• 산업융합연구
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• 제20권10호
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• pp.33-38
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• 2022

본 논문에서는 용액 기반의 탄소나노튜브(CNT: Carbon Nano-tube)를 전자기기의 전도성 소재로 사용하기 위하여 쉽고 빠르게 형성하는 방법에 대해 연구하였다. 이를 위해 스핀 코팅 방법 및 아르곤 상압플라즈마 공정을 적용하여 글라스 위에 CNT 박막 코팅을 진행하였다. 코팅 횟수에 따른 전기적, 물리적 특성 변화를 관찰하기 위하여 1회부터 5회까지 동일한 방법으로 형성된 샘플을 제작하였고, 각 샘플에 대해 표면 형상, 반사도, 투과도, 흡수율 및 표면 저항을 측정하였다. 현미경을 이용하여 관찰했을 때 횟수가 늘어날 때 글라스 상에 검은 형상이 더 잘 관찰되며, 특히 스핀코팅에 의해 가운데 영역이 더 검게 관찰되는 것을 알 수 있다. 코팅 수가 증가함에 따라 측정 파장의 전 영역에서 투과도는 감소, 반사도 및 흡수율은 증가하였다. 또한, 파장이 감소함에 따라 투과율은 감소, 반사도 및 흡수율은 증가한다. 전기적인 특성의 경우, 2번 코팅했을 때 전도도가 상당히 향상됨을 확인할 수 있었으며, 추가 코팅에 의해서 전도도 감소가 관찰되지만, 큰 변화를 보이지는 않았다. 결론적으로 CNT를 투명전극으로 대체하기 위해서는 반사도 및 전기전도도를 함께 고려하여 코팅 횟수를 고려해야 하며, 2회가 최적임을 알 수 있다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.541-548
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• 2012

New candidates composed of anthracene and 4-alkylethynylbenzene end-capped oligomers for OTFTs were synthesized under Sonogashira coupling reaction conditions. All oligomers were characterized by FT-IR, mass, UV-visible, and PL emission spectrum analyses, cyclic voltammetry (CV), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), $^1H$-NMR, and $^{13}C$-NMR. Investigation of their physical properties showed that the oligomers had high oxidation potential and thermal stability. Thin films of DHPEAnt and DDPEAnt were characterized by spin coating them onto Si/$SiO_2$ to fabricate top-contact OTFTs. The devices prepared using DHPEAnt and DDPEAnt showed hole field-effect mobilities of $4.0{\times}10^{-3}cm^2$/Vs and $2.0{\times}10^{-3}cm^2$/Vs, respectively, for solution-processed OTFTs.

• 한국세라믹학회지
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• 제45권9호
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• pp.524-530
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• 2008

Anti-Reflective (AR) thin film coatings of $SiO_2$ (n= 1.48) and $TiO_2$ (n=2.17) were deposited by ion-beam assisted deposition (IBAD) with End-Hall ion source and conventional electron beam (e-beam) evaporation to investigate the effect of deposition method on the refractive indicies (n) of the fIlms. Green-light generation using a GaAs laser diode was achieved via excitation of the second harmonic. The latter resulted from the transmission of the fundamental guided-mode wave of 1064 nm through periodically poled $LiNbO_3$. Large differences in the refractive indicies of each of the layers in the multilayer coating may improve AR performance. IBAD of $SiO_2$ reduced its refractive index from 1.45 to 1.34 at 1064 nm. Conversely, e-beam evaporation of $TiO_2$ increased its refractive index from 1.80 to 2.11. In addition, no fluctuations in absorption at the wavelength of 1064 nm were found. The results suggest that films prepared by different deposition methods can increase the effectiveness of multilayer AR coatings.

• 한국세라믹학회지
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• 제43권2호
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• pp.114-120
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• 2006

Nano-size Au particle doped $TiO_2$ films were prepared with $Ti(OC_3H_7^i)_4$, polyvinylpyrrolidone(PVP), $HAuCl_4$ and $C_3H_7OH$ etc. by sol-gel method. $TiO_2$ gel films were obtained by the dip-coating method on the $SiO_2$ glass substrates, and then heat-treated at $700^{\circ}C$ for 10 min. The thickness of $TiO_2$ films were $0.7\~1.8\;{\mu}m$. It was found that the thickness of films prepared from PVP containing solution was about $2\~8$ times higher values than that of thin films without PVP. The size of Au particles doped in the films were about $350\~750\;nm$. Nano-size Au particle dispersed $TiO_2$ films showed high absorption peak at visible region 450nm, which made them good candidates for non-linear optical materials and photo-catalytic materials. The contact angle of $TiO_2$ film for water was $12.5^{\circ}$, and therefore it is clear that $TiO_2$ films have very high hydrophilic properties and the self-cleaning effects.

• 한국가스학회지
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• 제9권4호
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• pp.26-29
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• 2005

본 연구에서는 Metallophthalocyanine Macrocyclic Compounds인 Zinc phthalocyanine(ZnPc)를 이용하여 박막 films를 만들어 solvent sensor의 특성에 대한 연구을 수행하였다. 측정에 사용한 유기용제의 종류는 Acetic acid, Ethyl alcohol, Methyl alcohol, Ammonia 및 1,1,1-trichloroethane이였으며, solvent sensing 특성으로는 전기저항 변화를 측정 분석하였다. 또한 Zinc phthalocyanines과 $N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,\;1-biphenyl-4,4'-diamine\;and/or\; Poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene-vinylene]$를 blend하여 spin-coating, evaporation박막을 만들어 유기용제 농도에 따라서 전기 저항 변화를 측정 분석하였다.

