• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1586-1587
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• 2011

염료 감응 태양전지(DSCs)는 최근 큰 발전을 이루고 있지만, 효율개선과 비용절감 등의 과제를 여전히 안고 있다. 염료 감응 태양전지(DSCs)의 효율 상승을 위해 염료, $TiO_2$ 산화물, 투명전극, 전해질 및 Pt 전극에 관한 연구가 활발히 진행 되고 있다. 본 연구에서는 염료 감응 태양전지(DSCs)의 특성 분석을 위해 $TiO_2$ 두께를 $20{\mu}m$로 지정하고 면적을 $0.5{\times}0.5\;Cm^2$에서 $1.5{\times}1.5\;Cm^2$까지 증가시켜 개방전압($V_{oc}$), 단락전류밀도($J_{sc}$), 충진률 FF(%), 광전변환효율(${\eta}$)등의 특성을 분석해 보았다. 또한 염료가 흡착되는 시간을 12시간과 24시간으로 변화시켜 최적의 특성을 가지는 DSCs를 연구해 보았다.

• 조명전기설비학회논문지
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• 제23권1호
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• pp.176-181
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• 2009

본 연구에서는 염료 태양전지(Dye-sensitized solar cells; DSCs)에 적용하기 위한 나노-다공질의 FTO(F:$SnO_2$) 재료를 Sol-gel 연소법을 이용하여 다양한 열처리 온도를 변수로 제작하였으며, 각각의 결과물들에 대한 물성적 특성을 고찰하였다. FTO nano-powder는 SnCl4-98.0[%]와 HF-$48{\sim}51$[%]가 교반된 것에 NH4OH를 Sol-gel법의 촉매로 사용하였고, 첨가재로써 Ketjen Black을 사용하였다. 얻어진 결과물에 대한 XRD 측정 결과, 열처리 온도가 상승함에 따라 $SnO_2$의 회절각인 25.6[$^{\circ}$]($2{\Theta}$) 부근에서 강한 peak값이 나타났다. XPS 측정 결과에 의하면, 각각의 F1s, Sn 3d, O 1s의 binding energy는 682, 484, 528[eV]에서 광전자 피크가 확인되었다. 열처리 온도가 증가함에 따라 표면적이 감소하며, pore size는 증가함을 BET측정 결과로 알 수 있었다. 본 실험을 통해 열처리 온도조절에 따른 나노-다공성 FTO powder의 특성제어가 용이함이 확인되었고, Sol-gel 연소법에 의한 간단하고 효과적인 방법으로 나노-다공성 소재의 제작이 가능하여, DSCs의 응용에도 유용할 것으로 기대된다.

• 조명전기설비학회논문지
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• 제23권2호
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• pp.168-174
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• 2009

본 연구에서는 Poly(VdF-HFP)를 사용한 Gel Polymer 전해질을 제작하여 기존의 액상전해질과 비교하였다. 제작된 젤 고분자 전해질의 성분은 FTIR 분석을 사용하여 화학적 구조를 고찰한 후, 성분조사를 통해 Gel Polymer 전해질임을 확인하였으며, SEM 관측을 통해 Polymer 상태의 Gel 전해질의 구조를 확인하였다. 본 실험에서 제작된 젤 고분자 전해질을 구성하는 DEC와 PC의 최적의 성분비는 5 : 5임을 확인할 수 있었다. 최적조건의 젤 고분자전해질을 이용하여 제작된 염료 태양전지(DSCs)의 효율은 $3{\sim}4[%]$정도의 측정값을 얻었으며, 이상의 결과로부터 기존의 액상 전해질을 대체할 수 있는 준 고체형 염료태양전지의 제작이 가능함이 확인되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.52-56
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• 2006

