摘要
A novel low-temperature augmentation of TiO 2 using aqueous TiI 4 solution is introduced for perovskite solar cells. The device based on TiO 2 augmented with TiI 4 electron transporting layer shows higher power conversion efficiency of 19.4% compared to 18.4% for standard TiO 2 with an additional gain in device reproducibility. Covering the surface of TiO 2 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 TiI 4 -augmented TiO 2 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.