Dye-Sensitized Solar Cell Sealant
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ThreeBond Technical News Issued January 1, 2014 Dye-Sensitized Solar Cell Sealant Introduction Renewable energy development is currently underway all across the world in an effort to ensure sufficient energy resources. Among such research, there are high expectations for the permanent and clean energy produced by solar cells, so a variety of solar power generation system specifications are being constructed. While silicon solar cells are currently the most widely used, research on alternative materials is aggressively pursued due to the high cost of silicon and supply issues concerning silicon materials. One of these alternatives is the dye-sensitized solar cell (hereafter abbreviated as DSSC). As we mentioned in Technical News No. 65, ThreeBond has long been engaged in the development of DSSC sealant and we are pleased to announce the release of three dye-sensitized solar cell sealants, ThreeBond 3035B, ThreeBond 3035C and ThreeBond 3118. In this article, we will explore their properties advantages and usage. Hereafter, ThreeBond is abbreviated as TB.

Solar cells are systems that convert energy from sunlight into electrical energy. They are classified by materials used as indicated in Figure 1. Dye-sensitized solar cells are an organic type of solar cell where dyes absorbed within titanium oxide nanostructures absorb light energy, convert it into electrons via electrochemical properties then extract it as electricity. Though inferior to the more widely used silicon solar cells in terms of power generation efficiency, their materials are inexpensive, they are easy to construct and their design is excellent. They can also generate power...

DSSC are structured as indicated in Figure 3 and mainly made of the following materials. • Substrate (glass or film with a transparent conductive film) Main seal Interface leakage Permeation leakage Interface leakage Permeation leakage • Electrolytic solution • Main sealant that encapsulates the electrolytic solution • End sealant that fills the electrolytic solution injection hole Cell diagram Fig. 4 DSSC Electrolytic Solution Leakage End sealant (seals the electrolytic solution injection hole) Substrate Mixture with outside moisture causes the dye to detach as well as interior cell...

5-1 DSSC Sealant TB3035B TB3035B is an acrylic DSSC sealant that cures when exposed to UV or visible light with a wavelength of 200 to 420 nm. (Fig. 6). Mass change rate (%) In the ODF (One Drop Fill) method, the main sealant is either screen printed or dispense coated followed by injection of electrolytic solution. Once the substrates are stacked, they are exposed to UV rays to cure the main sealant. Epoxy resin Silicone resin Urethane resin Acrylic resin Fig. 7 Post-Curing Electrolyte Resistance per Resin Electrolytic solution injection When viewed from the side... Completely covered with...

TB3035B characteristics are indicated in Table 1. Using acrylic resin that erodes very little in electrolytic solution further increases electrolytic solution resistance. Figure 7 compares the electrolytic solution resistance of conventional reactive resin and TB3035B. Figure 9 shows the results of the UV exposure test regarding electrolytic solution leakage performance depending on sealant width and sealant height. This figure indicates that a wide seal width and a low seal height improve electrolytic solution leakage performance strength. This figure indicates that TB3035B has a lower...

TB3118 characteristics are indicated in Table 1. TB3118 contains an epoxy resin that does not mix well with electrolytic solution and has a high crosslink density, making it excellent for water and electrolyte protection. As shown in Figure 7, this results in electrolyte solution resistance that is higher than that of conventional resins. TB3118 sealing performance was tested using dummy cells, the results of which are indicated in Figure 13 and 14. The wider sealant width and lower sealant height of TB3118 also improve electrolyte solution leakage control. Figure 15 shows electrolytic...

Additionally, the film contains a UV ray absorber to prevent deterioration, but this cuts UV ray wavelengths needed for TB3118 to cure, making it impossible to use as a DSSC main sealant. However, as indicated in Table 1, low moisture and solvent permeability provide excellent protection, and crosspeeling bonding strength is high, giving it the durability needed for use as a main sealant. There are certain main and end sealant combinations that cannot be used depending on material composition. This necessitates the selection of sealant that can handle a variety of substrate materials,...

Closing We are pleased to present our DSSC sealant. Now that DSSC is commercially available, we expect that its utilization will only continue to expand. With this expansion, we are certain that what is required of sealants will also continue to grow. At ThreeBond, we are dedicated to product and technology development centered on market trends that ensures our product development’s continued contribution to the manufacturing industry. <References> Technical News No. 65, Dye-Sensitized Solar Cell Sealant ThreeBond Fine Chemical Co., Ltd. R&D Headquarters Development Division, Functional...