• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.116-116
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• 2009

$TiO_2$ pastes was synthesized to obtained of high efficiency dye-sensitized solar cells using size dependent co-polymer. SBM co-polymer binder is consist of styrene, n-butyl acrylate, and methacrylic acid (SBM) monodisperse co-polymer binder materials and this $TiO_2$ pastes were applied of dye-sensitized solar cells (DSSCs). The photoanodes were characterized by ATR-Fourier Transform spectrometer, X-ray diffraction (XRD) and morphology was investigated by field emission scanning electron microscopy (FE-SEM). The photoelectrochemical properties of the thin films and the performance of DSSCs were measured by photovoltaic-current density, AC impedance and monochromatic incident photon-to-current conversion efficiency (IPCE). DSSC based on the 100nm size co-polymer binder was obtained conversion efficiency of 8.1% under irradiation of AM 1.5(100 $mWcm^2$).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.253-253
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• 2009

Electrospinning is one of the simple, cost- efficient methods to produce long continuous semiconducting oxide nanofibers. Polyvinyl Alcohol (PVA) and zinc acetate were used. PVA/Zinc acetate aqueous solutions were electrospun into nonwoven webs. CCD camera, with a lens of long working distance and digital video board were used in capturing the drop and web deposition. The diameter and morphology of nanofibers were analyzed with a Field-emission scanning electron microscopy (FE-SEM). In this study, the average diameter and morphology of nanofibers have been explorered.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.316.2-316.2
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• 2016

Device가 점점 Shrinkage 됨에 따라 미세 패터닝을 위하여 기존에 사용하던 박막은 Hardmask 로써 CD(Critical Dimension)가 제한적으로 이를 개선하기 위한 비정질 실리콘 (amorphous silicon)으로 대체하여 사용되는 Layer의 수가 증가하고 있다. 하지만 비정질 실리콘을 증착 시, 하부막에 따른 Adhesion 및 Hillocks과 같은 공정상에서 발생하는 문제들이 발생하게 되는데, 이는 소자의 특성을 떨어뜨리게 된다. 이러한 문제를 해결하고자 본 연구에서는 PECVD를 사용하여 비정질 실리콘 박막을 증착하였고, 그 특성을 분석하였으며, Adhesion 및 Hillock 개선을 위해 비정질 실리콘 박막 증착 전 처리를 최적화하여 특성을 개선하였다. 증착된 박막의 두께 및 굴절률은 Auto thickness measurement로 분석하였고, 표면 특성은 Field emission scanning electron microscopy(FE-SEM 그림 참고), 4 Point Bending TEST를 이용하여 분석을 수행하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.245-245
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• 2016

본 연구에서는 선형 대향 타겟 스퍼터 (Linear Facing Target Sputtering: LFTS) 시스템을 이용하여 ITO와 Ti doped $In_2O_3$ (TIO) 타겟을 Co-sputtering한 InSnTiO 투명 전극의 전기적, 광학적 특성을 연구하였다. InSnTiO 투명전극의 전기/광학적 및 구조적 특성은 Hall measurement, UV/Vis spectrometry, X-ray Diffraciton 분석법을 통해 최적화 하였고, DC power, substrate to target distance (TSD), target to target distance (TTD), ambient treatment 변수 조절을 통해 최적화된 LFTS InSnTiO 투명전극을 제작하였다. LFTS 공정을 이용한 InSnTiO 투명전극의 성막 공정 중 DC파워와 공정압력 변화에 따른 구조적, 표면적 특성 변화는 Field-Emission Scanning Electron Microscopy (FE-SEM) 과 X-ray Diffractometer (XRD) 분석을 통해 관찰하였다. 이렇게 증착된 InSnTiO 투명전극은 급속열처리 시스템으로 (Rapid Thermal Annealing system) 후열처리를 진행하여 투과도의 향상과 면저항의 감소를 확인하였다. 본 연구에서는 다양한 분석을 통해 Co-sputtering한 InSnTiO 박막의 특성과 다양한 장점을 소개한다.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.903-909
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• 2015

In this study, we used GO (graphene oxide) in order to enhance the adhesion between Ag NWs (nanowires) and substrates. By using a mixture solution of GO and Ag NW, a vacuum filtration process was used to fabricate a 50nm diameter thin film. Next, by using a light annealing process, the mechanical and electrical stability of Ag NW network was improved without any other treatment. The physical properties of the Ag NW - GO hybrid transparent conductive thin film was characterized in terms of a bending test, resistance and transmittance test, and nanoscale imaging using field-emission scanning electron microscopy.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.1047-1048
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• 2004

