• Bulletin of the Korean Chemical Society
• /
• v.34 no.8
• /
• pp.2491-2494
• /
• 2013

The effect of additives in an electrolyte solution on the conversion efficiency of a dye sensitized solar cell was investigated. A density functional theory (DFT) method was used to examine the physical and chemical properties of nitrogen-containing additives adsorbed on a $TiO_2$ surface. Our results show that additives which cause lower partial charges, higher Fermi level shifts, and greater adsorption energies tend to improve the performance of DSSCs. Steric effects that prevent energy losses due to electron recombination were also found to have a positive effect on the conversion efficiency. In this work, 3-amino-5-methylthio-1H-1,2,4-triazole (AMT) has been suggested as a better additive than the most popular additive, TBP, and verified with experiments.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.1
• /
• pp.172-176
• /
• 2009

The nature and morphology of titanium dioxide films play a significant role in determining the overall efficiency of dye-sensitized solar cell (DSSCs). In this work, the preparation of nanostructured titania particles by sol-gel method (SG-$TiO_2$) and its characterization were investigated for the application of DSSCs. The samples were characterized by XRD, XPS, FE-SEM, BET and FT-IR analysis. The energy conversion efficiency of SG-$TiO_2$ was approximately 8.3 % under illumination with AM 1.5 (100 mW/$cm^2$) simulated sunlight. DSSCs made of SG-$TiO_2$ nanocrystalline films as photoanodes achieved better energy conversion efficiency compared to those prepared using commercially available Degussa P25.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.89.2-89.2
• /
• 2010

The dye-sensitized solar cell (DSSC) is a device for the conversion of visible light into electricity, based on the sensitization of wide bandgap semiconductors. The performance of the cell mainly depends on a dye used as sensitizer. The absorption spectrum of the dye and the anchorage of the dye to the surface of $TiO_2$ are important parameters determining the efficiency of the cell. Generally, transition metal coordination compounds(ruthenium polypyridyl complexes) are used as the effective sensitizers, due to their intense charge-transfer absorption in the whole visible range and highly efficient metal-to ligand charge transfer. However, ruthenium polypyridyl complexes contain a heavy metal, which is undesirable from point of view of the environmental aspects. Moreover, the process to synthesize the complexes is complicated and costly. Alternatively, organic dyes can be used for the same purpose with an acceptable efficiency. The advantages of organic dyes include their availability and low cost. We designed and synthesized a series of organic sensitizers containing long wavelength absorption-chromophores for the dye sensitized solar cell. The DSSC composed of Blue-chromophores for the sensitization absorbed long wavelength region which is different also applied into the dye-cocktail (mixing) system. The photovoltaic property of DSSCs organic long wavelength absorption-chromophores were measured and evaluated by comparison with that of individual chromophores.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.118.1-118.1
• /
• 2011

The dye-sensitized solar cell (DSSC) is a device for the conversion of visible light into electricity, based on the sensitization of wide bandgap semiconductors. The performance of the cell mainly depends on a dye used as sensitizer. The absorption spectrum of the dye and the anchorage of the dye to the surface of TiO2 are important parameters determining the efficiency of the cell. Generally, transition metal coordination compounds(ruthenium polypyridyl complexes) are used as the effective sensitizers, due to their intense charge-transfer absorption in the whole visible range and highly efficient metal-to ligand charge transfer. However, ruthenium polypyridyl complexes contain a heavy metal, which is undesirable from point of view of the environmental aspects. Moreover, the process to synthesize the complexes is complicated and costly. Alternatively, organic dyes can be used for the same purpose with an acceptable efficiency. The advantages of organic dyes include their availability and low cost. We designed and synthesized a series of organic sensitizers containing long wavelength absorption-chromophores for the dye sensitized solar cell. The DSSC composed of Blue-chromophores for the sensitization absorbed long wavelength region which is different also applied into the dye-cocktail (mixing) system. The photovoltaic property of DSSCs organic long wavelength absorption-chromophores were measured and evaluated by comparison with that of individual chromophores.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.1
• /
• pp.76-80
• /
• 2011

The ITO/Cabon Nano Tube (CNT) nano composites were deposited by nano cluster deposition (ITO) and arc discharge deposition (CNT) on glass substrates. The structural, optical and photovoltaic performance of ITO/CNT nano composites as a counter electrode of dye-sensitized solar-cells (DSSCs) such films were investigated. At low temperature below $250^{\circ}C$, the ITO films deposited on CNT. The ITO/CNT nano composit showed a good optical and electrical property for the counter electrode of DSSCs. When the as-prepared ITO/CNT nano composites are used for the counter electrodes, the photovoltaic parameters are $V_{OC}$ = 0.69 V, $J_{SC}$ = 5.69 mA/$cm^2$, FF = 0.32, and $\eta$ = 0.53 %. The ITO/CNT nano composites showed the possibility for the counter electrode applications of DSSCs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.7
• /
• pp.558-562
• /
• 2012

