• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.67-72
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• 2011

The aim of this study is to evaluate how much would the building energy consumption be saved by applying DSSC BIPV window which is possible to control the transmittance and express the color in the office building. For this, physical characteristics such as transmittance and reflectance, U-factor of DSSC areanalyzed and an annual energy consumption that is connected to dimming control is calculated when DSSC BIPV window is applied by alternate clear window system. As a result, It is possible to reduce the anannual energy consumption as much as4.1% by just change the clear double window system to DSSC BIPV double window system because the major factor to reduce energy consumption in the office that has much cooling load than other building is SHGC. When the thermal insulation properties of DSSC BIPV window with low-e coating and making triple window are improved, energy saving ratio is about 9%. Plus, energy saving ratio of 25~28% in lighting energy consumption is possible when the dimming control system with DSSC BIPV window is adopt.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.158-163
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• 2011

Recently, more attention has been paid to DSC(Dye-sensitized Solar Cell) with the potential of glazing applications. The aim of the study is to analyze thermal and electrical performance according to composition of glazing with DSC. For this study, the electrical and thermal performance of glazing with DSC modules were measured and their result were compared. The measurement were performed according to the KS L2525 and with a solar simulator of DSC modules. The result show that the U-value of the DSC double glazings with clear glass and low-e glass were 2.78 $W/m^2K$ and 1.70 $W/m^2K$, respectively. The electrical measurement indicated that the electrical efficiency of the DSC double glazings with clear glass and low-e glass decreaced by 9.9% and 13.3%, respectively, compared to the DSC medules electrical performance.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.190-195
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• 2011

To investigate the photon-trapping effect and scattering layer effect of $TiO_2$ multi-layer in dye-sensitized solar cell (DSSC) and the degree of recombination of electrons at the electrode treated $TiCl_4$, we formed electrodes of different conditions and obtained the most optimal electrode conditions. To estimate characteristics of the cell, IV curve, UV-Vis spectrophotometer, electrochemical impedance spectroscopy (EIS) and incident photon-to-current conversion efficiency (IPCE) were measured. As a result, we confirmed that the multi-layer's efficiency was higher than that of monolayer in the IV curve and the performance of $TiCl_4$ treated electrode was increased according to decreasing the impedance of EIS. Among several conditions, the efficiency of the cell with scattering layer is higher than that of a layer with the base electrode about 19%. Because the light scattering layer enhances the efficiency of the transmission wavelength and has long electron transfer path. Therefore, the value of the short circuit current increases approximately 10% and IPCE in the maximum peak also increases about 12%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.100-104
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• 2011

In this work, an optimum condition of electrolytes preparation for photovoltaic cells application was investigated experimentally in terms of impedance and conversion efficiency of the cells. 3-methoxyppropionitrie and redox pairs with LiI and $I_2$ were used as stable solvents for fabrication of electrolyte. Efficiency comparison of the prepared cells carried out for various additives and ionic liquids. From the results, there was an optimum concentration (about 0.3 M) of ionic liquids for efficient cell fabrication. For case of electrolyte using single DMAp additive, the maximum conversion efficiency of the cell was 6.4%($V_{oc}$: 0.78V, $J_{sc}$: 14.4 mA/$cm^2$, ff: 0.57). For case of electrolyte using both DMAp and CEMim additives, the maximum conversion efficiency of the cell was 7.2%($V_{oc}$: 0.79V, $J_{sc}$: 16 mA/$cm^2$, ff: 0.57). From the result of electrochemical impedance measurement, both Z1 and Z3 values of binary additives-based cell decreased compared to those of single additive-based. This is due to the decreased in internal and charge transfer resistivities of the cells.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.8.1-8.1
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• 2011

