High Consistency Perovskite Solar Cell with a Consecutive Compact and Mesoporous TiO₂ Film by One-Step Spin-Coating

Generally, in classic mesoscopic perovskite solar cells (PSCs), the compact blocking layer and mesoporous scaffold layer prepared by two steps or more will inevitably form an interface between them. It is undoubted that the interface contact is not conducive to electron transport and would increase the recombination in the device, resulting in the inferior performance of PSCs. In this work, we constructed a consecutive compact and mesoporous (CCM) TiO₂ film to substitute the compact blocking layer and scaffold layer for mesoscopic PSCs. The bottom of the CCM TiO₂ film was dense and the top was mesoporous with large uniform macropores. The two parts of the film were consecutive, which could promote the electron transport rate and decrease the charge recombination effectively. Moreover, due to the existence of macropores in the CCM TiO₂ film, it was propitious to the deposition of perovskite and charge separation for the perovskite layer. Over 15.0% of average power conversion efficiency (PCE) with high consistency photovoltaic performances was achieved for the CCM TiO₂ film based mesoscopic PSCs, which is higher than that with a classic mesoporous structure.