• 한국진공학회지
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• 제21권1호
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• pp.22-28
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• 2012

건물일체형 태양전지는 투명 연료감응형 태양전지 기술을 중심으로 연구개발이 진행되고 있다. 신뢰성-수율 개선 및 대면적화의 필요성 때문에 잘 정립된 박막 공정 기술에 기초하는 Si계 박막 태양전지가 건물일체형 태양전지를 구현할 기술로서 새롭게 조명 받고 있다. Si계 박막 태양전지에 선택적 투과막을 적용하면 가시광선은 태양전지를 투과하고 적외선은 광흡수층으로 반사되기 때문에 투명 태양전지의 변환효율이 향상된다. 본 연구에서는 선택적 투과막의 증착 기술로서 생산성 측면에서 유리한 스퍼터 증착을 이용하여 AlTiO 선택적 투과막을 형성하고 증착 조건을 조절하여 투과율을 향상시켰다.

• 마이크로전자및패키징학회지
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• 제15권4호
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• pp.101-106
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• 2008

이산화질소를 감지할 수 있는 센서물질로 Pd과 탄소 나노튜브(CNT)가 첨가된 $SnO_2$ 박막을 스핀코팅으로 제조하였으며, 동 시편의 이산화질소에 대한 감지 특성을 $200^{\circ}C$ 및 $1ppm{\sim}5ppm$의 $NO_2$ 농도 하에서 측정하였다. 센서시편의 전기저항은 $NO_2$ 기체의 노출과 농도에 따라 증가 하였으며, Pd이 3wt%로 첨가된 시편의 감도는 26.5로 첨가전의 감도에 비하여 10배 증가하였다. 또한 $SnO_2$ 모체에 첨가한 CNT의 량에 따라서도 감도는 증가 하였으며, 0.225wt% CNT 첨가 시 5ppm의 $NO_2$ 농도에서 감도 값은 72이었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.469-472
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• 1999

CeO$_2$ thin films have used in wide applications such as SOI, buffer layer, antirflection coating, and gate dielectric layer. CeO$_2$takes one of the cubic system of fluorite structure and shows similar lattice constant (a=0.541nm) to silicon (a=0.543nm). We investigated CeO$_2$films as buffer layer material for nonvolatile memory device application of a single transistor. Aiming at the single transistor FRAM device with a gate region configuration of PZT/CeO$_2$ /P-Si , this paper focused on CeO$_2$-Si interface properties. CeO$_2$ films were grown on P-type Si(100) substrates by 13.56MHz RF magnetron sputtering system using a 2 inch Ce metal target. To characterize the CeO$_2$ films, we employed an XRD, AFM, C-V, and I-V for structural, surface morphological, and electrical property investigations, respectively. This paper demonstrates the best lattice mismatch as low as 0.2 % and average surface roughness down to 6.8 $\AA$. MIS structure of CeO$_2$ shows that breakdown electric field of 1.2 MV/cm, dielectric constant around 13.6 at growth temperature of 200 $^{\circ}C$, and interface state densities as low as 1.84$\times$10$^{11}$ cm $^{-1}$ eV$^{-1}$ . We probes the material properties of CeO$_2$ films for a buffer layer of FRAM applications.

• Current Photovoltaic Research
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• 제8권4호
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• pp.114-119
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• 2020

In this study, Mitigation of Potential-induced degradation (PID) for PERC solar cells using SiO2 Structure of ARC layer. The conventional PID test was conducted with a cell-level test based on the IEC-62804 test standard, but a copper PID test device was manufactured to increase the PID detection rate. The accelerated aging test was conducted by maintaining 96 hours with a potential difference of 1000 V at a temperature of 60℃. As a result, the PERC solar cell of SiO2-Free ARC structure decreased 22.11% compared to the initial efficiency, and the PERC solar cell of the Upper-SiO2 ARC structure decreased 30.78% of the initial efficiency and the PID reliability was not good. However, the PERC solar cell with the lower-SiO2 ARC structure reduced only 2.44%, effectively mitigating the degradation of PID. Na+ ions in the cover glass generate PID on the surface of the PERC solar cell. In order to prevent PID, the structure of SiNx and SiO2 thin films of the ARC layer is important. SiO2 thin film must be deposited on bottom of ARC layer and the surface of the PERC solar cell N-type emitter to prevent surface recombination and stacking fault defects of the PERC solar cell and mitigated PID degradation.

• 센서학회지
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• 제31권5호
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• pp.337-342
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• 2022

Hydrogen (H₂) gas is widely preferred for use as a renewable energy source owing to its characteristics such as environmental friendliness and a high energy density. However, H₂ can easily reverse or explode due to minor external factors. Therefore, H₂ gas monitoring is crucial, especially when the H₂ concentration is close to the lower explosive limit. In this study, metal oxide materials and their p-n heterojunctions were synthesized by a hydrothermal-assisted dip-coating method. The synthesized thin films were used as sensing materials for H₂ gas. When the H₂ concentration was varied, all metal oxide materials exhibited different gas sensitivities. The performance of the metal oxide gas sensor was analyzed to identify parameters that could improve the performance, such as the choice of the metal oxide material, effect of the p-n heterojunctions, and operating temperature conditions of the gas sensor. The experimental results demonstrated that a CuO/ZnO gas sensor with a p-n heterojunction exhibited a high sensitivity and fast response time (134.9% and 8 s, respectively) to 5% H₂ gas at an operating temperature of 300℃.