• Korean Chemical Engineering Research
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• 제56권4호
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• pp.447-452
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• 2018

HF, NaF, $NH_4F$와 같이 플루오르 이온(F-)이 함유된 전해질에서 티타늄 금속판을 양극산화시켜 $0.34{\mu}m$부터 최대 $8.9{\mu}m$까지 다양한 길이의 티타니아 나노튜브(TNT)를 제조하였다. 양극산화에 의해 제조된 TNT를 $450^{\circ}C$에서 소성시키면 광 활성을 가지는 아나타제 결정이 생성되었다. TNT 기반 염료감응 태양전지(DSSC)는 TNT 길이가 $2.5{\mu}m$일때 광전환 효율이 4.71%로 최대를 나타내었다. 이 값은 티타니아 페이스트를 코팅하여 제작한 FTO 기반 DSSC의 광전환 효율 보다 약 18% 높았다. 또한 TNT-DSSC의 단락전류밀도($J_{sc}$)는 $9.74mA/cm^2$로 FTO-DSSC의 $7.19mA/cm^2$ 보다 약 35% 이상 높았다. TNT-DSSC 태양전지의 광전환 효율이 더 높은 이유는 염료에서 생성된 광전자가 TNT를 통해 전극 표면으로 빨리 전달되어 광전자와 염료가 재결합 되는 것이 억제되었기 때문이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.294-294
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• 2010

Over the last decade, dye-sensitized solar cell (DSSC) has attracted much attention due to the high solar-to-electricity conversion efficiency up to 10% as well as low cost compared with p-n junction photovoltaic devices. DSSC is composed of mesoporous TiO2 nanoparticle electrodes coated with photo-sensitized dye, the redox electrolyte and the metal counter electrode. The performances of DSSC are dependent on constituent materials and interface as well as device structure. Replacing the heavy glass substrate with plastic materials is crucial to enlarge DSSC applications for the competition with inorganic based thin film photovoltaic devices. One of the biggest problems with plastic substrates is their low-temperature tolerance, which makes sintering of the photoelectrode films impossible. Therefore, the most important step toward the low-temperature DSSC fabrication is how to enhance interparticle connection at the temperature lower than $150^{\circ}C$. In this talk, the key issues for high efficiency plastic solar cells will be discussed, and several strategies for the improvement of interconnection of nanoparticles and bendability will also be proposed.

• 반도체디스플레이기술학회지
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• 제10권2호
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• pp.65-71
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• 2011

Properties of each layer in DSSC were investigated to improve solar cell characterstics. Also in this study, low costsolar simulator system is fabricated and used. Efficiency of DSSC is better in the case of thinner semiconductive layer, because thick semiconductive layer is acted as resistor. Sc-doped ZnO thin films showed better electrical property by proper donor doping effect. Among the dyes, DSSC containing N719 showed higher efficiency, because N719 have smaller electron affinity and shallow band gap.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.337-337
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• 2012

Dye sensitized solar cell (DSSC) having high efficiency with low cost was first reported by Gr$\ddot{a}$tzel et al. Many DSSC research groups attempt to enhance energy conversion efficiency by modifying the dye, electrolyte, Pt-coated electrode, and $TiO_2$ films. However, there are still some problems against realization of high-sensitivity DSSC such as the recombination of injected electrons in conduction band and the limited adsorption of dye on $TiO_2$ surface. The surface of $TiO_2$ is very important for improving hydrophilic property and dye adsorption on its surface. In this paper, we report a very efficient method to improve the efficiency and stability of DSSC with nano-structured $TiO_2$. Atmospheric plasma system was utilized for nitrogen plasma treatment on nano-structured $TiO_2$ film. We confirmed that the efficiency of DSSC was significantly dependent on plasma power. Relative in the $TiO_2$ surface change and characteristics after plasma was investigated by various analysis methods. The structure of $TiO_2$ films was examined by X-ray diffraction (XRD). The morphology of $TiO_2$ films was observed using a field emission scanning electron microscope (FE-SEM). The surface elemental composition was determined using X-ray photoelectron spectroscopy (XPS). Each of plasma power differently affected conversion efficiency of DSSC with plasma-treated $TiO_2$ compared to untreated DSSC under AM 1.5 G spectral illumination of $100mWcm^{-2}$.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1853-1856
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• 2013

$TiO_2$ hollow nanoparticles (HNPs) and their light scattering effect which influences on the photoelectric conversion efficiency of a dye-sensitized solar cell (DSSC) were investigated. When only HNPs were employed in DSSC as the anode layer material, the conversion efficiency (e.g., 0.96%) was the lowest, possibly due to scattering loss of incident light. However, DSSC fabricated by using HNPs as a scattering overlayer on the $TiO_2$ nanoparticles (P-25), showed higher conversion efficiency (4.02%) than that without using HNPs (3.36%).

