• 한국정보통신학회논문지
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• 제13권1호
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• pp.115-120
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• 2009

PLD 법으로 3 wt.% Al이 도핑된 ZnO 타겟을 이용하여 corning 1737 기판위에 200 mTorr의 고정된 산소 분압에서 기판온도 ($100\;{\sim}\;250^{\circ}C$)에 따른 AZO 박막의 구조적, 광학적, 전기적 특성을 조사하였다. 모든 박막들은 c 축 배향되었으며, 오직 (002) 회절 피크만 관찰되었다. $250^{\circ}C$에서 제작한 AZO 박막에서 가장 우수한 (002) 배향성을 보였으며, 이때의 반가폭 값은 $0.44^{\circ}$ 였다. 모든 박막이 가시광 영역에서 85 % 이상의 투과율을 보였으며, Burstein-Moss 효과가 관찰되었다. 전기적 특성은 $250^{\circ}C$에서 제작한 박막에서 가장 우수한 캐리어 농도 ($3.48{\times}10^{20}cm^{-3}$)와 비저항 ($1.65{\times}10^{-2}{\Omega}cm$) 값을 나타냈다.

• 한국재료학회지
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• 제31권3호
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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.

• 한국전기전자재료학회논문지
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• 제37권2호
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• pp.169-174
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• 2024

In this study, the structural, electrical, and optical properties of AZO films of various thicknesses are compared. The AZO films were deposited on a glass substrate by FTS (Facing-Target-Sputtering) This research was conducted to find the optimal thickness for Transparent Conductive Oxide (TCO). AZO has suitable properties for TCO such as low resistivity, and high transmittance. Thin films of all thicknesses showed a transmittance of over 80% in the visible light region and electrical properties improved as thickness increased. It was confirmed that the film of 300 nm thick had the best performance due to its low resistivity, and uniform surface. This research is expected to help find optimal conditions in various fields where TCO is used, such as solar cells, displays, and sensors in the future.

• 전기학회논문지
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• 제65권10호
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• pp.1702-1705
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• 2016

We propose a novel hydrogen-reduced p-type amorphous silicon oxide buffer layer between $TiO_2$ antireflection layer and p-type silicon window layer of silicon thin film solar cells. This new buffer layer can protect underlying the $TiO_2$ by suppressing hydrogen plasma, which could be made by excluding $H_2$ gas introduction during plasma deposition. Amorphous silicon oxide thin film solar cells with employing the new buffer layer exhibited better conversion efficiency (8.10 %) compared with the standard cell (7.88 %) without the buffer layer. This new buffer layer can be processed in the same p-chamber with in-situ mode before depositing main p-type amorphous silicon oxide window layer. Comparing with state-of-the-art buffer layer of AZO/p-nc-SiOx:H, our new buffer layer can be processed with cost-effective, much simple process based on similar device performances.

• 산업융합연구
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• 제20권12호
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• pp.79-85
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• 2022

최근 전자소자는 플렉서블 기판상에 제작된 스마트폰이 출시되었으며, 스트레처블 한 전자소자의 연구가 진행되고 있다. 본 논문에서는 실리콘 기반의 스트레처블한 소재를 만들어 이것을 기판으로 사용하여 산화물을 이용한 광센서 소자를 구현하여 평가하고자 한다. 이를 위해, 실리콘 기반의 용액성 고무를 이용하여 상온에서 잘 늘어나는 기판을 만들어 소재의 350% 연신율을 확인하였으며, 반사도, 투과도, 흡수도와 같은 광특성을 측정하였다. 다음으로 이러한 소재는 표면이 소수성을 나타내기 때문에 표면 세정 및 친수성으로 변화시키기 위하여 산소 기반의 플라즈마 표면 처리를 진행하였으며, 진공장비로 AZO(Aluminium Zinc Oxide) 기반의 산화막을 증착한 후 면봉을 이용하거나 메탈 마스트로 Ag 전극을 형성시켜 광센서를 완성하였다. 제작된 광전자소자는 빛을 조사했을 때와 하지 않았을 때의 전압에 따른 전류 변화를 분석하여 광에 의하여 생성된 캐리어들에 의한 광전류를 관찰하였으며, 벤딩 장비를 이용하여 폴딩에 따른 광센서소자 영향성을 추가 테스트하였다. 벤딩 테스트 전과 빛에 의해 생성되는 전류값 변화를 추가로 분석하였다. 향후 스트레처블 기판위에 늘어나는 반도체 물질 및 전극을 형성하여 폴딩(벤딩) 및 늘어나는 광소자를 집중적으로 연구할 계획이다.

• 반도체디스플레이기술학회지
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• 제9권3호
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• pp.23-27
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• 2010

We prepared Al doped ZnO thin film as a top electrode on a glass substrate with a deposited $Alq_3$ for the top emission organic Light emitting device (TEOLED) with facing target sputtering (FTS) method and radio-frequency (RF) sputtering method, respectively. Before the deposition of AZO thin film, we evaporated the $Alq_3$ on glass substrate by thermal evaporation. And we evaluated the damage of organic layer. As a result, PL intensity of $Alq_3$ on grown by FTS method showed higher than that of grown by RF sputtering method, so we found that the FTS showed the lower damage sputtering than RF sputtering. Therefore, we can expect the FTS method is promising the low-damage sputtering system that can be used as a direct sputtering on the organic layer.

