• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.593-599
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• 2003

The nanoparticle magnetite of which diameter was about 3 nm was synthesized in a homogeneous aqueous solution without a template. The synthesized magnetite nanoparticle was easily oxidized to maghemite in an ambient condition. The magnetic properties of the ferrite nanoparticle show superparamagnetism at room temperature and its blocking temperature is around 93 K. Modifying the sequential adsorption method of metal bisphosphonate, we have prepared a multilayer thin film of the ferrite nanoparticle on planar substrates such as glass, quartz and Si wafer. In this multilayer the ferrite nanoparticle layer and an alkylbisphosphonate layer are alternately placed on the substrates by simple immersion in the solutions of the ferrite nanoparticle and 1, 10-decanediylbis (phosphonic acid) (DBPA), alternately. This is the first example, as far as we know, of nanoparticle/alkyl-bisphosphonate multilayer which is an analogy of metal bisphosphonate multilayer. UV-visible absorption and infrared reflection-absorption studies show that the growth of each layer is very systematic and the film is considerably optically transparent to visible light of 400-700 nm. Atomic force microscopic images of the film show that the surface morphology of the film follows that of the substrate in μm-scale image and the nanoparticle-terminated surface is differentiated from the DBPA-terminated one in nm-scale image. The magnetic properties of this ferrite/DBPA thin film are almost the same as those of the ferrite nanoparticle powder only.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1334-1338
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• 2006

In this work, indium tin oxide (ITO) thin film was fabricated by indium-tin-organic sol including ITO nanoparticle. ITO nanoparticle showed ultrafine size about 5 nm and (222) preferred crystal structure. Also, ITO sol-gel thin film showed good optical transmittance over 83% and electrical resistance less than $7\;{\times}\;10^3\;{\Omega}$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.917-923
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• 2005

In this paper, effect of catalytic configuration on the sensing properties of $SnO_2$ nanoparticle gas sensitive thick film was investigated. Two types of catalytic configuration, mono and binary, were made on the $SnO_2$ nanoparticle. In case of mono catalytic system, $3 wt\%$ Pd or Pt catalyst was doped onto the $SnO_2$ nanoparticle, respectively. In case of binary catalytic system, Pd and Pt was doped simultaneously with concentration ratio of 1:2 to 2:1 onto the $SnO_2$ nanoparticle. After doping, gas sensitive thick film was printed on alumina substrate and heat-treated at 450 to $600^{\circ}C$. Gas sensing properties was evaluated using 500 to 10,000 ppm $CH_4$ gas. As a result, gas sensitive thick film with binary catalytic system showed unstable phenomena that the gas sensitivity was changed according to aging time. In contrary, the mono catalytic system showed relatively stable phenomena despite of aging time. Especially, gas sensitive thick film doped with $3 wt\%$ Pt catalyst and heat-treated at $500^{\circ}C$ showed good sensing properties such as 0.57 of $R_{3500}/R_{1000}$ and very small variation within $3.5\%$ after aging for 5 hours, and response time was very short less than 20 seconds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.267-267
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• 2009

Solar cells with CIGS absorber layers have proven their suitability for high efficiency and stable low cost solar cells. We prepared and characterized particle based CIGS thin film using a non-vacuum processing. CIGS powder were obtained at $240^{\circ}C$ for 6 hours from the reaction of $CuCl_2$, $InCl_3$, $GaCl_3$, Se powder in solvent. The nanoparticle precursors were mixed with binder material. The CIGS thin film deposited on a sodalime glass. The CIGS thin film were identified to have a typical chalcopyrite tetragonal structure by using UV/Visible-spectroscopy, X-ray diffraction(XRD), Auger Electron Spectroscopy(AES), Scanning Electron Microscopy(SEM).