Some of factors affecting photo-conversion efficiency of dye sensitized solar cells (DSCs) are discussed in terms of $TiO_2$ electrodes. The first topic is on the surface modification of $TiO_2$ nano-particles, which is associated with electron traps on the surface of $TiO_2$ nano-particles. The surface is modified with dye molecules under pressurized $CO_2$ atmosphere to increase the surface coverage of $TiO_2$ nano-particles with dye molecules. This increases Jsc because of an increase in the amount of dye molecules and a decrease in the amount of trapping sites on $TiO_2$ nano-particles. In addition, the decrease in the amount of trap sites increases Voc because decreases in Voc are brought about by the recombination of $I_2$ molecules with electrons trapped on the $TiO_2$ surfaces. Selective staining for tandem cells is proposed. The second topic is on the contact between a $SnO_2$/F transparent conductive layer (TCL) and nano-particles. Polishing the TCL surfaces with silica nano-particles increases the contact, resulting in Jsc increases. The third topic is the fabrication of ion-paths in $TiO_2$ layers. Electro-spray coating of $TiO_2$ nano-particles onto TCL is shown to be effective for fabricating ion-paths in $TiO_2$ layers, which increases Jsc.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.4035-4040
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• 2011

Long $TiO_2$ nanotube (NT) arrays, prepared by electrochemical anodization of Ti foils, have been utilized as dye-adsorbing electrodes in dye-sensitized solar cells (DSCs). By anodizing for 1-24 hr and subsequent annealing, highly crystallized and tightly-adhered NT arrays were tailored to 11-150 ${\mu}m$ lengths, ~90 nm innerpore diameter and ~30 nm wall thickness. I-V curves revealed that the photovoltaic conversion efficiency (${\eta}$) was proportional to the NT length up to 36 ${\mu}m$. Beyond this length, the ) was proportional to the NT length up to ${\eta}$ was still steadily increased, though at a much lower rate. For example, an ${\eta}$ of 5.05% at 36 ${\mu}m$ was increased to 6.18% at 150 ${\mu}m$. Transient photoelectron spectroscopic analyses indicated that NT array-based DSCs revealed considerably higher electron diffusion coefficient ($D_e$) and life time (${\tau}_e$) than those with $TiO_2$ nanoparticles (NP). Moreover, the electron diffusion lengths ($L_e$) of the photo-injected electrons were considerably larger than the corresponding NT lengths in all the cases, suggesting that electron transport in NT arrays is highly efficient, regardless of tube length.

• 전기학회논문지
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• 제58권1호
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• pp.100-106
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• 2009

A novel 8 V DC power source with an external series-parallel connection of 50 Dye-sensitized Solar Cells (DSCs) has been proposed. One DSC has the optimized length to width ratio of $5.2{\times}2.6\;cm$ and an active area $8\;cm^2$ ($4.62{\times}1.73\;cm$) which attained a conversion efficiency of 4.02%. From the electrochemical impedance spectroscopic analysis, it was found that the resistance elements related to the Pt electrode and electrolyte interface behave like that of diode and the series resistance corresponds to the sum of the other resistance elements. Surface morphology and sheet resistance of Pt counter electrode did not degrade the performance of the cell. This novel 8V-0.33A DC power source shows stable performance with an energy conversion efficiency of 4.24% under 1 sun illumination (AM 1.5, Pin of $100\;mW/cm^2$).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.75.2-75.2
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• 2013

