Study of the Effect of Electrochemical GO Reduction Degree as a Coating for TiO2 Modified with Copper Ions Through Electrophoresis for Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) are a promising alternative to traditional silicon-based technologies due to their low production costs, ease of fabrication, and wide range of applications. Among the semiconductors used in DSSCs, TiO2 stands out for its simple, inexpensive synthesis and lower environmental impact. However, TiO2 has limitations due to its wide bandgap and high charge-carrier recombination. In this study, the incorporation of rGO and its effect on the degree of GO reduction on Cu-doped TiO2 particles were evaluated to enhance light interaction, improve electronic mobility, and suppress recombination. Electrophoretic deposition was employed as an alternative method to obtain Cu-doped, rGO-decorated mesoporous TiO2 films, which were evaluated for power conversion efficiency (PCE) in DSSCs. The materials were characterized using SEM, ICP-OES, UV-Vis, XRD, BET, DLS, and TEM, while the photoanodes were analyzed using FTIR, chronoamperometry, and photovoltaic efficiency tests. The results showed clusters between 1.4 and 2.6 µm, confirming doping, a decrease in the energy gap to 2.99 eV, a stable anatase crystalline phase, and an increase in the specific surface area to 234.82 m2/g. The fabricated cells exhibited a PCE of 2.26% with a TiO2:Cu-rGO photoanode after 20 min of GO reduction, compared to 0.96% for DSSCs with a conventional configuration.