RK1 achieves one of the best output power conversion efficiencies for a solar cell based on the iodine/iodide electrolyte, combining high efficiency and outstanding stability.
We demonstrate that the combination of this dye with an ionic liquid electrolyte allows the fabrication of solar cells that show power conversion efficiencies of up to 7.36% that are highly stable with no measurable degradation of initial performances after 2200 h of light soaking at 65°C under standard irradiation conditions.
In addition, the electrolytes (I − /I 3−) can absorb visible light (λ = ∼430 nm), leading to photocurrent loss in the DSSC. Therefore, the introduction of iodide/iodine-free electrolytes or hole-transport materials (HTMs) could lead to cost-effective alternatives to TiO 2 DSSCs.
Dye-sensitized solar cells (DSSCs) are built from nanocrystalline anatase TiO 2 with a 101 crystal face (nc-TiO 2) onto which a dye is absorbed, ruthenium complex sensitizers, fluid I − /I 3− redox couples with electrolytes, and a Pt-coated counter electrode.
Iodine can also act as an oxidizing agent, corroding metals, such as the grid metal Ag and the Pt mediator on the cathode, especially in the presence of water and oxygen. In addition, the electrolytes (I − /I 3−) can absorb visible light (λ = ∼430 nm), leading to photocurrent loss in the DSSC.
Finally, the working and counter electrodes were sandwiched together using a thin thermoplastic (Surlyn) frame that melts at 100°C. The volatile electrolyte used consisted of 0.5 M 1-butyl-3- methylimidazolium iodide (BMII), 0.1 M lithium iodide, 0.05 M iodine and 0.5 M tert-butylpyridine in acetonitrile.
In this review, we will provide an overview of iodine/iodide-free redox systems for liquid electrolytes, and reveal that the design of an efficient redox system should combine with appropriate sensitizing dyes which is the pivotal challenge for …