Outstanding photocurrent density and incident photon-to-current conversion efficiency of liquid-state NiO Perovskite-sensitized solar cells

© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The efficiency and photocurrent density reported for p-type-sensitized solar cells up to now are still lagging behind that of the n-type counterparts, limiting the successful development of p–n tandem cells. To circumvent this issue, NiO thin film is fabricated by the aerosol-assisted chemical vapor deposition (AACVD) technique and used in p-type solar cells. A systematic study is conducted to comprehend the correlation between NiO thickness and the power conversion efficiency (PCE) of liquid-state NiO-based sensitized solar cells. By carefully designing the cell components, this type of device demonstrates the highest photocurrent density (Jsc) exceeding 18 mA cm−2 when using iodine/triiodide as the redox shuttle matching the one produced by the TiO2 counterpart. This is accomplished by 1) using the AACVD technique for the one-step deposition of compact and mesoporous NiO electrodes, 2) optimizing the thickness of the NiO layer through controlling the deposition time, and 3) adopting methylammonium lead iodide (CH3NH3PbI3) as a light harvester prepared via a sequential deposition method.