Researchers from the group of Prof. Emilio Palomares at ICIQ have developed a new strategy to improve the efficiency and stability of dye-sensitised solar cells (DSCs). The study, published in ACS Applied Materials & Interfaces, combines molecular engineering and electrolyte innovation to address some of the key limitations that have hindered the development of this solar technology.
Unlike conventional silicon photovoltaic panels, dye-sensitised solar cells separate the functions of light absorption and charge transport. In these devices, light is absorbed by the dye molecules attached to the surface of a semiconductor material, typically titanium dioxide (TiO₂). When the dye absorbs light, it injects electrons into the semiconductor, generating an electrical current. The dye is then regenerated by a redox couple in the electrolyte, which completes the electrical cycle through the counter electrode. Because the dyes are responsible for harvesting light, and the electrolyte governs charge transport and regeneration, both components play a central role in determining the efficiency and stability of the device.
To improve the performance of the solar cells, the researchers introduced modifications in two key areas of the device. First, they developed a new dye molecule, H15, designed to complement the light absorption properties of the existing sensitiser H4. H15 absorbs blue light around 410 nm and features a prolonged excited-state lifetime, helping the device capture a broader portion of the visible spectrum when combined with H4 while reducing charge recombination at the interface with the titania film.
The second improvement was focused on the electrolyte composition. The team incorporated a hypervalent iodine(III) compound, 1-acetoxy-1,2-benziodoxol-3(1H)-one (IBA), into the cobalt-based electrolyte. The additive facilitates the charge transfer processes by accelerating the oxidation of the dye molecules and the generation of free radicals. In addition, its redox byproduct, 2-iodobenzoic acid (IA), suppresses charge recombination by coordinating with lithium ions and interacting with other electrolyte additives through halogen bonding.
According to Prof. Emilio Palomares, “the work demonstrates how combining targeted molecular design of the dye with electrolyte engineering can overcome some of the main bottlenecks affecting dye-sensitised solar cells, paving the way for more efficient and durable solar energy devices.”
Dye-sensitised solar cells have attracted academic and commercial interest for decades as a low-cost photovoltaic technology. In recent years, cobalt-based electrolytes have renewed the interest in the field because they offer higher open-circuit voltages, lower corrosivity towards metals, and greater transparency in the visible-light region compared with traditional iodide/triiodide systems. However, achieving both high efficiency and long-term operational stability has remained a significant challenge. The new study provides further evidence that the combination of tailored dye design with interfacial and electrolyte engineering addresses these limitations.
Reference publication
Synergistic Cosensitization and Redox-Triggered Interfacial Engineering for Efficient and Durable Solar Cells
Wu, H.; Marín Moncusí, L.; Perez Hernandez, J.; Martinez-Ferrero, E.; Palomares, E.
ACS Appl. Mater. Interfaces 2026, 18 (18), 26252–26262
DOI: 10.1021/acsami.6c01394
La entrada New strategy boosts the performance of dye-sensitised solar cells se publicó primero en ICIQ.