• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.749-751
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• 2002

$(Pb_{1-x}Sr_x)TiO_3$ $(0.6{\leq}x{\leq}0.8)$ thin films were prepared by the MOD method for tunable microwave device application and their characteristics were investigated as a function of Sr content(x) and applied field. Thin films showed a homogeneous microstructure and the tetragonality(c/a) was slightly decreased with increasing Sr content. With increasing Sr content, Curie temperature of the thin films showed a decreasing tendency. For the PST thin films, the dielectric constant at room temperature, Tc, and $tan{\delta}$ were 750~1900, $-70^{\circ}{\sim}-30^{\circ}C$ and 0.025~0.04, respectively.

• Current Optics and Photonics
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• 제2권1호
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• pp.96-100
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• 2018

A tunable low-phase-noise microwave generation structure that utilizes an optoelectronic oscillator (OEO) and a fiber Bragg grating (FBG) is proposed and experimentally demonstrated in this article. This structure has no particular requirement for the band width of the laser, and its tunability is realized through adjusting the central frequency of the tunable FBG. A detailed theoretical analysis is established and confirmed via an experiment. A high-purity microwave signal with a frequency tunable from 6 to 12 GHz is generated. The single-sideband phase noise of the generated signal at 10.2 GHz is -117.2 dBc/Hz, at a frequency offset of 10 kHz.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.1047-1052
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• 2003

Controlling carrier transport in light emitting polymers is extremely important for their efficient use in organic opto-electronic devices [1]. Here we show that the interactions between single wall carbon nanotubes (SWNTs) and conjugated polymers can be used to modify the overall mobility of charge carriers within nanotube-polymer nanocomposites. By using a unique, double emitting-organic light emitting diodes (DE-OLEDs) structure. we have characterized the hole transport within electroluminescent nanocomposites (nanotubes in poly (m-phenylene vinylene-co-2,5-dioctoxy-p-phenylene) or PmPV). We have shown using this idea that single devices with color tunability can be fabricated. It is seen that SWNTs in PmPV are responsible for hole trapping, leading to shifts in the emission wavelengths. Our results could lead to improved organic optical amplifiers, semiconducting devices, and displays.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.685-688
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• 2003

[ $(Ba,Sr,Ca)TiO_3$ ] powders, prepared by the sol-gel method, were mixed with an organic vehicle and the BSCT thick films were fabricated by the screen printing techniques on alumina substrates. The grain size decreased with increasing amounts of $MnO_2$, and the BSCT(50/40/10) thick film doped with 1wt% $MnO_2$ showed a value of 6.5mm. The thickness of thick films by four-cycle on printing/drying was approximately 100mm. The relative dielectric constant, dielectric loss and tunability of the BSCT(S0/40/10) thick films doped with 1.0wt% $MnO_2$ were 1296, 0.61% and 11.18%, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.632-635
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• 2003

[ $(Ba,Sr,Ca)TiO_3$ ] powders, prepared by the sol-gel method, were mixed with organic vehicle and the BSCT thick films were fabricated by the screen printing techniques on alumina substrates. The dielectric properties were investigated for various composition ratio and $Nb_2O_5$ doping contents. All the BSCT thick films, sintered at $1420^{\circ}C$, showed the typical XRD patterns of a perovskite polycrystalline structure. The Curie temperature and the relative dielectric constant decreased with increasing Ca content and $Nb_2O_5$ doping amount. The relative dielectric constant, dielectric loss and tunability of the BSCT(50/40/10) thick films doped with 1.0wt% $Nb_2O_5$ were 1410, 0.65% and 17.29% respectively.

• Journal of Electrochemical Science and Technology
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• 제3권2호
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• pp.68-71
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• 2012

The electrospinning technique is a revolutionary template-catalyst-free method that can generate 1D nanostructure with the tunability and the potential for the mass production. This approach received a great deal of attention due to its ability to give direct pathways for electrical current and has been utilized in various electronic applications. However, the delamination of inorganic electrospun film has prevented the intense utilization due to the thermal expansion/contraction during the calcination. In this study, we propose an electrical grounding method for transparent conducting oxide and electrospun nanowires to enhance the adhesion after the calcination. Then, we examined the potential of the technique on ZnO based dye-sensitized solar cells.

• 한국광학회지
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• 제14권1호
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• pp.8-11
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• 2003

기계적으로 유도된 소자형 장주기 광섬유격자를 처음으로 제작해 보았다. 본 연구의 장주기 광섬유격자 소자는 제작이 용이하며. 다른 광 소자나 시스템에 적용 또는 장착이 가능하다는 장점을 가지고 있다. 또한, 제작된 장주기 광섬유격자 소자는 격자 제작시 중심파장과 투과손실을 가변할 수 있는 특징을 가지고 있다. 장주기 광섬유격자 소자의 제작원리를 살펴보고, 제작된 장주기 광섬유격자의 파장가변 특성과 압력에 따른 투과특성을 실험해 보았으며, 장주기 광섬유격자 소자를 EDFA의 이득 평탄화 실험에 적용해 보았다.

• 산업기술연구
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• 제26권A호
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• pp.95-99
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• 2006

In this paper, we proposed the new wavelength tunable filter for wide tunability of fiber ring laser. The proposed filter consists of the cascaded connection of Fiber Reflection Mach-Zehnder Interferometer and Sagnac filter or of hybrid filter and Fiber Reflection Mach-Zehnder Interferometer. The simulation shows that the continuous tunable range of 50nm can be obtained and that more stable single mode operation of ring laser can be expected due to narrow FWHM. of filter spectrum.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.261-261
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• 2010

Photonic band gap (PBG) materials have been of great interest due to their potential applications in science and technology. Their applications can be further extended when PBG becomes tunable against various chemical and electrical stimuli. In recent, it was found that tunable photonic band gap materials can be achieved by incorporating stimuli-responsive smart gels into PBG materials. For example, the characteristic volume phase transition of gels in response to the various external stimuli including temperature, pH, ionic strength, solvent compositions and electric field were recently combined with the unique optical properties of photonic crystals to form unprecedented highly responsive optical components. Since these responsive photonic crystals are capable of reversibly converting chemical or electrical energy into characteristic optical signals, they have been considered as a good platform for label-free chemical or biological detection, actuators or optical switches as well as a model system for investigating gel swelling behavior. Herein, we report block copolymer photonic gels self-assembled from polystyrene-b-poly (2-vinyl pyridine) (PS-b-P2VP) block copolymers. In this talk, we are going to demonstrate that selective swelling of lamellar structure can be effectively utilized for fabricating PBG materials with extremely large tunability. Optical properties and their applications will be discussed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.22-23
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• 2011

As device dimensions shrink, it is increasingly important to develop fabrication methods that can create sub-15 nm features of regular or arbitrary geometry in a rapid, parallel, and efficient process. This talk will discuss approaches based on self-assembling hybrid polymers containing Si. The thin films of those materials systems can generate well-ordered periodic arrays of dots or lines. For achieving, long-range ordering, it is helpful to use lithographically-defined templates, which are in general much larger than the length-scale of self-assembled nanostructures. For example, the self-assembly of polymer nanostructures can easily be templated using an array of nanoscale topographical elements that act as guiding templates or surrogates for one of two microdomains. The solvent-vapor-induced tunability of pattern dimension and morphology will be discussed as well. Those material systems can excellently serve for high-precision self-assembly that can provide good resolution, reliability, and controllability and be considered as an option for a future nanomanufacturing technology.