Nanocrystalline titanium dioxide ($TiO_2$) materials have been widely used as an electron collector in DSSC. This is required to have an extremely high porosity and surface area such that the dye can be sufficiently adsorbed and be electronically interconnected, resulting in the generation of a high photocurrent within cells. In particular, their geometrical structures and crystalline phase have been extensively investigated as important issues in improving its photovoltaic efficiency. In this study, we present a new strategy to fabricate a photoelectrode having a periodic structured $TiO_2$ film templated from 1D or 3D polystyrene (PS) microspheres array. Monodisperse PS spheres of various radiuses were used for colloidal array on FTO glasses and two types of photoelectrode structures with different $TiO_2$ materials were investigated respectively. One is the igloo-shaped electrode prepared by $TiO_2$ deposition by RF-sputtering onto 2D microsphere-templated substrates. At the interface between the film and substrate, there are voids formed by the decomposition of PS microspheres during the calcination step. These holes might be expected to play the predominant roles as scattering spherical voids to promote a light harvesting effect, a spacious structure for electrolytes with higher viscosity and effective paths for electron transfer. Additionally the nanocrystalline $TiO_2$ phase prepared by the RF-sputtering method was previously reported to improve the electron drift mobility within $TiO_2$ electrodes. This yields solar cells with a cell efficiency of 2.45% or more at AM 1.5 illumination, which is a very remarkable result, considering its $TiO_2$ electrode thickness (<2 ${\mu}m$). This study can be expanded to obtain higher cell efficiency by higher dye loading through the increase of surface area or multi-layered stacking. The other is the inverse opal photonic crystal electrode prepared by titania particles infusion within 3D colloidal arrays. To obtain the enlargement of ordered area and high quality of crystallinity, the synthesis of titania particles coated with a organic thin layer were applied instead of sol-gel process using the $TiO_2$ precursors. They were dispersed so well in most solvents without aggregates and infused successfully within colloidal array structures. This ordered mesoporous structure provides the large surface area leading to the enough adsorption of dye molecules and have an light harvesting effect due to the photonic band gap properties (back-and-forth reflection effects within structures). A major advantage of this colloidal array template method is that the pore size and its distribution within $TiO_2$ photoelectrodes are determined by those of latex beads, which can be controlled easily. These materials may have promising potentials for future applications of membrane, sensor and so on as well as solar cells.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.201-204
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• 2005

In this research, we have studied the development of dc-dc converter suitable for the driving of mobile instruments by using a dye-sensitized solar cell(DSC). We also have designed a interlocking circuit. The circuit makes power from DSC be saved in one battery and concurrently be discharged in the other battery. As this application, mobile devices like MP3, cellular phone are drived by using power from DSC during the daytime and they can be drived by using the saving energy of the daytime during the night. Besides, we designed dc-dc converter circuit to drive low power instruments by using NMOS switch and PMOS rectifier.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.169-169
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• 2007

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1469-1470
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• 2011

본 연구에서는 ZnO 입자 다중 성장을 이용하여 DSC를 제작하여 ZnO DSC의 가능성을 점검하고자 하였다. ZnO 입자 성장은 zinc acetate solution을 이용하여 seed layer를 제작한 후 zinc nitrate와 NaOH 혼합 용액에 다중성장 시킴으로써 완성되며 이를 이용하여 ZnO DSC를 제작하였다. 그 결과 ZnO가 입자형태로 얻어짐을 확인하고 ZnO DSC를 성공적으로 제작할 수 있었으며 ZnO 입자 성장 후 소성을 통해 ZnO DSC의 성능을 0.406%에서 1.385%까지 개선시킬 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.323-325
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• 2007

$TiO_{2}$ electrode electrospun directly onto the substrate was developed for energy conversion device. To enhance energy conversion efficiency of dye-sensitized solar cell, electrodes should have higher surface area to absorb more dyes and higher conductivity to reduce recombination of generated electrons. $TiO_{2}$ nanofibers with higher surface areas were fabricated by annealing electrospun $TiO_{2}/PVP$ nanofibers at $500^{\circ}C$ for 3 hrs in air. it was revealed that $TiO_{2}$ nanofiber electrodes is hybrid with MWNT showed higher conductivity than $TiO_{2}$ semiconductor electrode possibly due to band gap change.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.695-698
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• 2004

최근 고유가 시대를 맞으면서 대체 에너지로서 무한자원인 태양빛을 이용하는 염료감응형 태양전지에 대한 관심이 급증하고 있으며, 이미 오래전부터 이에 대한 연구는 이루어져왔다. 한편, 염료감응형 태양전지를 구성하는 여러 분야 중 산화물 전극이나 전해질 또는 염료에 대한 연구는 많은 관심속에 진행되어오고 있는데 반해 상대전극에 대한 연구는 미비한 실정이다. 이에 본 연구에서는, 일반적으로 태양전지의 상대전극으로 사용되어오고 있는 Pt를 스퍼터링법 및 전기도금법을 이용하여 증착한 후 AFM을 통한 표면 형상 및 전기화학적 특성을 바탕으로 비교하여 태양전지의 상대전극으로서 적합한 제조 조건을 결정하였다.