Jojo Hidayat

The influence of the addition of dye surface modifier on the performance of transparent dye sensitized solar cells

The light-harvesting properties and charge injection kinetics of dye molecules play a significant role to improve the performance of dye-sensitized solar cells (DSSC). Dyes based on metal complexes with ruthenium complexes also a variety of metal–organic dyes such as Zn-porphyrin derivatives have been used. The requirements for dye to function as a photosensitizer in DSSC are the absorption in the visible or near-infrared regions of the solar spectrum and the binding to the semiconductor TiO2. In order to interact with the TiO2 surface it is preferable that the dye has a functional group as anchoring group such as carboxylic or other peripheral acidic. The carboxylic group is the most frequently used anchoring group, as in ruthenium-complex based dyes. However, carboxylic acid as an anchoring group is still not enough for conducting in electron injection to TiO2. In this research, 0.87 mg phosphonic acid is added to N719 and Z907 ruthenium-complex based dyes, rspectively, as a surface modifier to strength...

From Cell to Module: Fabrication and Long-term Stability of Dye-sensitized Solar Cells

Dye-sensitized solar cell (DSSC), which has been firstly developed by Graetzel et al back in 1991, has attracted a considerable interest since its discovery. However, two of the main challenges that the DSSC technology will have to overcome towards commercialization involve device scale-up and long-term stability. In our group, the fabrication technology of DSSC has been developed from laboratory to module scale over the past few years, nevertheless, the long-term stability has still became a major concern. In this contribution, the long-term DSSC performance in relation to their scale-up from cell to module is investigated. The photoelectrode of the DSSCs were fabricated using nanocrystalline titanium dioxide materials that were subsequently sensitized using ruthenium-based dye. Additionally, TiCl4 pre- and post-treatment were carried out to enhance the overall device efficiency. When fabricated as cells, the DSSC prototypes showed relatively stable performance during repeated tests over three months. In order to increase the output power of the solar cells, the DSSCs were then connected in a Z-type series connection to obtain sub-module panels. The DSSC sub-modules exhibit poor stability, particularly as indicated by the significant decrease in the short circuit current (ISC ). Herein, the effect of photoelectrode and sealant materials as well as module design are investigated, highlighting their profound influence upon the DSSC efficiency and long-term stability.

Stability optimization of TiO 2 dye-sensitized solar sub-modules in Z-type series interconnection

Dye sensitized solar cells (DSSC), one of the promising technology for renewable energy, has reached good performance in laboratory scale. In order to be implemented in practical use, it has become a necessity to enlarge the small size DSSC into large area (module) and to optimize stability of the module. In this study, dye sensitized solar sub-modules were fabricated with a size of 33 mm × 50 mm consisting of two active cells, each with a size of 10 mm × 50 mm, which are interconnected in type-z series. Working electrode of the sub-modules was prepared using a screen printing technique to deposit the TiO2 paste on glass conductive substrate with TiCl4 pre-treatment and post-treatment. The sub-modules were assembled using two types of sealant to investigate the effect of sealant on lifetime of the sub-module. I-V measurement using sun simulator with light intensity of 500 watt/m2 was applied twice in the range of six days to obtain the sub-module lifetime stability result. From the first I-V test, the highest photoconversion efficiency of the sub-module was 3.58%. In the second test results, the photoconversion efficiency was decreased significantly with the lowest percentage of efficiency degradation was 95.81%.

Performance analysis of flexible DSSC with binder addition

Flexible DSSC is one of modification of DSSC based on its substrate. Operating at low temperature, flexible DSSC requires a binder to improve particles interconnection. This research was done to compare the morphology and performance of flexible DSSC that was produced with binder-added and binder-free. TiO2 powder, butanol, and HCl were mixed for preparation of TiO2 paste. Small amount of titanium isopropoxide as binder was added into the mixture. TiO2 paste was deposited on ITO-PET plastic substrate with area of 1x1 cm2 by doctor blade method. Furthermore, SEM, XRD, and BET characterization were done to analyze morphology and surface area of the TiO2 photoelectrode microstructures. Dyed TiO2 photoelectrode and platinum counter electrode were assembled and injected by electrolyte. In the last process, flexible DSSCs were illuminated by sun simulator to do J-V measurement. As a result, flexible DSSC containing binder showed higher performance with photoconversion efficiency of 0.31%.

Performance of Dye-sensitized Solar Cells Based on Gel Electrolyte

Electrolyte is one of the crucial elements in dye sensitized solar cells (DSC) due to the reduction-oxidation reactions take place in this area and it has the function as the charge transfer medium. An electrolyte solution contains redox couple such as I-/I3 is filled up into a space between the photo-anodes and the counter electrode. Usually, the DSC employs a liquid electrolyte which using organic solution because easy preparation. But it has disadvantage, solvent evaporation occurs and this can decrease the cell performance. One of way to solve this problem is change liquid electrolyte to gel electrolyte. This paper describes fabrication of DSC based on gel electrolyte. Performance of the DSC is compared to the cell which using a liquid electrolyte. The result shows that the energy conversion efficiency of the solar cells based on gel electrolyte was lower than liquid electrolyte solar cell that is 1.51% and 2.23% respectively. Based on life time investigation obtained the performance of gel electrolyte solar cell is much stable than liquid electrolyte solar cell.

Optimization of TiO2 photoelectrode with titanium isopropoxide for flexible dye sensitized solar cells

Flexible DSSC uses plastic substrate such as polyethylene terephthalate (PET) to deposit photoelectrode, resulting in poor photoconversion efficiency of the solar cell due to the low temperature applied in the fabrication process. In this research, optimization process was examined in order to optimize the performance of flexible DSSC by adding titanium isopropoxide (TTIP) as a binder to TiO2 paste for DSSC photoelectrode. Small portion of TTIP with molar percentages of 0%, 5%, and 10% were added to a mixture of TiO2 nanocrystaline, butanol, DI water, and reflector powder. The mixtures were stirred using a magnetic stirrer for 24 hours. Each of various pastes was then deposited on a plastic substrate with doctor blade method on 1 cm2 area. The films were sintered at temperature of 150 °C for 4 hours and soaked in dye solution for 24 hours. Furthermore, TiO2 photoelectrode and Pt counter electrode were assembled and injected by electrolyte. Flexible DSSCs were characterized by SEM and XRD to determine thei...