• Journal of the Korean Chemical Society
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• v.65 no.2
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• pp.125-132
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• 2021

An electrochromic nickel oxide thin film was fabricated on a flexible PET/ITO substrate using a nanocrystallite- dispersed coating sol and bar coater. Nanocrystalline NiOx of 3-4 nm crystallite size was first synthesized by base precipitation and thermal conversion. This NiOx nanocrystallite powder was mechanically dispersed in an alcoholic solvent mixed with a silane binder to prepare a coating sol for thin film. This sol method is different from the normal sol-gel method in that it does not require the conversion of precursor by heat treatment. Therefore, this method provides a very facile method to prepare NiOx thin films on any kind of substrate and it can be easily applied to mass production. The electrochromic performance of this NiOx thin film on PET/ITO electrode with a thickness of about 400 nm was investigated in a nonaqueous LiClO4 electrolyte solution by cyclic voltammetric and repeated chronoamperometric measurements in conjunction with spectrophotometry. The visible light modulation of 44% and the colorization efficiency of 41 ㎠/C at 550 nm were obtained at the step potentials of -0.8/+1.2 V vs Ag and a duration of 30 s.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.2
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• pp.170-174
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• 2023

Nickel oxide is a nonstoichiometric transparent conductive oxide with p-type conductivity, a wide-band energy gap of 3.4~4.0 eV, and excellent chemical stability, making it a very important candidate as a material for bipolar devices. P-type conductivity in Transparent Conductive Oxides (TCO) is controlled by the oxygen vacancy concentration. During the TCO film deposition process, additional oxygen diffusing into the NiO structure causes the formation of Ni 3p ions and Ni vacancies. This eventually affects the hole concentration of the p-type oxide thin film. In this work, the surface morphology and the electrical characteristics were confirmed in accordance with the annealing atmosphere of the nickel oxide thin film.

• 한국전기화학회:학술대회논문집
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• 2000.04a
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• pp.30-30
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• 2000

• 한국전기화학회:학술대회논문집
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• 2000.10a
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• pp.36-36
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• 2000

• Proceedings of the Korean Magnestics Society Conference
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• 2002.04a
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• pp.46-47
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• 2002

• Transactions of the Korean hydrogen and new energy society
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• v.10 no.4
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• pp.211-217
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• 1999

In order to investigate the possibilities of microbatteries using TiNi type metal hydride, TiNi films were prepared by DC magnetron sputtering. The films were deposited under various Ar flow rates, DC powers and target-to-substrate distances to find the optimum sputtering conditions. The deposition rate of TiNi thin film increased by increasing the DC power and by decreasing the Ar flow rate and target-to-substrate distance. The chemical composition of the film changed as a target-to-substrate distance. The crystal structure of the film was amorphous state just after deposition and changed to crystalline by vacuum heat treatment.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.5
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• pp.245-248
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• 2010

Sn doped $In_2O_3$ (ITO) and ITO/Ni/ITO (INI) multilayer films were deposited on the glass substrates with a reactive magnetron sputtering system without intentional substrate heating and then the influence of the Ni interlayer on the methanol gas sensitivity of ITO and INI film sensors were investigated. Although both ITO and INI film sensors have the same thickness of 100 nm, INI sensors have a sandwich structure of ITO 50 nm/Ni 5 nm/ITO 45 nm. The changes in the gas sensitivity of the film sensors caused by methanol gas ranging from 100 to 1000 ppm were measured. It is observed that the INI film sensors show the higher sensitivity than that of the ITO single layer sensors. Finally, it can be concluded that the INI film sensor have the potential to be used as improved methanol gas sensors.

• Journal of the Korean Society for Heat Treatment
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• v.28 no.3
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• pp.121-125
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• 2015

GZO single layer, Ni buffered GZO(GZO/Ni), Ni intermediated GZO (GZO/Ni/GZO) and Ni capped GZO (Ni/GZO) films were prepared on poly-carbonate (PC) substrates by RF and DC magnetron sputtering without intentional substrate heating and then the influence of the Ni (2 nm thick) thin film on the optical, electrical and structural properties of GZO films were investigated. As deposited GZO single layer films show the optical transmittance of 81.3% in the visible wavelength region and a resistivity of $1.0{\times}10^{-2}{\Omega}cm$, while GZO/Ni/GZO trilayer films show a lower resistivity of $6.4{\times}10^{-4}{\Omega}cm$ and an optical transmittance of 74.5% in this study. Based on the figure of merit, it can be concluded that the intermediated Ni thin film effectively enhances the opto-electrical performance of GZO films for use as transparent conducting oxides in flexible display applications.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.83-88
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• 2018

The electromigration (EM) tests were performed at $150^{\circ}C$ with $1.5{\times}10^5A/cm^2$ conditions in order to investigate the effect of non-conductive film (NCF) trap on the electrical reliability of Cu/Ni/Sn-Ag microbumps. The EM failure time of Cu/Ni/Sn-Ag microbump with NCF trap was around 8 times shorter than Cu/Ni/Sn-Ag microbump without NCF trap. From systematic analysis on the electrical resistance and failed interfaces, the trapped NCF-induced voids at the Sn-Ag/Ni-Sn intermetallic compound interface lead to faster EM void growth and earlier open failure.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.5
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• pp.216-220
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• 2010

Ni-Fe alloys have various applications such as thin film inductor, thin film transformer, magnetic head's shield case, etc. Magnetic properties of Ni-Fe thin films depend on the process parameters such as thickness, contents, deposition rate, substrates, etc. In this study, NiFe films with a thickness of about 150nm were deposited on Si(100) wafer and $SiO_2$/Si(100) substrate at room temperature by a DC magnetron co-sputtering using Fe and Ni targets. Their phase formation and magnetic properties as a function of annealing temperature were investigated with XRD, FE-SEM and VSM. The assputtered films have BCC structure. With increasing annealing temperature, NiFe thin film for $SiO_2$/Si(100) substrate transformed completely from BCC to FCC phase above $500^{\circ}C$, but some BCC phase remained above $500^{\circ}C$ on Si(100) wafer. For samples annealed at $450^{\circ}C$, squareness ratio of NiFe thin film shows peak value and its saturation magnetization is around 0.0118 emu, which means that the optimum annealing temperature of NiFe thin film seems to be $450^{\circ}C$. The saturation magnetization of films decreased rapidly above the annealing temperature of $500^{\circ}C$ due to phase transformation from BCC to FCC phase.