• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.453.1-453.1
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• 2014

Fluorine-doped tin oxide (FTO), which is commonly used in dye-sensitized solar cells (DSSCs), is a promising material of transparent conducting oxides (TCOs) because of advantages such as high chemical stability, high resistance, high optical transparency (>80% at 550nm), and low electrical resistivity (${\sim}10-4{\Omega}{\cdot}cm$). Especially, dye-sensitized solar cells (DSSCs) have been actively studied since Gratzel's research group required FTO substrate as a charge collector. When FTO substrates are used in DSSCs, photo-injected electrons may experience recombination at interface between dye-bonded semiconductor oxides ($TiO_2$) on FTO substrate and the electrolyte. To solve these problems, one is that because recombination at FTO substrate cannot be neglected, thin $TiO_2$ layer on FTO substrate as a blocking layer was introduced. The other is to control the morphology of surface on FTO substrate to reduce a loss of electrons. The structural, electrical, and optical characteristics of morphology controlled-FTO thin films as TCO materials were analyzed by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Hall Effect Measurement, and UV spectrophotometer. The performance of DSSCs fabricated with morphology controlled FTO substrates was performed using Power Conversion Efficiency (PCE). We will discuss these results in detail in Conference.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.50.1-50.1
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• 2009

Transparent conductive oxides (TCOs) play an important role in thin-film solar cells in terms of low cost and performance improvement. Al-doped ZnO (AZO) is a very promising material for thin-film solar cellfabrication because of the wide availability of its constituent raw materials and its low cost. In this study, AZO films were prepared by low pressurechemical vapor deposition (LPCVD) using trimethylaluminum (TMA), diethylzinc(DEZ), and water vapor. In order to improve the absorbance of light, atypical surface texturing method is wet etching of front electrode using chemical solution. Alternatively, LPCVD can create a rough surface during deposition. This "self-texturing" is a very useful technique, which can eliminate additional chemical texturing process. The introduction of a TMA doping source has a strong influence on resistivity and the diffusion of light in a wide wavelength range.The haze factor of AZO up to a value of 43 % at 600 nm was achieved without an additional surface texturing process by simple TMA doping. The use of AZO TCO resulted in energy conversion efficiencies of 7.7 % when it was applied to thep-i-n a-Si:H thin film solar cell, which was comparable to commercially available fluorine doped tin oxide ($SnO_2$:F).

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1482-1484
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• 2002

Transparent conductive oxides (TCO) are necessary as front electrode for most thin film solar cell. In our paper, transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Corning 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCI (0.5%) to examine the electrical and surface morphology properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure and the substrate temperature. In low pressures (0.9mTorr) and high substrate temperatures $({\leq}300^{\circ}C)$, the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.128-128
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• 2003

Electrochromism (EC) is defined as a phenomenon in which a change in color takes place in the presence of an applied voltage. Because of their low power consumption, high coloration efficiency, EC devices have a variety of potential applications in smart windows, mirror, and optical switching devices. An EC devices generally consist of a transparent conducting layer, electrochromic cathodic and anodic coloring materials and an ion conducting electrolyte. EC has been widely studied in transition metal oxides(e.g., WO$_3$, NiO, V$_2$O$\sub$5/) Among these materials, WO$_3$ is a most interesting material for cathodic coloration materials due to its lush coloration efficiency (CE), large dynamic range, cyclic reversibility, and low cost material. WO$_3$ films have been prepared by a variety of methods including vacuum evaporation, chemical vapor deposition, electrodeposition process, sol-gel synthesis, sputtering, and laser ablation. Sol-gel process is widely used for oxide film at low temperature in atmosphere and requires lower capital investment to deposit large area coating compared to vacuum deposition process.

