• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1528.1-1529
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• 2011

Scribing the transparent conductive oxide(TCO) is an essential technology for the large scaled dye-sensitized solar cell(DSC) and the commercialization of the DSC. Laser systems are most used for scribing technology due to their precision. However, it is difficult to generalize systems because most systems are large and heavy. In this study, we tried to simplificate the Nd:YAG laser system for scribing TCO of the DSC by using switched mode power supply(SMPS) technique. The continuous conduction mode booster converter topology is applied and MC34262 power factor controller is used for the variable frequency control. Finally, SMPS circuit which specifications are 400W of capacity, 400V DC output and 98% of efficiency is fabricated. And it is demonstrated that the scribing TCO is completed by the Nd:YAG laser using this SMPS circuit.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.207-207
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• 2011

Amorphous transparent oxide semiconductors (a-TOS) have been widely studied for many optoelectronic devices such as AM-OLED (active-matrix organic light emitting diodes). Recently, Nomura et al. demonstrated high performance amorphous IGZO (In-Ga-Zn-O) TFTs.1 Despite the amorphous structure, due to the conduction band minimum (CBM) that made of spherically extended s-orbitals of the constituent metals, an a-IGZO TFT shows high mobility.2,3 But IGZO films contain high cost rare metals. Therefore, we need to investigate the alternatives. Because Aluminum has a high bond enthalpy with oxygen atom and Alumina has a high lattice energy, we try to replace Gallium with Aluminum that is high reserve low cost material. In this study, we focused on the electrical properties of IZO:Al thin films as a channel layer of TFTs. IZO:Al were deposited on unheated non-alkali glass substrates (5 cm ${\times}$ 5 cm) by magnetron co-sputtering system with two cathodes equipped with IZO target and Al target, respectively. The sintered ceramic IZO disc (3 inch ${\phi}$, 5 mm t) and metal Al target (3 inch ${\phi}$, 5 mm t) are used for deposition. The O2 gas was used as the reactive gas to control carrier concentration and mobility. Deposition was carried out under various sputtering conditions to investigate the effect of sputtering process on the characteristics of IZO:Al thin films. Correlation between sputtering factors and electronic properties of the film will be discussed in detail.

• 멤브레인
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• 제33권5호
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• pp.248-256
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• 2023

ITO 투명 전극 필름은 디스플레이, 전기 자동차 등 산업 전 범위에서 널리 사용되는 전자 재료이다. 본 연구에서는 이러한 indium tin oxide (ITO) 필름의 열성형 안정성을 향상시키기 위하여 Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) 전도성 고분자 코팅 용액 조성을 결정하였다. 1000 S/cm의 고 전도성을 보이는 PEDOT:PSS 용액에 끓는점이 각기 다른 4가지 종류의 용매를 희석하였고, 코팅 전 후 면저항 변화를 분석하였다. 또한 380~800 nm 영역의 광 투과율 분석 및 Raman 스펙트럼 분석을 통하여 PEDOT:PSS 박막이 코팅된 ITO 투명 전극의 전기적 특성 결정 메커니즘을 규명하였다. 230℃ 열성형 공정 결과 ITO 필름은 113% 연신 상태에서 이미 전기 전도성을 읽었지만, ethylene glycol을 희석 용매로 사용하여 얻어진 전도성 고분자 박막이 적용된 ITO 필름은 126% 고 연신 상태에서도 초기 60 Ω/sq 면저항을 246 Ω/sq로 유지하는 우수한 전기 전도성을 보였다.

• Journal of information and communication convergence engineering
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• 제3권4호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.355-358
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• 1988

Polycrystalline transparent semiconducting zinc oxide film has been characterized for their electrical properties. The conductivity of the film could be increased by approximately five times of magnitude by annealing it in hydrogen at 400 C. The electrical properties measured on the temperature range of RT to 120 K give support well to the model which depicts the importance of the grain boundary effects on the electrical conduction of zinc oxide film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.446-447
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• 2007

Aluminisum-doped zinc oxide (AZO) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with indium tin oxide (ITO). In our paper, AZO films have been deposited on glass (coming 1737) substrates by RF magnetron sputtering. The AZO film was post-annealed at $600^{\circ}C$, $800^{\circ}C$ for 2 hr with $N_2$ atmosphere, respectively. We investigated that the electric properties and qualitative analysis of AZO films, which measured using the methods of Hall effect, X-ray photoelectron spectroscopy (XPS).

