Titania augmented with TiI_4 as electron transporting layer for perovskite solar cells

摘要

A novel low-temperature augmentation of TiO2 using aqueous TiI4 solution is introduced for perovskite solar cells. The device based on TiO2 augmented with TiI4 electron transporting layer shows higher power conversion efficiency of 19.4% compared to 18.4% for standard TiO2 with an additional gain in device reproducibility. Covering the surface of TiO2 with iodide ions tunes its work function and shifts its conduction band increasing the open-circuit voltage of the photovoltaic device. Moreover, the mean particle size of perovskite material on the TiI4-augmented TiO2 increased from -750 nm to -950 nm. Augmentation of the electron transporting layer provides an effective route for efficient perovskite solar cells and other applications where surface modification is required.