Atomic layer deposition (ALD), utilizing self-limiting surface reactions, could offer promising perspectives for future efficient energy conversion devices. The capabilities of ALD for surface/interface modification and construction of novel architectures with sub-nanometer precision and exceptional conformality over high aspect ratio make it more valuable than any other deposition methods in nanoscale science and technology. In the context, a variety of researches on fabrication of active materials for energy conversion applications by ALD are emerging. Among those materials, one-dimensional nanotubular titanium dioxide, providing not only high specific surface area but also efficient carrier transport pathway, is a class of the most intensively explored materials for energy conversion systems, such as photovoltaic cells and photo/electrochemical devices. The monodisperse, stoichiometric, anatase, TiO2 nanotubes with smooth surface morphology and controlled wall thickness were fabricated via low-temperature template-directed ALD followed by subsequent annealing. The ALD-grown, anatase, TiO2 nanotubes in alumina template show unusual crystal growth behavior which allows to form remarkably large grains along axial direction over certain wall thickness. We also fabricated dye-sensitized solar cells (DSCs) introducing our anatase TiO2 nanotubes as photoanodes, and studied the effect of blocking layer, TiO2 thin films formed by ALD, on overall device efficiency. The photon convertsion efficiency ~7% were measured for our TiO2 nanotubebased DSCs with blocking layers, which is ~1% higher than ones without blocking layer. We also performed open circuit voltage decay measurement to estimate recombination rate in our cells, which is 3 times longer than conventional nanoparticulate photoanodes. The high efficiency of our ALD-grown, anatase, TiO2 nanotube-based DSCs may be attributed to both enhanced charge transport property of our TiO2 nanotubes photoanode and the suppression of recombination at the interface between transparent conducting electrode and iodine electrolytes by blocking layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.465-466
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• 2009

Dye-sensitized Solar Cell (DSC) is a new type of solar cell by using photocatalytic properties of $TiO_2$. The electric potential distribution in DSCs has played a major role in the operation of such cells. $TiO_2$ thin films were deposited on the ITO substrate by Nd:YAG Pulsed Laser Deposition(PLD) at room temperature and post-deposition annealing at $500^{\circ}C$ in flowing $O_2$ atmosphere for 1hour. The structural properties of $TiO_2$ thin films have investigated by X-ray diffraction(XRD). We manufactured DSC unit cells then I-V and efficiency were tested by solar simulator.

• Korean Chemical Engineering Research
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• 제54권2호
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• pp.262-267
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• 2016

본 연구에서는 건식플라즈마 환원방법을 이용하여 다중벽 탄소나노튜브(MWNT) 코팅 층 위에 백금, 금, 백금/금 이종 나노입자를 쉽고 균일하게 고정화 시킬 수 있는 방법을 제시한다. 나노입자는 다중벽 탄소나노튜브 위에 안정적이고 균일하게 고정화되어 나노하이브리드 소재가 되며, 이렇게 합성된 나노하이브리드 소재는 염료감응형 태양전지의 상대전극에 적용된다. CV, EIS, Tafel 측정을 통해 준비된 상대전극의 전기화학적 특성을 분석한 결과, PtAu alloy/MWNT 상대전극이 가장 높은 전기화학적 촉매 활성과 전기 전도도를 보여준다. PtAu alloy/MWNT 상대전극을 이용한 염료감응형 태양전지는 7.9%의 에너지 변환 효율을 보임으로써 MWNT (2.6%), AuNP/MWNT (2.7%) 그리고 PtNP/MWNT (7.5%) 상대전극을 사용한 염료감응형 태양전지의 효율과 비교하였을 때, 가장 높은 효율을 보여주고 있다.

• 전기학회논문지
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• 제62권2호
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• pp.208-212
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• 2013

Dye-sensitized solar cells (DSCs) have taken much attention due to their low cost and easy fabrication method compare to silicon solar cells. But research on cost effective DSC is prerequisite for commercialization. Fluorine doped tin oxide (FTO) which have been commonly used for electrode substrate as electron collector occupied most percentage of manufacturing cost. Therefore we studied FTO-less DSC using sputtered Ti deposited glass as photoelectrode instead of FTO to reduce manufacturing cost. Ti films sputtered on the glass for different time, 5 to 20 minutes with decreasing sheet resistance as deposition time increases. A light source illuminated to counter electrode in order to overcome opaque Ti films. The efficiency of DSC (Ti20) made Ti sputtered glass for 20 min as photoelectrode was 5.87%. There are no significant difference with conventional cell despite lower manufacturing cost.