Dye-Sensitized Solar Cells Using Carbon Aerogel with Silver Sulfide Structures as Counter Electrodes

Abstract

Counter electrodes of Carbon Aerogel with Silver Sulfide Structures (CA/Ag₂S) were synthetized by cathodic deposition and solid vapor reactions. Their optical and electrical properties were determined, and they were tested as counter electrodes in dye-sensitized solar cells instead of the conventional Pt. It was found that the Ag₂S presence improves the optical and electrical conductivity of the counter electrodes. However, the impedance electrochemical spectra indicated increased resistivity (ERS) and charge transfer resistance (Rp) with increased Ag₂S structures; this suggests that the interface (CA/Ag₂S) may act as a barrier to electron transfer. Furthermore, the W1-R values decreased as the amount of Ag₂S increased, indicating a higher catalytic activity for these samples. DSSC efficiencies range from 1 to 2.5%, lower than those reported for platinum. They are a consequence of a poor fill factor (FF) that can be explained by the electrolyte loss that occurs during cell testing due to the counter electrodes’ high absorption and catalytic properties. While the performance is not ideal, the high initial Jsc values (21 mA/cm²) suggest that this system may present an opportunity as a material for energy devices.