• 한국세라믹학회지
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• 제32권7호
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• pp.799-808
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• 1995

Transparent conductive films of aluminium doped zinc oxide (AZO) have been prepared by using the DC magnetron sputtering with the ZnO : Al (Al2O3 2 wt%) oxide target oriented to c-axis. Electrical and optical properties depended upon the O2/Ar gas ratio. The optical transmittance and sheet resistance of the AZO coated glass was 60~65% and 75Ω/$\square$, respectively at the O2/Ar gas ratio of 0. With the increase of the oxygen partial pressure to 2.0$\times$10-2, they were increased to the values of 81% and 1kΩ/$\square$, respectively. The films with the resistivities of 1.2~1.4$\times$10-3 Ω.cm, mobilities of 11~13 $\textrm{cm}^2$/V.sec and carrier concentrations of 3.5$\times$1020~4.0$\times$1020/㎤ were produced at the optimum O2/Ar gas ratio, which was 0.5$\times$10-2~1.0$\times$10-2. According to XRD analysis, the films have only one peak corresponding to the (002) plane, which indicates that there is a strong preferred orientation of the films. The grain size of ZnO films were calculated to 200~320 $\AA$, which was increased with the O2/Ar gas ratio and Ar gas flowrate.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.447-447
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• 2009

In this study, transparent and conductive Al-doped zinc oxide (AZO) films were prepared on Corning glass and silicon wafer substrate by RF magnetron sputtering method using an Al-doped ZnO target (Al: 2 wt.%) at room temperature as the thickness of 150 nm. We investigated the effects of the RF power between 100 Wand 350 W in steps of 50 W on structural, electrical and optical properties of AZO films. Also, we studied the effects of the working pressure (3, 4 and 5 mtorr) on that condition. The thickness and cross-sectional images of films were observed by field emission scanning electron microscopy (FE-SEM) and all of the films were kept to be constant to $150\pm10$ nm on Coming glass and silicon wafer. A grain size was calculated from X-ray diffraction (XRD) on using the Scherrer' equation and their electrical properties investigated hall effect electronic transport measurement system. Moreover, we measured transmittance of AZO films by UV/VIS spectrometer.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.77.1-77.1
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• 2012

Zn 기반 산화물 반도체는 기존의 비정질 Si에 비해 저온공정에도 불구하고 높은 이동도, 투명하다는 장점으로 인해 차세대 디스플레이용 백플레인 소자로 주목받고 있다. 산화물 트랜지스터는 우수한 소자특성을 보여주고 있지만, 온도, 빛, 그리고 게이트 바이어스 스트레스에 의한 문턱전압의 불안정성이 문제의 문제를 해결해야한다. 산화물 반도체의 문턱전압의 불안정성은 유전체와 채널층의 계면 혹은 채널에서의 charge trap, photo-generated carrier, ads-/desorption of molecular 등의 원인으로 보고되고 있어, 고신뢰성의 산화물 채널층을 성장하기 위한 노력이 이루어지고 있다. 최근, 산화물 트랜지스터의 다양한 조건에서의 문턱전압의 불안정성을 해결하기 위해 산화물의 주된 결함으로 일컬어지고 있는 산소결핍을 억제하기 위해 성장공정의 제어 그리고, 산소와의 높은 binding energy를 같은 Al, Hf, Si 등과 같은 원소를 첨가하여 향상된 소자의 특성이 보고되고 있지만, 줄어든 산소공공으로 인해 이동도가 저하되는 문제점이 야기되고 있다. 이러한 문제점을 해결하기 위해, 최근에는 Buried layer의 삽입 혹은 bi-channel 등과 같은 방안들이 제안되고 있다. 본 연구는 atomic layer deposition을 이용하여 AZO bureid layer가 적용된 ZnO 트랜지스터의 특성과 안정성에 대한 연구를 하였다. 다결정 ZnO 채널은 유전체와의 계면에 많은 interface trap density로 인해 positive gate bias stress에 의한 문턱전압의 불안정성을 보였지만, AZO층이 적용된 ZnO 트랜지스터는 줄어든 interface trap density로 인해 향산된 stability를 보였다.

• Current Photovoltaic Research
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• 제5권4호
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• pp.135-139
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• 2017

We fabricated two different transparent conducting oxide thin films of ZnO doped with Ga ($Ga_2O_3$ 0.9 wt%) as well as Al ($Al_2O_3$ 2.1 wt%) (GAZO) and ZnO doped only with Al ($Al_2O_3$ 3 wt%) (AZO). It was investigated how it affects the moisture resistance of the transparent electrode. In addition, $Cu(In,Ga)Se_2$ thin film solar cells with two transparent oxides as front electrodes were fabricated, and the correlation between humidity resistance of transparent electrodes and device performance of solar cells was examined. When both transparent electrodes were exposed to high temperature distilled water, they showed a rapid increase in sheet resistance and a decrease in the fill factor of the solar cell. However, AZO showed a drastic decrease in efficiency at the beginning of exposure, while GAZO showed that the deterioration of efficiency occurred over a long period of time and that the long term moisture resistance of GAZO was better.