Toward Printable Sensitized Mesoscopic Solar Cells: Light-Harvesting Management with Thin TiO2 Films

Sensitized mesoscopic solar cells can exhibit high performance and processability by the use of a thin semiconductor layer in combination with a sensitizer of superior light-harvesting ability. This combination is an important key toward the realization of high-efficiency flexible solar cells using solution-based, rapid roll-to-roll printing processes. To this goal, preparation of a binder-free TiO2 paste is presented as a key process to low-temperature plastic electrode fabrication. For the future challenges of printable sensitized solar cells, this Perspective is focused on the importance of sensitizer choice for thin TiO2 films with regards to optimum light harvesting, showing photovoltaic behaviors of organic dye sensitizers and lead halide perovskite nanocrystals as inorganic sensitizers. Further, the author offers a comparison of the light-harvesting ability between organic dye sensitizers and inorganic quantum dot size sensitizers based on optical extinction coefficients and the surface density of ...