• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.6
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• pp.342-346
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• 2004

A thermopneumatic-actuated polydimethylsiloxane (PDMS) micropump has been fabricated and their properties are characterized. The diffusers are used as a flow-rectifying element instead of passive check valves. The advantages of the proposed microvalve are of the low cost fabrication process and the transparent optical property using PDMS and indium tin oxide (ITO) glass. We presented the PDMS micropump that is easily integrated with the in-channel PDMS microvalves on the same substrate. The flowrate of the micropump increases linearly as the applied pulse voltage to the ITO heater increases. The fabricated ITO heater resistance is 6.54k$\Omega$. The peak of the flow rate is observed at the duty ratio of 10% for the applied pulse voltage of 55V at 6Hz and the maximum flow rate of 78nl/min is measured.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.71-74
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• 1989

The $\alpha$-Fe$_2$O$_3$ gas sensor, prepared by the precipitation of Fe(OH)$_3$ from a solution of iron(III) sulfate and tin (IV) chloride, was composed of fine particles and was superior in sensitivity to other $\alpha$-Fe$_2$O$_3$. The gas sensitivity was found to depend on the amounts of remaining sulfate ion the microstructure and a small amount of iron(II) species generated through the reduction of $\alpha$-Fe$_2$O$_3$. The sensing mechanism of $\alpha$-Fe$_2$O$_3$gas sensor was confirmed to be due to the reduction of $\alpha$-Fe$_2$O$_3$ to the low resistive Fe$_3$-xO$_4$ by combustible gas and to depend on the crystral structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.137-140
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• 2001

To improve structural properties and induce higher conductivity, we have annealed emitting layer, The temperature condition was investigated by various experiment. To observe the surface morphology of emitting layer, measured the AFM and the X-ray diffraction pattern of P3HT film is shown. It is move to slightly low angles and diffraction peaks also become much sharper. After annealing of emitting layer, EL intensity and Voltage-current-luminance curve is better as compared with untreated. But PL intensity was decreased. It is known that by emission principal. After annealing of emitting layer, EL devices enhances the interface adhesion between the emissive polymer and Indium-tin-oxide electrode, which takes a critical role to improve the emitting properties of EL devices.

• Journal of the Korean institute of surface engineering
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• v.50 no.2
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• pp.55-71
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• 2017

Transparent Conductive Oxide (TCO), especially Indium Tin Oxide (ITO) films are almost prepared by DC magnetron sputtering because of the advantage of obtaining homogeneous large area coatings with high reproducibility. The purpose of this report is describe a detailed investigation of key factors dominating electrical and structural properties of sputtered ITO films. It was confirmed that crystallinity and electrical properties of ITO films were strongly depend on the sputtering pressure and kinetic energy of sputtered particles which are expected to have a close relation with the transport processes between target and substrate. And also, nodule formation on the ITO target was suppressed by both $CaCO_3$ addition and decreasing micro-pore in the target. On the other hand, we focused on the characteristics of amorphous TCO film to use as transparent electrode for various applications. To realize high thermoelectric performance, it was tried to control both high electrical conductivity and low thermal conductivity for the amorphous IZO:Sn films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.396-396
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• 2007

We investigated the liquid crystal (LC) aligning capabilities and electrooptical characteristics of semi-transparent silver paste electrodes substituting indium tin oxide (ITO) electrodes. Experimental results show that a uniform vertical LC alignment and a large pretilt angle were achieved using the semi-transparent silver paste. The vertical alignment mode based on the semi-transparent silver paste electrodes showed appropriate electro-optical characteristics and a high transparency in comparison with that based on the ITO electrodes. These results indicate that the semi-transparent silver paste electrodes of liquid crystal displays could substitute the ITO electrodes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.404-405
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• 2007

Tin-doped indium thin film is outstanding material among transparent Conductive Oxide (TCO) materials. ITO thin films show a low electrical resistance(<$10^{-4}\;[{\Omega}{\cdot}m]$) and high transmittance(>80%) in the visible range. ITO thin films usually have been deposited on the glass substrate. In order to apply flexible display, the substrate should have the ability to bend and be deposited without substrate heat. Also properties of ITO thin film depend on what kind of substrate. In this study, we prepared ITO thin film on the polycarbonate (PC) substrate by using Facing Target Sputtering (FTS) system. Before deposition of ITO thin film, PC substrate took plasma surface treatment. The electrical and surface properties of as-deposited thin films were investigated by Hall Effect measurement, UV/VIS spectrometer and the surface property of substrate is investigated by Contact angle measurement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.11
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• pp.922-927
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• 2001

Single-layer green ELs was fabricated with using molecularly-dispersed Bu-PBD into poly-N-vinylcarbazole(PVK) which has low operating voltage and high quantum efficiency. A EL cell structure of glass substrate/indium-tin-oxide/PVK:Bu-PBD:C6(∼ 100nm)/Ca(20nm)/Al(20nm) was employed with variable doping concentration. The keys to obtain high quantum efficiency was excellent film forming capability of molecularly dispersed into PVK and appropriate combination of cathode for avoiding exciplex. We obtained the turn-on voltage of 4.2V and quantum efficiency of 0.52% at 0.lmol% of C6 concentration which has been improved about a factor of 50 in comparison with the undoped cell. The PL peak wavelengths wouldn\`t be turned by changing the concentration of the C6 dopant. Green EL emission peak and FWHM were 520nm and 70nm respectively. PL emission peak was obtained at 495nm.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.57-57
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• 2010

Self assembled $Zn_{x-1}Cd_xS$ nanowires, synthesized on a Indium tin oxide coated glass substrate with low composition of Cd as x=0.09, were fabricated non-precursor via a co-evaporation method using of solid sources of CdS and ZnS. We studies that ZnCdS nanowires are dislocation-free and the single crystalline hexagonal wurtzite structure showed by transmission electron microscopy and selected area electron diffraction pattern. Cathode luminescence spectra showed an near band edge peak at 383nm originated from nanowires at 80K and 300K. Core level spectra of the Cd 3d, Zn 2p and S 2p in the ZnCdS nanorods were obtained by x-ray photoelectron spectroscopy. Prepared ZnCdS nanorods showed different shape with increase of substrate temperature at the growth.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.314.1-314.1
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• 2013

Transparent conducting nanoscale-domes were periodically patterned on a Si substrate by nanoimprint method. Transparent conductor of indium-tin-oxide (ITO) was shaped as a nanodome, which effectively drives the incident light effectively into a light-absorber and therefore induces a substantially enhanced photo-response. An ITO nanodome is electrically isolated from the neighboring nanodomes. This structure benefits to provide a low contact between a Si substrate and a front metal electrode giving an efficient electrical path. The ITO nanodome device showed a significantly enhanced photo-response of 6010 from the value of 72.9 of a planar ITO film. The electrical and optical advantage of an ITO nanodome is suitable for various photoelectric applications.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.120-123
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• 2019

The effect of surface plasmon on ZTO thin films was investigated. The phenomenon of depletion occurring in the interface of the ZTO thin film created a potential barrier and the dielectric layer of the depletion formed a non-mass particle called plasmon. ZTO thin film represents n-type semiconductor features, and surface current by plasma has been able to obtain the effect of improving electrical efficiency as a result of high current at positive voltage and low current at negative voltage. It can be seen that the reduction of electric charge due to recombination of electronic hole pairs by heat treatment of compound semiconductors induces higher surface current in semiconductor devices.