• Journal of Electrochemical Science and Technology
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• 제2권4호
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• pp.204-210
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• 2011

Thin film electrodes have been intensively studied for active materials and current collectors to enhance the electrochemical performance. Here, porous structures of nickel-based oxide films, consisting of nickel oxide and copper (II) oxide, which was derived from the copper substrate during the annealing process, were deposited on metallic copper foils. The half-cell tests revealed excellent capacity retention after $80^{th}$ charge/discharge cycles. Some films showed an excess of the theoretical capacity of nickel oxides, which mainly originate from partially oxidized copper substrates during annealing. These results exhibit that both a preparation method of an active materials and partially oxidized current collectors could be important roles to apply thin film electrodes.

• 한국진공학회지
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• 제8권2호
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• pp.127-135
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• 1999

Nickel oxide films were prepard by using the electron beam evaporation technique. Coloring and bleaching experiments for cyclic durability were repeated in KOH electrolyte by cyclic voltammetry. Visible spectrophtometry was used to assess the stability of the transmittance in the degraded films. X-ray photoelectron spectroscopy results showed that the grain surface are oxygen-rich compared to the grain interiors in a NiO film. Open circuit memory of colored films is about 400hours in lN KOH. The rate of self discharge was evaluated by measuring the transmittance at 550nm of a fully oxidized NiO film. The rate of self discharge was increased polynomially with time and the film is nearly bleached after about 400hours. It was also found that the degraded film by repeated cycles in the KOH solution changed the grain shape of film surface The film prepared under a vacuum pressure of $3\times10^{-4}$ mbar was found to be rather stable when subjected to the repeated coloring and bleaching cycles in KOH electrolyte. Band theory applied to explain the electrochromic mechanism was discussed.

• 대한화학회지
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• 제10권4호
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• pp.153-157
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• 1966

순수한 nickel의 酸化에 대하여 大氣中에서와 各種 酸素壓力下 $500^{\circ}{\sim}800^{\circ}C$에서 石英製 微量天秤을 使用하여 그 速度를 測定하였다. Nickel의 速度常數는 Parabolick rate Law에 의하여 계산하였다. 活性化 에너지는 Arrhenius式에 의하여 구하였으며 ${\Delta}E^*=35.4{\pm}$1.5 Kcal/mole을 얻었다. Nickel酸化에서 酸化速度常數는 酸素壓力의 1/4.93乘에 比例함을 확인하였고 Nickel의 酸化機構는 Oxide Film에 용해되어 과잉으로 存在하는 酸素에 의해서 形成된 陽이온 Vacancy (空位)에 依存한다는 結論에 도달하였다.

• 한국세라믹학회지
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• 제13권2호
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• pp.8-16
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• 1976

The conductive transparent film is prepared by spraying thin salt solution. In stannic chloride solution as a base solution, various dopants such as Al, Co, Cu and Ni were dissolved respectively as a chloride state and then the films were made by spraying solutions on hot glass plates. The properties of them were compared with those of the stannic salt single component film. The films doped with copper oxide and nickle oxide were improved by decreasing their sheet resistivity and temperature coefficient of resistivity. In comparison with the sheet resistivity and temperature coefficient of resistivity of stannic oxide single component film, being 2.5 K ohm/$\textrm{cm}^2$ and -1650ppm/$^{\circ}C$ respectively, its values of the film containing 15 mol % of copper oxide and formed at 40$0^{\circ}C$ were 2.5K ohm/$\textrm{cm}^2$ and -920ppm/$^{\circ}C$ respectively. The film containing 15 mol % of nickel oxide and formed at 50$0^{\circ}C$ has shown its sheet resistivity and temperature coefficient 0.7 K ohm/$\textrm{cm}^2$ and -940ppm/$^{\circ}C$ respectively.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.441-442
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• 2007

We deposited nickel oxide(NiO) thin films on silicon(Si) substrates at Room temperature and $500^{\circ}C$ using a nickel target by reactive DC and RF sputtering. In addition, we anneal to NiO thin films deposited at room temperature. Using spectroscopic eillipsometry, we obtained optical characteristics of every films. We discussed relations of the optical and structural properties of NiO thin films with the oxygen flow rate, substrate temperature and annealing temperatures. Refraction was decreased and defect was increased when NiO thin films was annealed. We also analyzed the electrical characteristics of NiO films which deposited DC and RF sputtering method.

