pp.131-135
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• 2020

Silver nanowire (AgNW) networks have been adopted as a front electrode in Cu(In,Ga)Se2 (CIGS) thin film solar cells due to their low cost and compatibility with the solution process. When an AgNW network is applied to a CIGS thin film solar cell, reflection loss can increase because the CdS layer, with a relatively high refractive index (n ~ 2.5 at 550 nm), is exposed to air. To resolve the issue, we apply solution-processed ZnO nanorods to the AgNW network as an anti-reflective coating. To obtain high performance of the optical and electrical properties of the ZnO nanorod and AgNW network composite, we optimize the process parameters - the spin coating of AgNWs and the concentration of zinc nitrate and hexamethylene tetramine (HMT - to fabricate ZnO nanorods. We verify that 10 mM of zinc nitrate and HMT show the lowest reflectance and 10% cell efficiency increase when applied to CIGS thin film solar cells.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1351_1352
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• 2009

We deposited $SnO_2$:F thin films by atomospheric pressure chemical vapor deposition(APCVD) on corning glass. $SnO_2$:F films were used as transparent conductive oxide (TCO) electrode for Si thin film solar cells. We have investigated structural, electrical and optical properties of $SnO_2$:F thin films and fabricated thin film Si solar cells by plasma enhanced CVD(PECVD) on $SnO_2$:F thin films The cells were characterized by I-V measurement using AM1.5 spectra. Conversion efficiency of our cells were between 5.61% and 6.45%.