TiO₂ Nanoparticles/Nanotubes for Efficient Light Harvesting in Perovskite Solar Cells.

To enhance the light harvesting capability of perovskite solar cells (PSCs), TiO₂ nanoparticles/nanotubes (TNNs) were incorporated into the active layer of PSCs. The TNN-containing cells showed a substantial increase in photocurrent density (J(SC)), from 23.9 mA/cm² without nanotubes to 25.5 mA/cm², suggesting that the TiO₂ nanotubes enhanced the charge conduction and harvested more sunlight, which was attributed to the Mie scattering effect. Compared to the power conversion efficiency (PCE) of TiO₂ nanoparticles in the active layer (14.16%), the TNN-containing cells with optimal loading of 9 wt % TiO₂ nanotubes showed a high PCE of 15.34%.