Novel electrode and electrolyte membranes: Towards flexible dye-sensitized solar cell combining vertically aligned TiO2 nanotube array and light-cured polymer network

Integration of dye-sensitized solar cells (DSSCs) in portable devices is a target currently on the crest of the wave in the scientific community. To this purpose, some modifications of the cell standard structure are mandatory, starting from its flexibilization. Among all, electrolytes based on self-standing membranes may be the best option for the fabrication of flexible, efficient and durable devices. Thus, we report on an innovative combination of vertically aligned TiO2 nanotubes, grown onto bendable titanium mesh, and a photocured polymer electrolyte membrane to fabricate a flexible DSSC. The photovoltaic performances were deeply investigated by electrical measurements and impedance spectroscopy, and the electrochemical behavior of the TiO2- and polymer-based membranes is reported. The careful selection of the materials and the synergistic effect of the two membrane properties led to the most efficient quasi-solid flexible DSSC ever produced, with a sunlight to electricity conversion efficiency equal to 3.4% under 1 sun irradiation.