Flexible Copper Mesh Electrodes with One-Step Ball-Milled TiO2 for High-Performance Dye-Sensitized Solar Cells

Advancements in flexible, low-cost, and recyclable alternatives to transparent conductive oxides (TCOs) are critical challenges in the sustainability of third-generation solar cells. This work introduces a copper mesh-based transparent electrode for dye-sensitized solar cells, replacing conventional fluorine doped-tin oxide (FTO)-coated glass to simultaneously reduce spectral reflection losses, enhance mechanical flexibility, and enable material recyclability. Titanium dioxide (TiO2) photoanodes were synthesized and directly deposited onto the mesh via a single-step, low-energy ball milling process, which eliminates TiO2 paste preparation and high-temperature annealing while reducing fabrication time from over three hours to 30 min. Structural and surface analyses confirmed the deposition of high-purity anatase-phase TiO2 with strong adhesion to the mesh branches, enabling improved dye loading and electron injection pathways. Optical studies revealed higher visible light absorption for the copper mesh compared to FTO in the visible range, further enhanced upon TiO2 and Ru-based dye deposition. Electrochemical measurements showed that TiO2/Cu mesh electrodes exhibited significantly higher photocurrent densities and faster photo response rates than bare Cu mesh, with dye-sensitized Cu mesh achieving the lowest charge transfer resistance in impedance analysis. Techno–economic and sustainability assessments revealed a decrease of 7.8% in cost and 82% in CO2 emissions associated with the fabrication of electrodes as compared to conventional TCO electrodes. The synergy between high conductivity, transparency, mechanical durability, and a scalable, recyclable fabrication route positions this architecture as a strong candidate for next-generation dye-sensitized solar modules that are both flexible and sustainable.