• 센서학회지
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• 제24권6호
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• pp.364-367
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• 2015

Tin oxide thin films were fabricated on glass substrates by the successive ionic layer adsorption and reaction (SILAR) method at room temperature and ambient pressure. Before measuring their properties, all samples were annealed at $500^{\circ}C$ for 2 h in air. Film thickness increased with the number of cycles; X-ray diffraction patterns for the annealed $SnO_2$ thin films indicated a $SnO_2$ single phase. Thickness of the $SnO_2$ films increased from 12 to 50 nm as the number of cycles increased from 20 to 60. Although the optical transmittance decreased with thickness, 50 nm $SnO_2$ thin films exhibited a high value of more than 85%. Regarding electronic properties, sheet resistance of the films decreased as thickness increased; however, the measured resistivity of the thin film was nearly constant with thickness ($3{\times}10^{-4}ohm/cm$). From Hall measurements, the 50 nm thickness $SnO_2$ thin film had the highest mobility of the samples ($8.6cm^2/(V{\cdot}s)$). In conclusion, optical and electronic properties of $SnO_2$ thin films could be controlled by adjusting the number of SILAR cycles.

• 한국정보전자통신기술학회논문지
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• 제12권3호
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• pp.218-223
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• 2019

높은 CVD 그래핀저항으로 인한 낮은 발열효과를 해결하기 위해 다층으로 그래핀을 적층하여, 저저항의 광학특성이 우수한 투명 면상 발열시스템을 구현하였다. 제작한 CVD 그래핀의 발열필름으로 $300{\times}400{\times}5mm$ 발열체를 제작하고, 효율적인 전력을 구동하기 위해 PWM 제어를 통한 회로를 구성하여 시스템을 구현하였다. 발열체로 사용한 4층의 CVD 그래핀 필름의 평균 면 저항 측정값은 $85.5{\Omega}/sq$이다. 따라서 저 저항의 CVD 그래핀의 구현 방법으로 열전사의 적층의 방법은 타당하다. 발열시험 결과, CVD 그래핀을 이용한 저저항 투명 면상 발열 시스템의 평균 발열상승은 $10^{\circ}C/min$ 이고, 86.44%의 CVD 그래핀 필름의 광투과율을 갖음을 보여준다. 따라서 제시한 발열 시스템은 대형창 유리 및 자동차 발열유리로서 적용가능하다.

• 한국표면공학회지
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• 제34권5호
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• pp.503-509
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• 2001

Thin films of hydrogenated amorphous silicon (a-Si : H) and hydrogenated amorphous silicon carbide (a-SiC:H) of different compositions were deposited on Si(100) wafer and glass by RF plasma-enhanced chemical vapor deposition (RF-PECVD). In the present work, we have investigated the effects of the RF power on the properties, such as optical band gap, transmittance and crystallinity. The Raman data show that the a-Si:H material consists of an amorphous and crystalline phase for the co-presence of two peaks centered at 480 and $520 cm^{-1}$ . The UV-VIS data suggested that the optical energy band gap ($E_{g}$ ) is not changed effectively with RF power and the obtained $E_{g}$(1.80eV) of the $\mu$c-Si:H thin film has almost the same value of a-Si:H thin film (1.75eV), indicating that the crystallity of hydrogenated amorphous silicon thin film can mainly not affected to their optical properties. However, the experimental results have shown that$ E_{g}$ of the a-SiC:H thin films changed little on the annealing temperature while $E_{g}$ increased with the RF power. The Raman spectrum of the a-SiC:H thin films annealed at high temperatures showed that graphitization of carbon clusters and microcrystalline silicon occurs.

• 한국진공학회지
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• 제22권3호
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• pp.119-125
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• 2013

In-line magnetron sputtering system을 사용하여 대면적($60{\times}60cm^2$) 소다라임 유리기판위에 투명전도성 ZnO(Al)와 ZnO(AlGa) 박막을 500 nm에서 1,450 nm까지 두께별로 증착하여 전기적, 광학적 특성을 연구하였다. XRD를 통해 c-축 방향성(002)을 가지고 성장된 것을 확인 하였다. Hall 특성 분석을 통해 이동도 및 캐리어 농도의 특성을 확인 하였으며, 그에 따른 ZnO(AlGa)의 비저항이 $9.03{\times}10^{-4}{\Omega}{\cdot}cm$에서 $7.83{\times}10^{-4}{\Omega}{\cdot}cm$으로 ZnO(Al) 보다 높게 나타났으며, 가시광선 영역에서 투과율은 87.6%에서 84.3%으로 나타났다. 따라서 ZnO(AlGa)는 전기적 특성이 우수하고 높은 투과율로 대면적용 투명전도성 재료로의 활용에 적합한 특성을 지닌 것을 확인 할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1738-1740
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• 1999

This paper deals with a novel structure of poly-Si solar cell. A solar cell conversion efficiency was degraded by grain boundary effect in Polycrystalline silicon. To reduce grain boundary effect, we performed a preferential grain boundary etching, $POCl_3$ n-type emitter doping, and then ITO film growth on poly-Si. Among the various preferential etchants, Schimmel etch solution exhibited the best result having grain boundary etch depth about $10{\mu}m$. RF magnetron sputter grown ITO films showed a low resistivity of $10^{-4}\Omega-cm$ and high transmittance of 85%. With well fabricated poly-Si solar cells. we were able to achieve as high as 15% conversion efficiency at the input power of 20mW/$cm^2$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.425-425
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• 2008

