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 (JSC), 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%.