• Current Photovoltaic Research
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• 제11권4호
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• pp.103-107
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• 2023

A Nickel oxide (NiO_x) thin films were prepared via sol-gel process on a transparent conductive oxide glass substrate. The NiO_x thin films were spin-coated in ambient air and subsequently annealed for 30 minutes at temperatures ranging from 150℃ to 450℃. The structural and optical characteristics of the NiO_x thin films annealed at various temperatures were measured using X-ray diffraction, field emission scanning electron microscopy, and ultraviolet-visible spectroscopy. After optimizing the NiO_x coating conditions, perovskite solar cells were fabricated with p-i-n inverted structure, and its photovoltaic performance was evaluated. NiO_x thin films annealed at 350℃ exhibited the most favorable characteristics as a hole transport layer, resulting in the highest power conversion efficiency of 17.88 % when fabricating inverted perovskite solar cells using this film.

• 한국세라믹학회지
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• 제38권8호
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• pp.683-686
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• 2001

Electrochemically active lithium nickel cobalt oxide thin-film was not fabricated until now. The thin-film was deposited by RF magnetron sputtering at room temperature, and its initial phase was amorphous. By varying deposition condition, the different characteristics of thin-film were achieved. Using electrochemical analyses, the relationship between physical and electrochemical characteristics was identified. Crystallized thin-film by RTA (Rapid Thermal Annealing) was shown a good capacity and cycle property.

• 한국표면공학회지
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• 제25권3호
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• pp.107-116
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• 1992

The optimum thickness of Pd-Ni plated layers used as an electrical contact film was investigated by evaluating mechanical, thermal and environmental characteristics. The variations of morphologies and chemical compositions were studied by using SEM, EDS and ESCA. As a result of wear test, the wear resistance behavior of the gold plated layers was not changed with the sliding velocity changes. The palladium-nickel plated layer showed better wear resistance than the gold plated layer at low sliding velocity, but it showed poor wear resistance at high sliding velocity. Under the thermal condition of $400^{\circ}C$ in air, the gold thickness of $2\mu\textrm{m}$ without underplate on phosphorous bronze formed copper oxide on the surface layer by rapid diffusion of copper whereas the gold thickness of $0.8\mu\textrm{m}$ deposited on nickel and palladium-nickel underplate was stable at $400^{\circ}C$. Under the sulfur dioxide environments, the gold thickness of $0.3\mu\textrm{m}$ deposited on the nickel thickness of$ 3\mu\textrm{m}$ and the palladium-nickel thickness of $2\mu\textrm{m}$ underplate was more corrosion-resistant than the gold thickness of $2\mu\textrm{m}$ without underplate on phosphorous bronze. Under the nitric acid vapor environment, corrosion resistance of the gold film was superior to an equivalent thickness of the palladium-nickel film.

• 반도체디스플레이기술학회지
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• 제7권1호
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• pp.29-34
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• 2008

In this paper, the DE(double erosion) cathode for the reactive magnetron sputtering system is developed for high deposition rate and high target utilization efficiency. The utilization efficiency of the developed DE cathode is 22% higher than that of normal SE(single erosion) cathode. Sputtering process for the nickel oxide thin films with the DE cathode is performed under the following conditions; power with $1kW{\sim}3kW$, pressure with 4mtorr and 8mtorr, oxygen flow ratio with $0%{\sim}80%$. As a result, the hysteresis phenomenon of discharge voltage in 4mtorr is lower than that in 8mtorr and the hysteresis phenomenon of discharge voltage is getting lower as the applied power is getting higher. The structure of cross section and surface roughness of the thin films are observed by FE-SEM and AFM. The structure of cross section of the thin films is columnar and the average surface roughness under oxygen flow ratio of 0%, 52.5% and 65.0% are $2.08{\AA}$, $2.20{\AA}$ and $0.854{\AA}$, respectively.

• 한국안광학회지
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• 제7권2호
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• pp.163-167
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• 2002

$Ni(OH)_2/Ni$ Glass 박막에서 전기변색 속도 개선에 대한 연구를 수행하였다. 이는 선글라스의 변색속도가 수분 이상 소요되는 단점을 해결하고자 e-beam evaporator를 이용하여 니켈 금속 박막을 증착시킨 후, 전기화학적 산화-환원 반응으로 $Ni(OH)_2$에 대한 전기변색 특성을 연구하였다. 전기전도성을 갖는 ITO 에서보다 Glass 위에서의 $Ni(OH)_2$의 변색 속도가 오히려 빠르다. 이는 전위와 투과율을 측정함으로서 알 수 있다. XPS를 이용하여 Glass와 $Ni(OH)_2$ 사이의 초박막(${\sim}10{\AA}$) Ni 금속의 존재를 확인하였고, 이 나노 박막은 전기변색 장치의 응답 속도에 영향을 마쳤다. 기존의 선글라스가 5분 정도 소요되는 반면 니켈 나노 박막을 이용한 변색소자에서는 1~2초 정도 소요된다. 이론적으로는 수 ms 이내이지만 전기적 저항으로 인해 초 단위의 응답속도를 보이고 있다.