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.467-470
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• 2007

Ultrafine Indium tin oxide (ITO) nanoparticle was successfully fabricated by low temperature synthetic method (LTSM). Mean size of ITO nanoparticle is 5 nm, and uniformly dispersed with (222) orientated cubic structure. Using the nanoparticle, ITO thin film with good optical and electrical properties was fabricated by inkjet printing.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.96-98
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• 2009

This report summarizes our recent efforts to produce large-grained CIGS materials from porous nanoparticle thin films. In our approach, a $Cu_xSe$ nanoparticle colloid were first prepared by reacting a mixture of CuI in pyridine with $Na_2Se$ in methanol at reduced temperature. purified colloid was sprayed onto heated molybdenum-coated sodalime glass substrates to form thin film. After thermal processing of the thin film under a selenium ambient. $Cu_xSe$ colloid and thin film were characterized by scanning electron microscopy, x-ray diffraction. The optical(direct) band gap energy of $Cu_xSe$ thin films is 1.5 eV.

• Journal of Sensor Science and Technology
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• v.31 no.2
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• pp.90-95
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• 2022

The effect of the structure of an ITO nanoparticle film sensor on its performance was studied. A printed ITO film (P-ITO film) was fabricated on a flexible polyethylene terephthalate (PET) substrate, and the contact resistance of the electrode and sensor response change were clarified according to the detection position. The contact resistance between Ag and P-ITO was observed to be -204.4 Ω using the transmission line method (TLM), confirming that a very good ohmic contact is possible. In addition, we confirmed that the contact position of the analyte had a significant influence on the response of the sensor. Based on these results, the performance of the four types of sensors was compared. Consequently, we observed that 1) optimizing the resistance of the printed film, 2) optimizing the electrode structure and analyte input position, and 3) optimizing the electrode area are very important for fabricating a metal oxide nanoparticle (MONP) sensor with optimal performance.

• Korean Journal of Materials Research
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• v.30 no.12
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• pp.701-708
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• 2020

Irradiation of the metal nanoparticles causes local plasmon resonance in a specific wavelength band, which can improve the absorption and scattering properties of a structure. Since noble metal nanoparticles have better resonance effects than those of other metals, it is easy to identify plasmonic reactions and this is advantageous to find the optical tendency. Compared to having a particle gap or randomly arranged particle structures, densely and evenly packed structures can exhibit more uniform optical properties. Using the uniform properties, the structure can be applied to optical filtering applications. Therefore, in this paper, validation tests about metal nanoparticles and thin film structures are conducted for more accurate analysis. The optical properties of monolayer and bilayer noble metal nanoparticle structures with different diameters, packed in a uniform array, are investigated and their optical trends are analyzed. In addition, a thin film structure under identical conditions as metal nanoparticle structure is evaluated to confirm the improved optical characteristics.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1067-1072
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• 2014

In this study, we report a new approach for $Mn_3O_4$-graphene nanocomposite by ex situ method. This nanocomposite shows two-dimensional aggregation of nanoparticle, and doping effect by decorated manganese oxide ($Mn_3O_4$), as well. The graphene film was made through micromechanical cleavage of graphite on the $SiO_2/Si$ wafer. Manganese oxide ($Mn_3O_4$) nanoparticle with uniform cubic shape and size (about $5.47{\pm}0.61$ nm sized) was synthesized through the thermal decomposition of manganese(II) acetate, in the presence of oleic acid and oleylamine. The nanocomposite was obtained by self-assembly of nanoparticles on graphene film, using hydrophobic interaction. After heat treatment, the decorated nanoparticles have island structure, with one-layer thickness by two-dimensional aggregations of particles, to minimize the surface potential of each particle. The doping effect of $Mn_3O_4$ nanoparticle was investigated with Raman spectra. Given the upshift in positions of G and 2D in raman peaks, we suggest that $Mn_3O_4$ nanoparticles induce p-doping of graphene film.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.1
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• pp.41-44
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• 2014

We employed UV-Ozone treatment method for the fabrication of dense and highly conductive nanoparticle thin films. We demonstrated the UV-Ozone treatment effect on the silver nanoparticle thin films as a function of time and temperature. The capping layers of nanoparticles were decomposed after UV-Ozone treatment and dense nanoparticle thin films were obtained. Moreover, electrical and mechanical properties of the thin films after UV-Ozone treatment were measured by using resistance measurements under tension in an in-situ tensile tester. The initial resistance of nanoparticle thin films was decreased by 82.6% with optimized UV-Ozone treatment condition of $150^{\circ}C$ for 20 minutes.