• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1023-1028
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• 2004

RF magnetron sputtering을 이용하여 증착한 투명전도성 ZnO 박막의 F 도핑량에 따른 전기, 구조, 광학적 특성에 대해 고찰하였다. 순수 ZnO와 ZnO : $ZnF_2$(1.3 wt%) 그리고 ZnO : $ZnF_2$(10 wt%) 3개의 타겟들을 2개씩 조합 각각의 rf 파워를 조절하여 co-sputtering 방법으로 $ZnF_2$ wt%를 변화시켜 박막내의 F 도핑량을 조절하였다. 증착된 박막들은 열처리에 따른 물성 변화를 분석하기 위해 $5{\times}10^{-7}$ torr 이하의 진공 분위기에서 $300^{\circ}C$에서 2 시간 동안 열처리하였다. XRD 분석 결과 제작된 모든 ZnO 박막은 (002) 우선 방위 특성을 보였고 F 도핑량 증가에 따라 (101), (110), (100) 방향의 약한 피크들이 나타났으며, 이러한 구조적 특성 변화는 이동도의 변화와 밀접한 관계가 있는 것으로 나타났다. Auger로 박막 내의 F 량을 분석한 결과 최대 5.9 at%의 F이 포함되어 있었으며, 열처리 후 캐리어 농도와 이동도는 증가하였고 최고 $37cm^2/Vs$의 이동도를 나타내었으며, 모든 박막들은 가시광 영역에서 81 % 이상의 투과도를 가졌다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 추계학술발표대회
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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).

• 한국응용과학기술학회지
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• 제29권4호
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• pp.626-630
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• 2012

Diagnosis with an ex-vivo gold sensor was done using a modified fluorine-doping sensor, and cyclic voltammetry (CV) redox potentials of 0.4 V anodic and -0.2 V cathodic were obtained. Both peak currents were optimized using square-wave (SW) stripping voltammetry, and an analytical working range of 10-80 ug/L SW was attained. The precision of the 10-mg/L Au was 0.765 (n=8) RSD under the optimum conditions, and the analytical detection limit approached 0.006 ug/L (S/N=3) with only a 60 sec accumulation time. The developed method was used to examine the mouse droppings for medicinal diagnosis.

• Journal of Magnetics
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• 제17권3호
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• pp.163-167
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• 2012

The effects on the ferromagnetism of the O or Zn defect in Cu-doped ZnO with the concentration of 2.77-8.33% have been investigated by the first-principles calculations. The Cu doping in ZnO was calculated to be a kind of p-type ferromagnetic half-metals. When the Zn vacancy exists in Cu-doped ZnO, the Cu magnetic moment increases, while for the O vacancy it is reduced. It is noticeable that the ferromagnetic state was originated from the hybridized O(2p)-Cu(3d)-O(2p) chain formed through the p-d coupling. The carrier-mediated ferromagnetism by nitrogen or fluorine does not depend on their concentration.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.335-335
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• 2014

Over the past several years, transparent conducting oxides have been extensively studied in order to replace indium tin oxide (ITO). Here we report on fluorine doped zinc tin oxide (FZTO) films deposited on glass substrates by radio-frequency (RF) magnetron sputtering using a 30 wt% ZnO with 70 wt% SnO2 ceramic targets. The F-doping was carried out by introducing a mixed gas of pure Ar, CF4, and O2 forming gas into the sputtering chamber while sputtering ZTO target. Annealing temperature affects the structural, electrical and optical properties of FZTO thin films. All the as-deposited FZTO films grown at room temperature are found to be amorphous because of the immiscibility of SnO2 and ZnO. Even after the as-deposited FZTO films were annealed from $300{\sim}500^{\circ}C$, there were no significant changes. However, when the sample is annealed temperature up to $600^{\circ}C$, two distinct diffraction peaks appear in XRD spectra at $2{\Theta}=34.0^{\circ}$ and $52.02^{\circ}$, respectively, which correspond to the (101) and (211) planes of rutile phase SnO2. FZTO thin film annealed at $600^{\circ}C$ resulted in decrease of resistivity $5.47{\times}10^{-3}{\Omega}cm$, carrier concentration ~1019 cm-3, mobility~20 cm2 V-1s-1 and increase of optical band gap from 3.41 to 3.60 eV with increasing the annealing temperatures and well explained by Burstein-Moss effect. Change of work function with the annealing temperature was obtained by ultraviolet photoemission spectroscopy. The increase of annealing temperature leads to increase of work function from ${\phi}=3.80eV$ (as-deposited FZTO) to ${\phi}=4.10eV$ ($600^{\circ}C$ annealed FZTO) which are quite smaller than 4.62 eV for Al-ZnO and 4.74 eV for SnO2. Through X-ray photoelectron spectroscopy, incorporation of F atoms was found at around the binding energy of 684.28 eV in the as-deposited and annealed FZTO up to 400oC, but can't be observed in the annealed FZTO at 500oC. This result indicates that F atoms in FZTO films are loosely bound or probably located in the interstitial sites instead of substitutional sites and thus easily diffused into the vacuum from the films by thermal annealing. The optical transmittance of FZTO films was higher than 80% in all specimens and 2-3% higher than ZTO films. FZTO is a possible potential transparent conducting oxide (TCO) alternative for application in optoelectronics.