As an alternative energy, Dye-sensitized solar cells (DSSCs) have received much attention due to low cost manufacturing procedure and high energy consumption rate. Incorporating scattering centers in the nanocrystalline photoanode or additional scattering layers on the nanocrystalline photoanode is an effective way to enhance the light harvest efficiency of the photoanode and the performance of dye-sensitized solar cells (DSSCs). The light scattering abilities of these scattering layers also depend on the relative sizes and phase of the particles in the layers. A higher surface area is normally obtained using large particle sizes. Therefore, transparent high surface area $TiO_2$ layers and an additional scattering layer consisting of $TiO_2$-Rutile 500 nm paste with relatively larger particles are attractive. In this work, we investigates the applicability of a hybrid $TiO_2$ electrode (or a working electrode with a light scattering layer) in a DSSCs. We fabrication various thin film using $TiO_2$ paste 20 nm and $TiO_2$ paste 500 nm. As a result, the efficiency of the a single structure thin film was 3.35% and the efficiency as scattering layer of hybrid structure thin film was 4.36%, 4.73%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.28 no.3
• /
• pp.180-184
• /
• 2015

Stainless steel (SS) mesh was used to fabricate photoelectrode for flexible dye-seisitzed solar cells (DSSCs) in order to evaluate them as replacements for more expensive transparent conductive oxide(TCO). We fabricated the DSSCs with new type of photoelectrode, which consisted of flexible SS mesh coated with 100 nm thickness titanium (Ti) protective layer deposited using electron-beam deposition system. SS mesh DSSCs with protective layer showed higher efficiency than those without a protective layer. The best cell property in the present study showed the open circuit voltage (Voc) of 0.608 V, short-circuit current density (Jsc) of $5.73mA\;cm^{-2}$, fill factor (FF) of 65.13%, and efficiency (${\eta}$) of 2.44%. Compared with SS mesh based on DSSCs (1.66%), solar conversion of SS mesh based on DSSCs with protective layer improved about 47%.

• Journal of the Korean Ceramic Society
• /
• v.52 no.5
• /
• pp.384-388
• /
• 2015

We prepared blocking layers by adding 0.0 ~ 0.6 wt% nano diamond blends (DBs) to $TiO_2$ blocking layers to improve the energy conversion efficiencies (ECEs) of dye sensitized solar cells (DSSCs). TEM and micro-Raman spectroscopy were used to characterize the microstructure and phases of DBs, respectively. Optical microscopy and FE-SEM were used to analyze the microstructure of the $TiO_2$ blocking layer with DBs. UV-VIS-NIR spectroscopy was used to determine the absorbance of the working electrodes. A solar simulator and a potentiostat were used to determine the photovoltaic properties and the impedance of the DSSCs with DBs. From the results of the DBs analysis, we determined a 6.97 nm combination of nano diamonds and graphite. We confirmed that ECE increased from 5.64 to 6.48 % when the added DBs increased from 0.0 to 0.2 wt%. This indicates that the effective surface area and electron mobility increased when DBs were added to the $TiO_2$ blocking layer. Our results indicate that the ECE of DSSCs can be enhanced by adding an appropriate amount of DBs to the $TiO_2$ blocking layers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.435-436
• /
• 2008

Dye-sensitized Solar Cells(DSSCs) which convert incident sun light into electricity were expected to overcome global warming and depletion of fossil fuels. And it is one of study that is lately getting into the spotlight because manufacturing method is more simple and inexpensive than existing silicon solar cells. In this respect, DSSCs are in the limelight as the next generation solar cells. DSSCs are generally composed of a dye-modified $TiO_2$ photoelectrode, a Pt counter electrode, and an electrolytes containing a redox couple$(I^-/I_3^-)$. Among these elements, pt electrode were prepared by applying electric potential to FTO substrate in the $H_2PtCl_6$ solution. In this study, we report the solar cell efficiency depending on $PtCl_4$ concentration change. $PtCl_4$ concentration was 1mM, 5mM, 10mM, and 20mM, and adhered on FTO glass substrate by sintering process. When applied each $PtCl_4$ counter electrode on DSSC, the best efficiency was found at 10mM of $PtCl_4$ concentration. The catalyst promotes the movement of electron from the counter electrode to the electrolyte the higher the molarity, the better the efficiency. However, in case of 20mM, it is estimated that over-deposited $PtCl_4$ tends to restrict the movement of electron due to its bundle formation.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.147-149
• /
• 2005

Synthesis of $TiO_2$ nanoparticle paste is one of the important technologies in dye-sensitized solar cells (DSSC). Performances of the DSSCs from synthesized $TiO_2$ nanoparticle paste was similar or better than those from commercial sources. In addition. cell efficiency was further improved by using large scattering $TiO_2$ particles. Those results was utilized in manufacturing high efficiency DSSC modules.