TiO2 nanocrystals synthesized by Laser Pyrolysis for the Up-Scaling of Efficient Solid-Stage Dye-Sensitized Solar Cells
Résumé
A crucial issue regarding emerging nanotechnologies remains the up-scaling of new functional nanostructured materials towards their implementation in high performance applications on a large scale. In this context, we demonstrate high efficiency solid-state dye-sensitized solar cells prepared from new porous TiO2 photoanodes based on laser pyrolysis nanocrystals. This strategy exploits a reduced number of processing steps as well as non-toxic chemical compounds to demonstrate highly porous TiO2 films. The possibility to easily tune the TiO2 nanocrystal physical properties allows us to demonstrate all solid-state dye-sensitized devices based on a commercial benchmark materials (organic indoline dye and molecular hole transporter) presenting state-of-the-art performance comparable with reference devices based on a commercial TiO2 paste. In particular, a drastic improvement in pore infiltration, which is found to balance a relatively lower surface area compared to the reference electrode, is evidenced using laser-synthesized nanocrystals resulting in an improved short-circuit current density under full sunlight. Transient photovoltage decay measurements suggest that charge recombination kinetics still limit device performance. However, the proposed strategy emphasizes the potentialities of the laser pyrolysis technique for up-scaling nanoporous TiO2 electrodes for various applications, especially for solar energy conversion.