A 16.5% Efficient Perovskite Solar Cells With Inorganic NiO Film as Hole Transport Material

In this paper, the performance of perovskite solar cells (PSCs) with NiO film as a hole transfer layer (HTL) on an Fluorine-doped tin oxide (FTO) glass substrate has been investigated. It was found that the use of the FTO glass substrate to replace the Indium tin oxide (ITO) substrate in cell devices can greatly improve the fill factor (FF) and, thus, increase the power conversion efficiency (PCE). The FF can be improved by 13% and an average PCE of 16.5% (maximum 16.91%) was achieved. Furthermore, the stability test on our unencapsulated solar cells with NiO layers was conducted under AM 1.5G continuous illumination (1000 W/m ² ) in ambient air. The cell devices with C ₆₀ as an electron transfer layer (ETL) maintain over 80% of the initial efficiency for more than 14 h. There was two times improvement in device stability compared with the devices with PEDOT:PSS HTL. The PSCs with NiO HTL and C ₆₀ ETL can be a good candidate for low-cost photovoltaic devices.