• 한국전기전자재료학회논문지
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• 제25권4호
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• pp.315-320
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• 2012

In general, a photoelectrode in DSSC(dye sensitized solar cell) are fabricated by using the $TiO_2$ (Titanium dioxide) to realize high efficiency and the efficiency of DSSC is affected by the size, the shape and the property of $TiO_2$. We synthesized the crystalline $TiO_2$ by sol-gel method. In spite of many merits, only weakness for the sol-gel method is taking many process times. To solve this problem, we reduced the fabricating processes. The reduced process is the making process that is $TiO_2$ sol to $TiO_2$ powder with including of two heat treatment and two mixing. We could simplify the process by preparing $TiO_2$ sol to $TiO_2$ paste directly. As a result, DSSC fabrication process is simplified and we have obtained the efficiency best result 3.88% with $V_{OC}$=0.71 V, $J_{SC}=8.70\;mA/cm^{-2}$, and FF=62.37%, respectively.

• 반도체디스플레이기술학회지
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• 제11권1호
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• pp.41-47
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• 2012

In DSSC, fundamental process conditions of upper electrode were established and low cost-oriented method for TCO layer was proposed. Especially, prominent properties, that is, open-circuit voltage of 500mV or more and short-circuit current of $25mA/cm^2$ were yielded by 2-step sintering of semiconductive powder layer. High efficiency-DSSC was able to fabricate without high cost-semiconductor apparatus in common laboratory conditions.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.57.2-57.2
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• 2011

Dye-sensitized solar cells (DSSC) have recently been developed as a cost-effective photovoltaic system due to their low-cost materials and facile processing. The production of DSSC involves chemical and thermal processes but no vacuum is involved. Therefore, DSSC can be fabricated without using expensive equipment. The use of dyes and nanocrystalline $TiO_2$ is one of the most promising approaches to realize both high performance and low cost. The efficiency of the DSSC changes consequently in the particle size, morphology, crystallization and surface state of the $TiO_2$. Nanocrystalline $TiO_2$ materials have been widely used as a photo catalyst and an electron collector in DSSC. Front electrode in DSSC are required to have an extremely high porosity and surface area such that the dyes can be sufficiently adsorbed and be electronically interconnected, resulting in the efficient generation of photocurrent within cells. In this study, DSSC were fabricated by an screen printing for the $TiO_2$ thin film. $TiO_2$ nanoparticles characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM) and scanning auger microscopy (SAM) and zeta potential and electrochemical impedance spectroscopy(EIS).In addition, DSSC module was modeled and simulated using the SILVACO TCAD software program. Improve the efficiency of DSSC, the effect of $TiO_2$ thin film thickness and $TiO_2$ nanoparticle size was investigated by SILVACO TCAD software program.

• 한국수소및신에너지학회논문집
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• 제24권5호
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• pp.421-427
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• 2013

We report on the time dependent degradation of cell in dye-sensitized solar cells (DSSC). The photovoltaic performance of DSSC over a period of time was investigated in liquid electrolyte based on triiodide/iodide during six days. It was found that the short circuit current density ($j_{sc}$) of the cell dropped from 9.9 to $7mA/cm^2$ while efficiency (${\eta}$) of the cell decreased from 4.4 to 3.3%. The parameters corresponding to fundamental electronic and ionic processes in a working DSSC are determined from the electrochemical impedance spectrascopy (EIS) at open-circuit potential ($V_{oc}$). EIS study of the DSSC in the this work showed that the electron life time ${\tau}_r$ and chemical capacitance $C_{\mu}$ decreased significantly after six days. It was correlated the $j_{sc}$ and efficiency decreased after six days.

• 한국전기전자재료학회논문지
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• 제32권1호
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• pp.53-57
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• 2019

Recently, the application field of solar panels is increasing. Accordingly, the demand for flexible devices is also steadily increasing. It is therefore necessary to develop $TiO_2$ paste for low-temperature annealing for flexible DSSC fabrication. In this study, the $TiO_2$ paste for low-temperature annealing with varying molar ratio of titanium isopropoxide (TTIP) was prepared, and DSSC was fabricated and its characteristics were compared. As a result, there was no deformation of the particles on the surface in the SEM data. However, the highest open circuit voltage, short circuit current, and fill factor were measured in the DSSC unit cell prepared by adding 0.5 mol of TTIP to the $TiO_2$ paste, and the highest efficiency was 4.148%.