• Korean Journal of Materials Research
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• v.31 no.3
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• pp.150-155
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• 2021

Zinc oxide (ZnO) based transparent conducting oxides (TCO) thin films, are used in many applications such as solar cells, flat panel displays, and LEDs due to their wide bandgap nature and excellent electrical properties. In the present work, fluorine and aluminium-doped ZnO targets are prepared and thin films are deposited on soda-lime glass substrate using a RF magnetron sputtering unit. The aluminium concentration is fixed at 2 wt%, and the fluorine concentration is adjusted between 0 to 2.0 wt% with five different concentrations, namely, Al2ZnO98(AZO), F0.5AZO97.5(FAZO1), F1AZO97(FAZO2), F1.5AZO96.5(FAZO3), and F2AZO96(FAZO4). Thin films are deposited with an RF power of 40 W and working pressure of 5 m Torr at 270 ℃. The morphological analysis performed for the thin film reveals that surface roughness decreases in FAZO1 and FAZO2 samples when doped with a small amount of fluorine. Further, optical and electrical properties measured for FAZO1 sample show average optical transmissions of over 89 % in the visible region and 82.5 % in the infrared region, followed by low resistivity and sheet resistance of 3.59 × 10-4 Ωcm and 5.52 Ω/sq, respectively. In future, these thin films with excellent optoelectronic properties can be used for thin-film solar cell and other optoelectronics applications.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.200-201
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• 2002

투명 전도막은 높은 광 투과도와 전기 전도도를 동시에 가지는 물질로서 TFT-LCD, 태양 전지 등 다양한 산업에 응용되고 있다(1). 투명 전도막 중에서 가장 많이 사용되는 물질은 In$_2$O$_3$에 Sn을 첨가한 인듐 주석 산화물(ITO)이나 투명 전도막 응용 산업의 발전에 따라 더 높은 광 투과도와 전기 전도도, 우수한 에칭 특성 및 매끄러운 표면 상태를 동시에 가지면서 저온 제작이 가능하여 ITO의 성질을 능가하는 우수한 신규 투명 전도막 개발이 요구되고 있다. (중략)

• Journal of the Korean Society for Heat Treatment
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• v.29 no.2
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• pp.62-65
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• 2016

TIO thin films were deposited on the poly-carbonate substrates with RF magnetron sputtering under different sputtering power condition to investigate the influence of deposition rate on the electrical and optical properties of the films. Although, all films have the similar carrier concentration, the films prepared at a lower deposition rate of 4 nm/min show a higher mobility of $5.96cm^2\;V^{-1}S^{-1}$ due to the low surface roughness. In addition, optical transmittance is also influenced by a deposition rate. Based on the figure of merit, it can be concluded that the lower deposition rate effectively enhances the opto-electrical performance of IGZO films for use as transparent conducting oxides in flexible display applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.108-108
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• 2009

ITO에 사용되는 주된 재료인 인듐의 bixbyite 구조는 TCOs의 전기적 특성에서 매우 중요한 것으로 알려져 있다. 때문에 인듐의 Bixbyite구조를 유지하면서 인듐의 사용량을 줄이기 위해 최적의 Solubility limit에 관해 연구하였다. 이를 위해 In2O3-ZnO-SnO2의 삼성분계 기본 조성에 두가지 물질을 추가로 첨가하여 첨가량에 따른 Solubility limit을 연구하였다. Solubility limit의 측정을 위해 X-ray Diffractometer(XRD)를 사용하였으며, 첨가 원소의 양이 증가할수록 TCOs target의 Latice parameter값은 작아졌다, SEM을 통한 미세구조의 관찰로 원소첨가에 따른 샘플의 소결에너지 변화를 분석할 수 있었다. 제작된 시편의 정성분석 및 Chemical binding Energy를 측정하기 위해 X-ray Photo Spectroscopy (XPS)를 이용하였으며, 전기적인 특성 측정을위해 4-Point prove mesurement 방법을 사용하였다.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.319-322
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• 1989

Using pyrosol method, based on the pyrolysis of an aerosol produced by ultrasonic spraying, the deposition of transparent conducting oxides (TCO) such as $In_2O_3$ : Sn, $SnO_2$ : Sb and $SnO_2$ : F on glass substrates was studied. The electrical, optical and structural properties as functions of substrate temperature, dopant concentration, substrate type and carrier gas type were investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.307-308
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• 2008

Zinc oxide is a direct band gap wurtzite-type semiconductor with band gap energy of 3.37eV at room temperature. the n-type doped ZnO oxides, B doped ZnO (BZO) is widely studied in TCOs materials as it shows good electrical, optical, and luminescent properties. we focused on the fabrication of B doped ZnO films with glass substrate using the LSMCD at low temperature. And Novel boron-doped ZnO thin films were deposited and characterized from the structural, optical, electrical point of view. The structure, morphology, and optical properties of the films were studied as a function of by employing the XRD, SEM, Hall system and micro Raman system.