• E2M - 전기 전자와 첨단 소재
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• 제9권4호
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• pp.404-409
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• 1996

The structural and electric properties of $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$(x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) have been investigated by using XRD(X-ray diffraction), TMA(thennomechanical analysis), NMR(nuclear magnetic resonance) analysis and four probe method. $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$ samples were prepared by conventional solid-state reaction method using $Y_{2}$O$_{3}$, BaCO$_{3}$, CuO and YbF$_{3}$ power. TMA and high temperature XRD results shows that orthorhombic to tetragonal phase transition occurs in the unfluorinated 1-2-3 sample while the phase change is not observed in the fluorinated 1-2-3 samples. Superconducting transition temperature(T$_{c}$) increases with increasing YbF$_{3}$ content ; T$_{c}$, of the sample reaching maximum of 102K for x=0.3, and then decreases with further increasing YbF$_{3}$ content. The structural analysis and T$_{c}$ results shows that the fluorine doping stabilize the orthorhombic phase, together with the increase in T$_{c}$.}$ c/.TEX> c/.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.55.2-55.2
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• 2009

A polymer electrolyte membrane (PEM) fuel cell has been getting large interest as a typical issue in useful applications. The PEMFC is composed of a membrane, catalyst and the bipolar plate. SnOx:F films on SUS316 stainless steel were prepared as a function of substrate with using electron cyclotron resonance-metal organic chemical vapor deposition (ECR-MOCVD) in order to achieve the corrosion-resistant and low contact resistance bipolar plates for PEM fuel cells. The SnOx:F films coated on SUS316 substrate at surface plasma treatment for excellent stability, before/after heat treatment for good crystalline structure and microwave power for were characterized by X-ray diffraction (XRD), auger electron microscopy (AES) and field emission-scanning electron microscopy (FE-SEM). The SnOx:F film coated on SUS316 substrate with various process parameters were able to observe optimum interfacial contact resistance (ICR) and corrosion resistance. It can be concluded that fluorine-doping content plays an important function in electrical property and characteristic of corrosion-protective film.

• 공업화학
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• 제21권1호
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• pp.29-33
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• 2010

본 연구에서는 여러 가지 열처리 온도에서 다성분 도핑에 의한 광촉매의 밴드갭 저감 및 가시광 광분해 효과를 알아보고자 tetraethylammonium tetrafluoroborate (TEATFB)로 B, C, N, F 등이 동시에 도핑된 $TiO_{2}$ 광촉매를 제조하였다. 도핑된 $TiO_{2}$ 광촉매가 가시광선영역에서 분해되는 정도를 확인하기 위해서 태양광에 조사하여 rhodamine B와 acridine orange로 염료분해 실험을 수행하였다. XRD 결과 $800^{\circ}C$ 이하에서 열처리된 $TiO_{2}$ 광촉매는 anatase 구조가 존재하고 있음을 알 수 있었다. XPS 분석을 통하여 광활성에 영향을 미치는 B, C, N, F의 결합구조를 확인하였고 UV-DRS 결과로부터 다성분 도핑된 $TiO_{2}$ 광촉매의 밴드 갭이 2.98 eV로 줄어든 것을 알 수 있었다. 다성분 도핑 $TiO_{2}$의 태양광 조사에 의한 UV-Vis 결과에서 acridine orange에 대한 광분해 효과가 도핑되지 않은 샘플에 비해 1.61배 증가함을 알 수 있었다. 특히, 다성분이 동시 도핑되고 $700^{\circ}C$에서 열처리된 샘플이 acridine orange과 rhodamine B 두 가지 염료 모두에서 가장 좋은 광분해 효과를 보여 주었다.