Simulation Coated layers of a nuclear fuel particle were evaluated by field emission scanning electron microscopy and nano-indentation method to give basic data to estimate 'Amoeba effect' and give an optimum fabrication condition and high quality control. Coated layers on the fuel kernel are in the order of buffer pyrolytic carbon, inner pyrolytic carbon, silicon carbide and outer pyrolytic carbon layers, which average thicknesses are 95, 25, 30 and 28 ${\mu}m$, respectively. Their densities and hardnesses are 1.08, 1.15, 3.18, 1.82 $g/cm^3$ and 0.522, 0.874, 9.641, and 2.726 GPa, respectively. Comparing theoretical density of pyrolytic carbon of 2.22 $g/cm^3$, the relative amount of porosity in each layer is about 52% for buffer, 48% for inner PyC and 18% for outer PyC.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.157.2-157.2
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• 2011

In this work, we prepared Mg nanoparticles loaded graphite oxide (Mg-G) as a function of Mg content in order to investigate hydrogen storage behaviors. The structure and morphology of the Mg-G samples were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The textural properties of the samples were evaluated using $N_2$/77 K adsorption isotherms. The hydrogen adsorption capacities were investigated at 298 K/10 MPa. As a result, the hydrogen adsorption capacities of the Mg-G were enhanced with increasing the Mg content. Therefore, it was found that the presence of Mg on graphite surfaces created hydrogen-favorable sites, resulting in enhancing the hydrogen adsorption capacity.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.160-160
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• 2013

Dye-sensitized solar cells (DSSCs) have attracted much attention because of their moderate light-to-electricity conversion efficiency, easy fabrication, and low cost. At present, platinum (Pt) is used as a counter electrode in DSSCs. However, it is found that Pt dissolves in iodide electrolyte solutions and creates chemical compound such as PtI4 and H2PtI6. Carbon based materials are one of candidates for a counter electrode of DSSCs. We prepare two types of graphite oxides by different chemical treatments; original graphite oxide, hydrazine treated graphite oxide. Each graphite oxide and magnesium nitrate dispersed in deionized water are prepared as solutions for electrophoretic deposition (EPD). Each graphite oxide electrode is deposited on fluorine-doped tin oxide (FTO) substrate by EPD method. Structural and electrochemical properties of each electrode are investigated by field-emission scanning electron microscopy and electrochemical impedance spectroscopy, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.309-309
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• 2013

기존의 CIGS 태양전지는 window 층(GZO/ZnO/CdS)에서의 투과 및 반사 손실을 줄이기 위하여 MgF2를 이용한 AR (Anti Reflection) 층을 적용하여 cell을 제작하고 있다. 현재 단위공정을 줄이고 시간적 경제적 비용을 절감하기위해 무반사 코팅층 없이 표면의 구조를 변화 시키거나 CIGS 태양전지의 window 층만으로 cell 구조에 적용하는 연구가 많이 진행되고 있다. 본 연구는 AR층과 window층 역할을 동시에 만족하는 일체화된 window층 두께를 설계하고 성장한 후, window층의 열처리 전후의 구조적, 광학적 및 전기적 특성을 비교 평가하였다. Macleod simulation을 이용하여 window 층을 설계한 후, RF magnetron sputtering법을 이용하여 상온성장 시킨 후 N2 분위기에서 후열처리 조건에 따른 박막의 구조적, 전기적 및 광학적 특성을 변화를 X-ray diffractometer, Field emission-scanning electron microscope, Atomic force microscopy, 4 point probe, Hall 측정, 투과도 및 반사도등으로 비교 평가하였다.

• Current Photovoltaic Research
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• v.4 no.2
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• pp.42-47
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• 2016

Increasing the efficiency of dye-sensitized solar cells (DSSCs) by the fabrication of new photoelectrodes (PEs) is an important challenge. This study examined the photovoltaic parameters of DSSCs composed of a $TiO_2$ PE with $WO_3$ nanoparticles (NPs). A number of PEs with the same thickness but different concentrations of $WO_3$ NPs in the $TiO_2PE$ were prepared. The morphology and structural properties of the prepared PEs were examined by field-emission scanning electron microscopy and X-ray diffraction, respectively. The effects of the $WO_3$ NPs mixing concentration on the efficiency of DSSCs were investigated under simulated solar light irradiation.