Efficient charge-transport in hybrid lead iodide perovskite solar cells

Abstract

Recently, highly efficient solar cells based on organic–inorganic perovskites have been intensively studied for developing fabricating methods and device structures. To improve the performance of perovskite film devices, delicate control of charge transfer material interconnectivity is required. Here, controlling the mesoporous TiO₂ structure improves their charge collection and injection rate, and allows substantial enhancement of the corresponding device performance. We found that increasing the TiCl₄ processing time deteriorates the device performance by introducing a large amount of excessively large perovskite particles, surface roughness and charge recombination. Proper TiCl₄ processing dramatically improves the charge transport within the electron transfer layer, explaining the efficient performance of meso-superstructured solar cells.