Ti-MOF-derived TiO₂/C as an efficient electron transport layer for high-performance perovskite solar cells

Perovskite solar cells (PSCs) have emerged as promising candidates for next-generation photovoltaic technology due to their high efficiency and low fabrication cost. However, the development of stable and non-toxic electron transport materials (ETMs) remains a major challenge limiting commercial viability. In this work, we report a novel electron transport layer (ETL) based on TiO₂/C composites derived from a titanium-based metal-organic framework (Ti-MOF) via controlled pyrolysis. The resulting TiO₂/C nanocomposite exhibit a porous structure, enhanced electrical conductivity, and improved energy level alignment with the perovskite absorber. Comprehensive characterization of the material's structural, morphological, optical, and thermal properties was performed. When integrated into PSCs, the TiO₂/C-based ETL led to superior device performance compared to conventional TiO₂, with enhanced electron extraction, reduced trap-state density, and improved perovskite film quality. The best-performing device achieved a short-circuit current density (Jsc) of 19.39 mA cm⁻², an open-circuit voltage (Voc) of 0.983 V, a fill factor of 0.786, and a power conversion efficiency (PCE) of 17.6 % under standard AM 1.5G illumination (100 mW cm⁻²), with excellent repeatability. These results demonstrate a simple and effective strategy for improving both the efficiency and stability of PSCs using MOF-derived TiO₂/C ETLs, offering a promising pathway for scalable and high-performance solar cell technologies.