• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.287-290
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• 1998

It was investigated that the dielectric properties of ferroelectric materials using PZT-5A and PZT thin films. PZT-5A was 20mm diameters, 0.71mm, 0.51mm and 0.41mm thickness respectively and having c-axis preferred orientation. Electrodes(Al) were deposited by evaporation method. PZT thin film was deposited on Pt/SiO$_2$/Si substrate by RF magnetron sputtering method, and annealed at 750$^{\circ}C$ with RTA. Dielectric constants were measured automatically by computer measuring system. Dielectric constants were changed rapidly from 817 to 888 in 0.41mm thickness PZT-5A, 823 to 890 in 0.51mm and 822 to 839 in 0.71mm as the electric field grown. In the case of PZT thin film, dielectric constants were changed from 724 to 1173 in 4500${\AA}$ thickness, 721 to 1204 in 5500${\AA}$ thickness and 811 to 1407 in 7000${\AA}$ thickness.

• Korean Journal of Materials Research
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• v.16 no.5
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• pp.292-296
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• 2006

Effects of rapid thermal annealing of bismuth telluride thin films on their thermoelectric properties were investigated. Films with four different compositions were elaborated by co-sputtering of Bi and Te targets. Rapid thermal treatments in range of $300{\sim}400^{\circ}C$ were carried out during 10 minutes under the reducing atmosphere (Ar with 10% $H_2$). As the temperature of thermal treatment increased, carrier concentrations of films decreased while their mobilities increased. These changes were clearly observed for the films close to the stoichiometric composition. Rapid thermal treatment was found to be effective in improving the thermoelectric properties of $Bi_2Te_3$ films. Recrystallization of $Bi_2Te_3$ phase has caused the enhancement of thermoelectric properties, along with the decrease of the carrier concentration. Maximum values of Seebeck coefficient and power factor were obtained for the films treated at $400^{\circ}C$ (about $-128{\mu}V/K$ and $9{\times}10^{-4}\;W/K^2m$, respectively). With further higher temperature ($500^{\circ}C$), thermoelectric properties deteriorated due to the evaporation of Te element and subsequent disruption of film's structure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.9
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• pp.701-706
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• 2013

We have focused on the conversion efficiency of CIGS thin film solar cell prepared by co-evaporation method as well as the optimization of process condition. The total thickness of back electrode was fixed at 1 ${\mu}m$ and the structural, electric and optical properties of CIGS thin film were investigated by varying the thickness of Mo:Na bottom layer from 0 to 500 nm. From the experimental results, the content of Na was appeared as 0.28 atomic percent when the thickness of Mo:Na layer was 300 nm with compactly densified plate-shape surface morphology. From the XRD measurements, (112) plane was the strongest preferential orientation together with secondary (220) and (204) planes affecting to the crystallization. The lowest roughness and resistivity were 2.67 nm and 3.9 ${\Omega}{\cdot}cm$, respectively. In addition, very high carrier density and hole mobility were recorded. From the optimization of Mo:Na layer, we have achieved the conversion efficiency of 9.59 percent.

• Journal of Sensor Science and Technology
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• v.14 no.4
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• pp.258-264
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• 2005

Li+-ion conducting ($Li_{3}PO_{4}$) thin films with thickness of $0.3{\mu}m$, $0.65{\mu}$, $1.2{\mu}$ were deposited on $Al_{2}O_{3}$ substrate at room temperature by thermal evaporation. They were sintered at $700^{\circ}C$ and $800^{\circ}C$ for 2 hours, respectively. Reference electrode and sensing electrode were printed on Au-electrode by silk printing method. The EMF and the ${\Delta}EMF$/dec were increased with increasing the electrolyte thickness and sintering temperature. The sample sintered at $800^{\circ}C$ was shown a good response and recovery characteristics more than those sintered at $700^{\circ}C$. The Nernst's slop of 75 mV per decade was obtained at operating temperature of $500^{\circ}C$.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1999.06a
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• pp.115-127
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• 1999

The charged clusters or particles, which contain hundreds to thousands of atoms or even more, are suggested to form in the gas phase in the thin film processes such as CVD, thermal evaporation, laser ablation, and flame deposition. All of these processes are also used in the gas phase synthesis of the nanoparticles. Ion-induced or photo-induced nucleation is the main mechanism for the formation of these nanoclusters or nanoparticles inthe gas phase. Charged clusters can make a dense film because of its self-organizing characteristics while neutral ones make a porous skeletal structure because of its Brownian coagulation. The charged cluster model can successfully explain the unusual phenomenon of simultaneous deposition and etching taking place in diamond and silicon CVD processes. It also provides a new interpretation on the selective deposition on a conducting material in the CVDd process. The epitaxial sticking of the charged clusters on the growing surface is gettign difficult as the cluster size increases, resulting in the nanostructure such as cauliflowr or granular structures.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.289-294
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• 1999

The charged clusters or particles, which contain hundreds to thousands of atoms or even more, are suggested to from in the gas phase in the thin film processes such as CVD, thermal evaporation, laser ablation, and flame deposition. All of these processes are also phase synthesis of the nanoparticels. Ion-induced or photo-induced nucleation is the main mechanism for the formation of these nanoclusters or nanoparticles in the gas phase. Charge clusters can make a dense film because of its self-organizing characteristics while neutral ones make a porous skeletal structure because of its Brownian coagulation. The charged cluster model can successfully explain the unusual phenomenon of simultaneous deposition and etching taking place in diamond and silicon CVD processes. It also provides a new interpretation on the selective deposition on a conducting material in the CVD process. The epitaxial sticking of the charged clusters on the growing surface is getting difficult as the cluster size increases, resulting in the nanostructure such as cauliflower or granular structures.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.6
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• pp.582-589
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• 1991

We used Cd Se as the semiconductor to analyze the Poly-TFT. Cd Se TFT is fabricated by the vacuum evaporation method and the characteristics curves of the current-voltage are obtained using the results of measurement of Cd Se TFT devices. Employing least square method and Rosenbrock algorithm, we can extract the device parameters(grain boundary mobility, trap density). The current-voltage relations calculated by extracted parameters are in good agreement with experimental results.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.179-179
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• 2009

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1119-1120
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• 2007

Nano-sized metal patterns were successfully fabricated on flexible PET substrate using nanoimprint lithography. 70nm line and space PMMA resist pattern was formed on PET substrate without residual layer by 'artial filling effect' and 20nm thin Cr metal layer was deposited by e-beam evaporation. Then, PMMA resist was selectively removed by acetone and 70nm narrow Cr pattern was formed.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.152.1-152
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• 1998