Dry-Processed Carbon Nanotube Electrodes Enabling Highly Stable Perovskite Solar Cells with Near-Gold Efficiency

We report a dry fabrication strategy for carbon-based electrodes in perovskite solar cells (PSCs), using ozone-treated multiwalled carbon nanotubes (O-MWCNTs) and polytetrafluoroethylene (PTFE) fibrillation. The resulting dry-processed O-MWCNT/PTFE composite carbon electrode (OP-DPCE) exhibits high conductivity, improved interfacial contact, and stable mechanical stability. PSCs incorporating OP-DPCE achieve a power conversion efficiency of 24.84%, corresponding to ∼95% of that of Au-based PSCs. This efficiency gap arises primarily from reduced internal reflection, while hole extraction efficiency remains nearly identical to that of gold electrodes, as confirmed by photophysical and electrochemical analyses. The OP-DPCE retains 100% of its initial efficiency under 1.2 sun maximum power point tracking for 1000 h and exhibits outstanding thermal stability at 100 °C. These results demonstrate that OP-DPCE combines efficient charge transport with exceptional long-term durability. This work establishes a scalable, solvent-free approach to fabricating robust carbon electrodes, offering a promising alternative to noble metals in stable, high-performance PSCs.