• Korean Chemical Engineering Research
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• 제48권4호
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• pp.506-510
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• 2010

염료감응 태양전지에서 $TiO_2$의 표면에서 일어나는 전자의 재결합 현상은 태양전지의 변환효율을 떨어뜨리는 주요한 원인이다. 본 연구에서는 이 전자의 재결합 현상을 제어하기 위해 $TiO_2$의 표면에 에너지 장벽을 도입하여 변환효율을 향상시키고자 하였다. $TiO_2$ 나노전극에 에너지 장벽의 역할을 하는 $Nb_2O_5$를 코팅시켰다. 코팅의 영향을 알아보기 위해 코팅횟수를 변화시키며 실험하였다. 가시광선 영역에서의 반사율로부터 코팅의 유무를 확인하고 회절패턴으로부터 코팅물질이 $Nb_2O_5$임을 확인하였다. 재결합을 제어할 수 있는 코팅막의 두께를 측정해 본 결과, 12회 코팅하였을 때 코팅막의 두께는 약 5 nm로 1회 코팅시 적층되는 코팅막의 두께는 약 0.417 nm로 볼 수 있었다. 코팅횟수에 따른 변환효율의 변화는 코팅막이 없는 경우 2.55%에서 2회 코팅한 경우 4.25%로 약 1.7배 증가하여 2회 코팅의 경우 효율이 가장 높았다. 따라서 $Nb_2O_5$ 2회 코팅의 경우 코팅막의 두께가 약 0.834 nm로 전자의 재결합을 가장 잘 제어할 수 있었다.

• 한국디지털건축인테리어학회논문집
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• 제12권3호
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• pp.5-13
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• 2012

In this study, features and design effects of PV(Photovoltaic) modules were classified to help the installation of BIPV(Building Integrated Photovoltaic) In addition, through domestic and international trends and cases survey, installation method was organized and applicable range of efficiency and design from First-generation solar cells to the third-generation solar cell was classified. Frist, Crystalline Solar cell module of first-generation is appropriate for the wall type, roof, louver, shading and etc. It has superiority of technology and price stability and can be achieved by a variety of aesthetic effects. Second, Dye-Sensitized Solar Cell of Thin Film solar cell can express a variety of colors, adjust light transmittance and maximize the aesthetic splendor. It is appropriate for the wall type, window type, curtain wall type and etc. Also, see-through type solar cell can provide comforts cause of free flow of light. And it is advantageous from economic due to adjust the indoor temperature. It is appropriate for the atrium type, curtain wall type, window type and etc.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.71-71
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• 2011

Dye-sensitized solar cells (DSCs) have drawn great academic attention due to their potential as low-cost renewable energy sources. DSCs contain a nanostructured TiO2 photoanode, which is a key-component for high conversion efficiency. Particularly, one-dimensional (1-D) nanostructured photoanodes can enhance the electron transport for the efficient collection to the conducting substrate in competition with the recombination processes. This is because photoelectron colletion is determined by trapping/detrapping events along the site of the electron traps (defects, surface states, grain boundaries, and self-trapping). Therefore, 1-D nanostructured photoanodes are advantageous for the fast electron transport due to their desirable features of greatly reduced intercrystalline contacts with specified directionality. In particular, anodic TiO2 nanotube (NT) electrodes recently have been intensively explored owing to their ideal structure for application in DSCs. Besides the enhanced electron transport properties resulted from the 1-D structure, highly ordered and vertically oriented nanostructure of anodic TiO2 NT can contribute additional merits, such as enhanced electrolyte diffusion, better interfacial contact with viscous electrolytes. First, to confirm the advantages of 1-D nanostructured material for the photoelectron collection, we compared the electron transport and charge recombination characteristics between nanoparticle (NP)- and nanorod (NR)-based photoanodes in DSCs by the stepped light-induced transient measurements of photocurrent and voltage (SLIM-PCV). We confirmed that the electron lifetime of the NR-based photoanode was much longer than that of the NP-based photoanode. In addition, highly ordered and vertically oriented TiO2 NT photoanodes were prepared by electrochemical anodization method. We compared the photovoltaic properties of DSCs utilizing TiO2 NT photoanodes prepared by one-step anodization and two-step anodization. And, to reduce the charge recombination rate, energy barrier layer (ZnO, Al2O3)-coated TiO2 NTs also applied in DSC. Furthermore, we applied the TiO2 NT photoanode in DSCs using a viscous electrolyte, i.e., cobalt bipyridyl redox electrolyte, and confirmed that the pore structure of NT array can enhance the performances of this viscous electrolyte.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1081-1088
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• 2013

Two new metal-free organic dyes bridged by anthracene-mediated ${\pi}$-conjugated moieties were successfully synthesized for use in a dye-sensitized solar cell (DSSC). A N,N-diphenylthiophen-2-amine unit in these dyes acts as an electron donor, while a (E)-2-cyano-3-(thiophen-2-yl)acrylic acid group acts as an electron acceptor and an anchoring group to the $TiO_2$ electrode. The photovoltaic properties of (E)-2-cyano-3-(5-((10-(5-(diphenylamino)thiophen-2-yl)anthracen-9-yl)ethynyl)thiophen-2-yl)acrylic acid (DPATAT) and (E)-2-cyano-3-(5'-((10-(5-(diphenylamino)thiophen-2-yl)anthracen-9-yl)ethynyl)-2,2'-bithiophen-5-yl)acrylic acid (DPATABT) were investigated to identify the effect of conjugation length between electron donor and acceptor on the DSSC performance. By introducing an anthracene moiety into the dye structure, together with a triple bond and thiophene moieties for fine-tuning of molecular configurations and for broadening the absorption spectra, the short-circuit photocurrent densities ($J_{sc}$), and open-circuit photovoltages ($V_{oc}$) of DSSCs were improved. The improvement of $J_{sc}$ in DSSC made of DPATABT might be attributed to much broader absorption spectrum and higher molecular extinction coefficient (${\varepsilon}$) in the visible wavelength range. The DPATABT-based DSSC showed the highest power conversion efficiency (PCE) of 3.34% (${\eta}_{max}$ = 3.70%) under AM 1.5 illumination ($100mWcm^{-2}$) in a photoactive area of $0.41cm^2$, with the $J_{sc}$ of $7.89mAcm^{-2}$, the $V_{oc}$ of 0.59 V, and the fill factor (FF) of 72%. In brief, the solar cell performance with DPATABT was found to be better than that of DPATAT-based DSSC.