The transparent conducting oxides(TCOs) are widely used as electrodes for most flat panel display devices(FPDs), electrodes in solar cells and organic light emitting diodes(OLED). Among them, indium oxide materials are mostly used due to its high electrical conductivity and a high transmittance in the visible spectrum. The present study reports on a study of the electrical and optical properties of IGZO thin films prepared on glass and PET substrates by the combinational magnetron sputtering. We use the targets of IZO and Ga2O3 for the deposition process. In some case the deposition process is coupled with the End-Hall ion-beam treatment onto the substrates before the sputtering. In addition we control the deposition rate to optimize the film quality and to minimize the surface roughness. Then we investigate the effects of the Ar gas pressure and RF power during the sputtering process upon the electrical, optical and morphological properties of thin films. The properties of prepared IGZO thin films have been analyzed by using the XRD, AFM, a-step, 4-point probe, and UV spectrophotometer.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2002년도 추계학술대회 발표 논문집
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• pp.85-90
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• 2002

$RuO_2$/GaN and related contacts were investigated for Schottky contacts in GaN-Based optical and electronic devices. We demonstrated that an $RuO_2$ film forms a stable Schottky contact on a GaN layer with a barrier height (${\Phi}_B$) of 1.46 eV and transmittance of 70% in the visible and near UV region. $RuO_2$/GaN Schottky diode showed a breakdown at over -50V and leakage current of only 0.3 nA at -5V. The $RuO_2$/GaN Schottky type photodetector had the UV/Visible rejection ratio of over $10^5$ and the responsivity of 0.23 A/W at 330 nm. The $RuO_2$ gate AlGaN/GaN EFET exhibited high drain current ($I_d$) of 689.3 mA/mm and high transconductance ($g_m$) of 197.4 mS/mm. Cut-Off frequency ($f_t$) and maximum operating frequency ($f_{max}$) were measured as 27.0 GHz and 45.5 GHz, respectively.

• 대한금속재료학회지
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• 제50권7호
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• pp.545-548
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• 2012

The optical and electronic properties of Indium Tin Oxide (ITO) thin films deposited on a RF-plasma treated glass substrate were investigated by X-Ray Photoelectron Spectroscopy (XPS), Ultra-violet Photoelectron Spectroscopy (UPS), Reflected Electron Energy Loss Spectroscopy (REELS). The modification of glass substrates was carried out by varying the time of the plasma surface treatment in an oxygen atmosphere. The focus of this research was to examine how the optical and electronic properties of ITO thin films change with the plasma treatment time. The surface energy increased since the carbon bonds were removed from the surface after the glass substrate received the surface treatment. The ITO thin films produced on the glass substrate with surface treatment showed that the high optical transmittance was approximately 85%. The measured band gap energy was as high as 3.23 eV when the plasma treatment time was 60 s and the work function after the treatment was increased by 0.5 eV in comparison to that before the treatment of 60 s. The ITO thin film exhibited an excellent sheet resistance of $2.79{\Omega}/{\Box}$. We found that the optical and electronic properties of ITO thin films can be improved by RF-plasma surface treatment.

• ETRI Journal
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• 제45권6호
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• pp.1056-1064
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• 2023

The optical properties of the materials composing organic light-emitting diodes (OLEDs) are considered when designing the optical structure of OLEDs. Optical design is related to the optical properties, such as the efficiency, emission spectra, and color coordinates of OLED devices because of the microcavity effect in top-emitting OLEDs. In this study, the properties of top-emitting blue OLEDs were optimized by adjusting the thicknesses of the thin metal layer and capping layer (CPL). Deep blue emission was achieved in an OLED structure with a second cavity length, even when the transmittance of the thin metal layer was high. The thin metal film thickness ranges applicable to OLEDs with a second microcavity structure are wide. Instead, the thickness of the thin metal layer determines the optimized thickness of the CPL for high efficiency. A thinner metal layer means that higher efficiency can be obtained in OLED devices with a second microcavity structure. In addition, OLEDs with a thinner metal layer showed less color change as a function of the viewing angle.

• 한국전기전자재료학회논문지
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• 제33권1호
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• pp.25-30
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• 2020

Oxide (SiO₂)/Metal(Ag)/Oxide(SiO₂, ITO, ZnO) multilayer films were fabricated using a magnetron sputtering technique at room temperature on Si (p-type, 100) and a glass substrate. The electrical and optical properties of the asymmetric multilayer films depended on the thickness of the mid-layer film and the type of oxide in the bottom layer. As the metal layer becomes thicker, the sheet resistance decreases. However, the transmittance decreases when the metal layer exceeds a threshold thickness of approximately 10~12 nm. In addition, the sheet resistance and transmittance change according to the type of oxide in the bottom layer. If the oxide has a large resistivity, the overall sheet resistance increases. In addition, the anti-reflection effect changes according to the refractive index of the oxide material. The optical and electrical properties of multilayer films were investigated using an ultraviolet visible (UV-Vis) spectrophotometer and a 4-point probe, respectively. The optimum structure is SiO₂ (30 nm)/Ag (10 nm)/ZnO (30 nm) multilayer, with the highest FOM value of 7.7×10^-3 Ω^-1.