• Journal of Sensor Science and Technology
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• v.8 no.2
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• pp.177-183
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• 1999

A Polymer material, PU-BCN and a low molar mass material D-BCN with the same chromophore were evaluated by fabricating various electroluminescent(EL) devices. A molecular structure of the chromophore was composed as two cyano groups for electron-injection and transport and two triphenylamine groups for hole-injection and transport. Various kinds of EL devices with two different types of EL materials, PU-BCN and D-BCN were fabricated, which were an Indium-tin oxide(ITO)/PU-BCN or D-BCN/MgAg device as a single-layer device(SL) and an ITO/PU-BCN or D-BCN/oxadiazole ferivative/MgAg as a double-layer device(DL-E) and an ITO/triphenylamine derivative/D-BCN/MgAg as a double-layer device(DL-H) device. Two kinds of materials, PU-BCN and D-BCN showed the same emission characteristics in the high current density and excellent EL characteristics even in the SL devices. Maximum EL peaks revealed red emission of about 640 nm, which were corresponded with the fluorescence peaks of the films of two materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.255-255
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• 2013

최근 그래핀 연구와 더불어 2차원 구조의 나노소재에 대한 관심이 급증하면서 육각형의 질화붕소(hexagonal boron nitride; h-BN) 박막(nanosheet)이나 붕소 탄화질화물(boron caronitride; BCN) 박막과 같은 2차원 구조체에 대한 연구가 활발히 진행되고 있다. 그 중 BCN은 반금속(semimetal)인 흑연(graphite)과 절연체인 h-BN이 결합된 박막으로 원소의 구성 비율에 따라 전기적 특성을 제어할 수 있다는 장점이 있다. 따라서 다양한 나노소자로의 응용을 위한 연구가 활발히 진행되고 있다. 본 연구에서는 폴리스틸렌(polystyrene, PS)과 보레인 암모니아(borane ammonia)를 고체 소스로 이용하여 열화학 기상증착법을 이용하여 BCN 박막를 SiO2 기판 위에 직접 합성하였다. SEM과 AFM 관측을 통해 합성된 BCN 박막을 확인하였으며, RMS roughness가 0.5~2.6 nm로 매우 낮은 것을 확인하였다. 합성과정에서 PS의 양을 조절하여 BCN 박막의 탄소의 밀도를 성공적으로 제어하였으며, 이에 따라 전기적인 특성이 제어되는 양상을 확인하였다. 또한 합성온도 변화에 따른 BCN 박막의 전기적인 특성이 제어되는 양상을 확인하였다. 추가적으로 같은 방법을 이용하여 BCN 박막을 Ni 위에서 합성하여 SiO2 기판위에 전사 하였다. 합성된 BCN 박막의 구조적 특징과 화학적 조성 및 결합 상태를 투과전자현미경(transmission electron microscopy), X-선 광전자 분광법(X-ray photoelectron spectroscopy)을 통해 조사하였다.

• Journal of Surface Science and Engineering
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• v.36 no.3
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• pp.229-233
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• 2003

Boron-Carbon-Nitrogen (B-C-N) system is an attractive ternary material since it has not only an extremely high hardness but also a number of other prominent characteristics such as chemical inertness, elevated melting point, and low thermal expansion. In this paper, the corrosion behavior of B-C-N thin films in aqueous solution was investigated B-C-N films with different composition were deposited on a platinum plate by magnetron sputtering in the thickness range of 150-280 nm. In order to understand effect of pH of solutions, $BC_{2.\;4}N$ samples were immerged in 1M HCl, 1M NaCl, and 1M NaOH solution at 298k, respectively. BCN samples with different carbon contents were exposed to 1M NaOH solutions to investigate effect of chemical composition on corrosion resistance. Corrosion rates of samples were measured by ellipsometry, From results, optical constant of $BC_{2,\;4}N$ films was found to be $N_2=2.110-0.295i$. The corrosion rates of $Bi_{1.\;0}C_{2.\;4}N_{1.\;0}$ films were NaOH>NaCl>HCl in orders. With increasing carbon content in B-C-N films, the corrosion resistance of B-C-N films was enhanced. The lowest corrosion rate was obtained for $B_{1.\;0}C_{4.\;4}N_{1.\;9}$ film.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.33.1-33.1
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• 2010

