High Efficiency Solid-State Sensitized Solar Cell-Based on Submicrometer Rutile TiO₂ Nanorod and CH₃NH₃PbI₃ Perovskite Sensitizer

TLDR

The study reports a highly efficient solar cell using submicrometer rutile TiO₂ nanorods sensitized with CH₃NH₃PbI₃ perovskite nanodots. Rutile nanorods were hydrothermally synthesized with tunable lengths by varying reaction time. The device achieved a 9.4 % PCE (15.6 mA cm⁻², 955 mV, FF 0.63) with spiro‑MeOTAD, and performance declined with longer nanorods due to reduced charge‑generation efficiency rather than increased recombination.

Abstract

We report a highly efficient solar cell based on a submicrometer (∼0.6 μm) rutile TiO2 nanorod sensitized with CH3NH3PbI3 perovskite nanodots. Rutile nanorods were grown hydrothermally and their lengths were varied through the control of the reaction time. Infiltration of spiro-MeOTAD hole transport material into the perovskite-sensitized nanorod films demonstrated photocurrent density of 15.6 mA/cm2, voltage of 955 mV, and fill factor of 0.63, leading to a power conversion efficiency (PCE) of 9.4% under the simulated AM 1.5G one sun illumination. Photovoltaic performance was significantly dependent on the length of the nanorods, where both photocurrent and voltage decreased with increasing nanorod lengths. A continuous drop of voltage with increasing nanorod length correlated with charge generation efficiency rather than recombination kinetics with impedance spectroscopic characterization displaying similar recombination regardless of the nanorod length.