High efficiency solid-state sensitized solar cell-based on submicrometer rutile TiO_2 nanorod and CH_3NH_3PbI_3 perovskite sensitizer

摘要

We report a highly efficient solar cell based on a submicrometer (～0.6 μm) rutile TiO_2 nanorod sensitized with CH_3NH _3PbI_3 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.