• 한국분말재료학회지
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• 제25권4호
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• pp.309-315
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• 2018

In the present work, we synthesize nano-sized ZnO, $SnO_2$, and $TiO_2$ powders by hydrothermal reaction using metal chlorides. We also examine the energy-storage characteristics of the resulting materials to evaluate the potential application of these powders to dye-sensitized solar cells. The control of processing parameters such as pressure, temperature, and the concentration of aqueous solution results in the formation of a variety of powder morphologies with different sizes. Nano-rod, nano-flower, and spherical powders are easily formed with the present method. Heat treatment after the hydrothermal reaction usually increases the size of the powder. At temperatures above $1000^{\circ}C$, a complete collapse of the shape occurs. With regard to the capacity of DSSC materials, the hydrothermally synthesized $TiO_2$ results in the highest current density of $9.1mA/cm^2$ among the examined oxides. This is attributed to the fine particle size and morphology with large specific surface area.

• 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.

• 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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1295-1296
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• 2007

A lot of researches about dye-sensitized solar cell (DSC) are recently being conducted. Because DSC has several advantages to pass the limits of silicon solar cells such as a low manufacturing expense, a simple manufacturing process and its transparency. But most researches on DSC are still conducted about the unit cell and laboratory-centered. That is, present researches on DSC are not practical. Therefore, researches about large area cells and modules have to be prerequisites for DSC to have the practicality. Characteristics of large area DSC are so different from those of small area DSC in aspect of fill factor and efficiency. In this study, we made an experiment on finding suitable size of DSC that has the most effective power according to the variation of active area. In detail, the experiment was conducted about the optimum ratio of length to width and we introduced the ratio of active area to non-active area to find the active area which has the best output. Because small DSC doesn‘t have the best output in comparison with total area of cell although the smaller DSC has the better efficiency. As a result, we achieved the optimum ratio of length to width of 8:3 and active area of $8cm^2$ as the optimum size for upscaling DSC.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2329-2337
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• 2009

Three heteroleptic ruthenium sensitizers, Ru(L)($L^1)(NCS)_2$ [L = 4,4'-dicarboxylic acid-2,2'-bipyridine, Ru-T1: $L^1$ = (E)-2-(4'-methyl-2,2'-bipyridin-4-yl)-3-(thiophen-2-yl)acrylonitrile, Ru-T2: $L^2$ = (E)-3-(5'-hexyl-2,2'-bithiophen-5- yl)-2-(4'-methyl-2,2'-bipyridin-4-yl)acrylonitrile, and Ru-T3: $L^3$ = (E)-3-(5"-hexyl-2,2':5',2"-terthiophen-5-yl)-2- (4'-methyl-2,2'-bipyridin-4-yl)acrylonitrile)], were synthesized and used as photosensitizers in nanocrystalline dyesensitized solar cells (DSSCs). The introduction of the 3-(5-hexyloligothiophen-5-yl)acrylonitrile group increased the conjugation length of the bipyridine donor ligand and thus improved their molar absorption coefficient and light harvesting efficiency. DSSCs with the configuration of Sn$O_2$: F/Ti$O_2$/ruthenium dye/liquid electrolyte/Pt devices were fabricated using these Ru-$T1{\sim}T3$ as a photosensitizers. Among the devices, the DSSCs composed of Ru-T2 exhibited highest power conversion efficiency (PCE) of 2.84% under AM 1.5 G illumination (100 mW/$cm^2$).

• 전기화학회지
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• 제2권4호
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• pp.232-236
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• 1999

염료감응 태양전지의 전극 물질로 금속산화물인 이산화티타늄$(TiO_2)$를 사용하고, 감응제로 malachite green oxalate, basic blue3, rhodamine B, bromocresol purple 염료를 사용할 때 광전환 효율을 높이고 안정성을 향상시키기 위하여 갖추어야될 염료의 전기화학적 특성과 분광학적 특성을 조사하였다. 기준전극에 대한 염료의 산화전위와 흡수파장을 전자볼트 단위로 환산한 값을 더하여 들뜬 상태를 얻었다. $TiO_2$전극의 평활전위$(E_{fb})$를 결정하여 전도띠 끝 준위$(E_{c,s})$를 계산하였으며, 이를 염료의 들뜬 상태와 비교함으로써 합선 전류$(J_{sc})$를 향상시킬 수 있도록 염료가 갖추어야 할 특성을 알아내었다. 또한 폴리피롤 전도성 고분자를 입혀 $TiO_2$의 결함자리에서 전도띠에 있는 전자가 산화된 염료와 재결합하는 것과 $TiO_2$필름의 균열에 의한 염료의 전극반응을 방지함으로써 광전류의 안정성을 향상시킨 결과를 얻었다.