• 한국재료학회지
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• 제20권4호
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• pp.175-180
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• 2010

Transparent conducting oxide (TCO) films are widely used for optoelectronic applications. Among TCO materials, zinc oxide (ZnO) has been studied extensively for its high optical transmission and electrical conduction. In this study, the effects of $O_2$ plasma pretreatment on the properties of Ga-doped ZnO films (GZO) on polyethylene naphthalate (PEN) substrate were studied. The $O_2$ plasma pretreatment process was used instead of conventional oxide buffer layers. The $O_2$ plasma treatment process has several merits compared with the oxide buffer layer treatment, especially on a mass production scale. In this process, an additional sputtering system for oxide composition is not needed and the plasma treatment process is easily adopted as an in-line process. GZO films were fabricated by RF magnetron sputtering process. To improve surface energy and adhesion between the PEN substrate and the GZO film, the $O_2$ plasma pre-treatment process was used prior to GZO sputtering. As the RF power and the treatment time increased, the contact angle decreased and the RMS surface roughness increased significantly. It is believed that the surface energy and adhesive force of the polymer surfaces increased with the $O_2$ plasma treatment and that the crystallinity and grain size of the GZO films increased. When the RF power was 100W and the treatment time was 120 sec in the $O_2$ plasma pretreatment process, the resistivity of the GZO films on the PEN substrate was $1.05\;{\times}\;10^{-3}{\Omega}-cm$, which is an appropriate range for most optoelectronic applications.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.426.1-426.1
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• 2014

For high performance thin film solar cells, texturing surface, enhancing the optical absorptionpath, is pretty important. Textured ZnO:Al transparent oxide layer of high haze is commonly used in Si thin film solar cells. In this paper, novel deposition method for aluminum doped zinc oxide (ZnO:Al) on glass substrates is presented to improve the haze property. The broccoli structure of ZnO:Al layer was formed on chemically etched glass substrates, which showed high haze value on a wide wavelength range.The etching condition of the glass substrates can change not only the haze values of the ZnO:Al of in-situ growth but alsothe electrical and optical properties of the deposited ZnO:Al films.The etching mechanism of the glass substrate affecting on the surface morphology of the glass will be discussed, which resulted in variation of texture of ZnO:Al layer. The optical properties of substrate morphology were also analyzed with EDS and FTIR results. As a result, the high haze value of 85.4% was obtained in the wavelength range of 300 nm to 1100 nm. Furthermore, low sheet resistance of about 5~18 ohm/sq was achieved for different surface morphologies of the ZnO:Al films.

• Journal of Magnetics
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• 제13권3호
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• pp.88-91
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• 2008

This study examined the effect of Sn co-doping on the transport and magnetic properties of Cr-doped $In_2O_3$ thin films grown on (100) silicon substrates by pulsed laser deposition. The experimental results showed that Sn co-doping enhances the magnetization and appearance of the anomalous Hall effect, and increases the carrier (electron) concentration. These results suggest that the conduction carrier plays an important role in enhancing the ferromagnetism of a laser-deposited Cr-doped $In_2O_3$ film, which may have applications in transparent oxide semiconductor spin electronics devices.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.13-16
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• 2012

Zinc oxide (ZnO) films were deposited by an RF magnetron sputtering system with the RF power of 200W and 300W and flow rate of oxygen gases of 20 and 30 sccm, in order to research the growth of ZnO on carbon doped silicon oxide (SiOC) thin film. The reflectance of SiOC film on Si film deposited by the sputtering decreased with increasing the oxygen flow rate in the range of long wavelength. In comparison between ZnO/Si and ZnO/SiOC/Si thin film, the reflectance of ZnO/SiOC/Si film was inversed that of ZnO/Si film in the rage of 200~1000 nm. The transmittance of ZnO film increased with increasing the oxygen gas flow rate because of the transition from conduction band to oxygen interstitial band due to the oxygen interstitial (Oi) sites. The low reflectance and the high transmittance of ZnO film was suitable properties to use for the front electrode in the display or solar cell.