Reaction between oxide sealant and liquid electrolyte in dye-sensitized solar cells

The iodide and tri-iodide reduction–oxidation couples in the liquid electrolyte of dye-sensitized solar cells (DSSCs) are very reactive and corrosive with the other components of the DSSCs, especially the sealing material. A leakage of the liquid electrolyte to cells generally occurs in the DSSCs because of a chemical reaction between the sealing material and the electrolyte. This leakage is correlated to the long-term stability and energy conversion efficiency of the dye-sensitized solar module. This study examined the reactions between the electrolyte and the glass using a leaching test with the aim of using this material as the matrix of the sealing materials in DSSCs. The prepared samples were evaluated using an inductively coupled plasma spectroscope, a nanoindentation test, an atomic force microscope and a contact angle analyzer. After the leaching test, the zinc and boron ions from the glass were leached into the electrolyte after immersion for 1 h. The elastic modulus, hardness, and surface roughness of the glass changed after the formation of the leached layer of the glass surface. The results suggested that the compositions of the oxide sealant should be considered in terms of the chemical stability in the electrolyte.