Enhancing the stability and efficiency of dye-sensitized solar cells with MIL-125 metal-organic framework as an electrolyte additive
Ayagoz Ibrayeva, Zulfiya Imanbekova, Urker Abibulla, Yerbolat Tashenov, Bakhytzhan Baptayev, Mannix P. Balanay
Abstract
This study investigates how to improve the stability of liquid electrolyte (LE) dye-sensitized solar cells (DSSCs) by incorporating a titanium-based metal-organic framework (MIL-125). MIL-125, created through the coordination of Ti 4+ ions with benzene-1,4-dicarboxylic acid, forms a structure that can effectively accommodate I − /I 3 − electrolytes, resulting in a MIL-125@electrolyte assembly. This innovative assembly successfully prevents electrolyte leakage while preserving the LE properties. The study examines how the MIL-125@electrolyte enhances both stability and power conversion efficiency (PCE) of DSSCs. The inclusion of the large-surface-area of MIL-125 improves ionic conductivity, reduces charge transfer resistance, and stops leakage. The optimized MIL-125@electrolyte achieves a high PCE of 10.51%, with a peak value of 10.99%, and a notable short-circuit current density of 20.97 mA/cm², peaking at 22.27 mA/cm², under standard AM 1.5, 100 mW/cm² conditions. It maintains about 75% of its PCE after 1400 h at approximately 23 °C. For indoor applications using LED lighting, the quasi-solid-state DSSC reaches a record PCE of 27.6%, with an average of 25.9%, under 6000 lx illumination.