BiFeO3 (BFO)는 강자성과 유전체 특성을 모두 구현할 수 있는 재료로서 연구가 활발히 진행되고 있다. BFO 박막을 제조하는 방법에는 sputtering, chemical solution deposition, pulsed laser deposition methods 등이 알려져 있으나, 이러한 방법들은 근본적으로 고 진공을 사용하거나, 고온에서의 열처리, 낮은 성막 속도 등의 문제점이 있어, 상온에서 비교적 쉽게 박막을 제조할 수 있는 Aerosol deposition에 관한 관심이 증가하고 있다. 본 연구에서는 BFO의 강자성, 강유전 특성을 향상시키기 위해 Ba(Cu1/3Nb2/3)O3 (BCN)를 첨가한 Ba(Cu1/3Nb2/3)O3 (BFO-BCN) 복합재료를 합성하였다. 합성한 마이크론 크기의 입자를 사용하여 나노 결정립 크기의 Ba(Cu1/3Nb2/3)O3 (BFO-BCN) 박막을 상온에서 진공 분말 분사 공정(Aerosol-Deposition)을 이용하여 제조하고, 강자성 및 강유전성 특성을 평가하였다. Aerosol deposition방법으로 제조된 BFO-BCN박막은 BFO박막에 비해 우수한 강자성과 강유전 특성 나타내었다.

• Transactions on Electrical and Electronic Materials
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• v.8 no.2
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• pp.84-88
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• 2007

[ $Bi_{1.5}Zn_{1.0}Nb_{1.5}O_7$ ] (BZN), $Bi_2Mg_{2/3}Nb_{4/3}O_7$ (BMN), and $Bi_2Cu_{2/3}Nb_{4/3}O_7$ (BCN) pyrochlore thin films were prepared on $Cu/Ti/SiO_2/Si$ substrates by pulsed laser deposition and the micro-structural and electrical properties were characterized for embedded capacitor applications. The BZN, BMN, and BCN films deposited at $25\;^{\circ}C$ and $150\;^{\circ}C$, respectively show smooth surface morphologies and dielectric constants of about $39\;{\sim}\;58$. The high dielectric loss of the films deposited at $150\;^{\circ}C$ compared with films deposited at $25\;^{\circ}C$ was attributed to the defects existing at interface between the films and copper electrode by an oxidation of copper bottom electrode. The leakage current densities and breakdown voltages in 200 nm thick-BMN and BZN films deposited at $150\;^{\circ}C$ are approximately $2.5\;{\times}\;10^{-8}\;A/cm^2$ at 3 V and above 10 V, respectively. Both BZN and BMN films are considered to be suitable materials for embedded capacitor applications.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.30.1-30.1
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• 2011

Multiferroic thin films with composition $0.9BiFeO_3-0.1Ba(Cu_{1/3}Nb_{2/3})O_3$ were epitaxially grown by pulsed laser deposition on $SrRuO_3(001)/SrTiO_3$ (000) substrate $0.9BiFeO_3-0.1Ba(Cu_{1/3}Nb_{2/3})O_3$, which is assumed to be morphotropic phase boundary (MPB), that showed superior dielectric, ferroelectric and magnetic properties in our study on polycrystalline films. The structures of epitaxially grown films were characterized by means of XRD. From P-E measurements, samples exhibited typical ferroelectric hysteresis loops and large remnant polarization, whose value is much larger than those of pure BFO film. The enhancement of dielectric, ferroelectric, magnetic properties was attributed to the structural distortion induced by the BCN addition and the high physical stress effect.